If your OBD-II scanner displays P0029, your vehicle’s Engine Control Module (ECM) or Powertrain Control Module (PCM) has detected that the Bank 2 exhaust valve control solenoid circuit or exhaust camshaft-control system is not operating within its expected range.
The generic description for P0029 is:
Exhaust Valve Control Solenoid Circuit Range/Performance Bank 2
Depending on the vehicle manufacturer, the affected component may also be called the:
- Exhaust valve control solenoid
- Exhaust valve timing control solenoid
- Exhaust VVT solenoid
- Oil control valve
- Exhaust camshaft actuator
- Camshaft timing control valve
- Variable camshaft timing solenoid
- Variable valve-lift control solenoid
P0029 is a range/performance code. This means the ECM may still be able to energize the solenoid, but the Bank 2 exhaust valve-control system does not respond correctly or operates outside its calibrated limits.
The underlying problem may be:
- Electrical
- Hydraulic
- Mechanical
- Sensor-related
- Software-related
Common P0029 causes include:
- Dirty or incorrect engine oil
- Low engine-oil level
- Low or unstable oil pressure
- A sticking Bank 2 exhaust valve control solenoid
- A failed solenoid coil
- A clogged solenoid filter screen
- Restricted oil passages
- Damaged wiring or connectors
- A failed exhaust camshaft phaser
- A variable valve-lift mechanism fault
- Incorrect mechanical timing
- A faulty camshaft or actuator position sensor
- An ECM software or driver problem
P0029 should be diagnosed promptly. Some vehicles may continue running with only an illuminated Check Engine Light, but the ECM may disable Bank 2 exhaust variable valve timing or valve-lift operation.
This can cause:
- Rough idle
- Poor acceleration
- Reduced fuel economy
- Increased emissions
- Engine misfires
- Reduced turbocharger response
- Possible timing-system damage
Looking for more diagnostic resources? Browse our complete OBD-II libraries:
- Complete OBD-II Code Library: https://my.prostreetonline.com/dtc-obdii/
- Body (B) Codes: https://my.prostreetonline.com/dtc-doctor/b-code-obd-ii-codes/
- Chassis (C) Codes: https://my.prostreetonline.com/dtc-doctor/c-code-obd-ii-codes/
P0029 Quick Facts
| Item | Information |
|---|---|
| OBD-II code | P0029 |
| Official description | Exhaust Valve Control Solenoid Circuit Range/Performance Bank 2 |
| Category | Powertrain |
| System | Exhaust valve, variable valve timing or variable valve-lift control |
| Code type | Generic SAE powertrain code |
| Affected bank | Bank 2 |
| Severity | Moderate to high |
| Safe to drive? | Usually for a limited distance; diagnose promptly |
| Most common causes | Dirty oil, sticking solenoid, wiring fault, failed actuator |
| Typical repair cost | $60–$2,500+ |
What Does the P0029 Code Mean?
P0029 means the ECM has detected that the Bank 2 exhaust valve control solenoid or related exhaust camshaft-control system is operating outside its expected electrical, hydraulic or mechanical range.
A range/performance trouble code differs from a simple circuit-open or circuit-short code.
The circuit may still be complete, but the ECM determines that the system is not behaving as commanded.
The ECM may detect that:
- Solenoid current is too high or too low.
- Circuit resistance is outside specification.
- The solenoid does not respond when commanded.
- The Bank 2 exhaust camshaft does not reach its requested position.
- The valve-control mechanism moves too slowly.
- The actuator remains stuck in one operating mode.
- Actual actuator position does not match the commanded position.
- Hydraulic pressure is insufficient.
- The system cannot complete its self-test.
- The solenoid operates electrically but performs poorly mechanically.
P0029 may therefore indicate:
- A failed solenoid
- A wiring or connector fault
- Restricted engine-oil flow
- A failed exhaust camshaft actuator
- A variable valve-lift system problem
- Incorrect camshaft timing
- A faulty feedback sensor
- An ECM control problem
Related trouble codes include:
- P0023: “B” Camshaft Position Actuator Circuit Bank 2
- P0024: “B” Camshaft Position Timing Over-Advanced Bank 2
- P0025: “B” Camshaft Position Timing Over-Retarded Bank 2
- P0019: Crankshaft Position–Camshaft Position Correlation Bank 2 Sensor B
- P0026: Intake Valve Control Solenoid Circuit Range/Performance Bank 1
- P0027: Exhaust Valve Control Solenoid Circuit Range/Performance Bank 1
- P0028: Intake Valve Control Solenoid Circuit Range/Performance Bank 2
What Does Bank 2 Mean?
Bank 2 is the side of the engine that does not contain cylinder number one.
Bank 2 is found on engines with more than one cylinder bank, including:
- V6 engines
- V8 engines
- V10 engines
- V12 engines
- Horizontally opposed engines
On these engines:
- Bank 1 contains cylinder number one.
- Bank 2 is the opposite cylinder bank.
Inline engines generally have only one cylinder bank and should not store a true Bank 2 exhaust valve-control code.
Bank 2 may be located on either side of the vehicle depending on the engine design.
Confirm Bank 2 using:
- Manufacturer service information
- Cylinder-numbering diagrams
- Firing-order diagrams
- Underhood labels
- Professional repair databases
Do not assume Bank 2 is always the driver side or passenger side.
Testing the wrong bank can lead to unnecessary parts replacement and leave the actual fault untouched.
What Is an Exhaust Valve Control Solenoid?
The exhaust valve control solenoid is an electronically operated component used to change some aspect of exhaust-valve or exhaust-camshaft operation.
Depending on the engine, it may control:
- Exhaust camshaft timing
- Oil flow to an exhaust camshaft phaser
- Exhaust valve lift
- Exhaust valve duration
- Internal exhaust-gas recirculation
- A multi-stage rocker-arm mechanism
- Camshaft actuator locking and release
The ECM commonly controls the solenoid using a pulse-width-modulated electrical signal.
Rather than simply switching the solenoid fully on or off, the ECM may rapidly cycle the control circuit to regulate oil flow precisely.
On a hydraulic variable valve timing system, the solenoid redirects pressurized engine oil into different chambers within the exhaust camshaft phaser.
On a variable valve-lift system, it may direct oil pressure to:
- Rocker arms
- Locking pins
- Valve-lift actuators
- Other valvetrain components
Manufacturer terminology varies, so identify the exact system before testing or ordering replacement parts.
Is P0029 a VVT Code?
P0029 is frequently related to variable valve timing, but not on every engine.
On many vehicles, the Bank 2 exhaust valve control solenoid is effectively the exhaust VVT oil-control valve.
On other vehicles, P0029 may relate to:
- Variable valve lift
- Multi-stage exhaust-valve operation
- A hydraulic rocker-arm system
- Exhaust camshaft actuator feedback
- An actuator locking mechanism
- A manufacturer-specific valve-control system
This distinction matters because a replacement part advertised as a generic VVT solenoid may not be the correct component for every vehicle storing P0029.
Use vehicle-specific service information to confirm:
- Component terminology
- Component location
- Wiring configuration
- Resistance specifications
- Hydraulic operation
- Diagnostic procedures
How the Bank 2 Exhaust Valve Control System Works
A typical hydraulic exhaust camshaft-control system includes:
- ECM or PCM
- Bank 2 exhaust valve control solenoid
- Pressurized engine oil
- Exhaust camshaft phaser
- Exhaust camshaft position sensor
- Crankshaft position sensor
- Internal oil passages
The system generally operates as follows:
- The ECM calculates the desired Bank 2 exhaust camshaft or valve-control position.
- The ECM sends a duty-cycle command to the exhaust valve control solenoid.
- The solenoid redirects pressurized engine oil.
- Oil pressure moves the exhaust camshaft phaser or valve-control mechanism.
- A camshaft or actuator position sensor reports actual operation.
- The ECM compares commanded and actual values.
- The ECM adjusts the solenoid command as engine conditions change.
If the mechanism does not move correctly, responds too slowly or operates outside its electrical limits, the ECM may store P0029.
Why Exhaust Valve Control Matters
Changing exhaust valve timing or lift allows the engine to improve:
- Low-speed torque
- High-RPM airflow
- Combustion stability
- Fuel economy
- Exhaust emissions
- Internal exhaust-gas recirculation
- Turbocharger response
- Catalyst warm-up
- Engine braking characteristics
- Cylinder scavenging
When the Bank 2 exhaust valve-control system fails, one side of the engine may operate differently from the other.
This can create:
- Uneven exhaust flow
- Bank-to-bank fuel-trim differences
- Rough idle
- Reduced power
- Misfires
- Increased emissions
- Uneven turbocharger response on some engines
How the ECM Detects P0029
The exact P0029 detection strategy varies by manufacturer.
The ECM may monitor:
- Solenoid circuit voltage
- Solenoid current draw
- Coil resistance
- Commanded duty cycle
- Actual Bank 2 exhaust camshaft position
- Actuator position feedback
- Camshaft response time
- Crankshaft-to-camshaft correlation
- Engine-oil temperature
- Engine speed
- Engine load
- Battery voltage
P0029 may be stored when:
- The solenoid draws abnormal current.
- The actuator does not move when commanded.
- Exhaust camshaft movement is too slow.
- The mechanism remains stuck.
- Commanded and actual positions differ excessively.
- The actuator operates outside its calibrated range.
- The system cannot complete a self-test.
- The circuit behaves intermittently.
- Bank 2 operation differs significantly from Bank 1.
The code may set during:
- Cold startup
- Warm idle
- Acceleration
- Deceleration
- Highway cruising
- Engine braking
- A manufacturer-specific actuator test
Symptoms of the P0029 Code
Symptoms vary depending on the vehicle and the design of its exhaust valve-control system.
Common P0029 symptoms include:
- Illuminated Check Engine Light
- Rough idle
- Poor acceleration
- Reduced engine power
- Engine hesitation
- Weak low-RPM torque
- Reduced high-RPM performance
- Poor fuel economy
- Hard starting
- Extended cranking
- Engine stalling
- Engine misfires
- Uneven engine operation
- Increased exhaust emissions
- Strong exhaust odor
- Backfiring through the exhaust
- Limp mode
- Failed emissions inspection
- Reduced turbocharger response
- Timing-chain or camshaft-actuator rattle
- Bank-to-bank fuel-trim imbalance
Some vehicles may show no noticeable symptoms beyond the Check Engine Light.
The ECM may disable Bank 2 exhaust VVT or valve-lift control and operate the engine using a fixed default position.
Common Causes of P0029
1. Dirty Engine Oil
Dirty engine oil is one of the most common causes of hydraulic exhaust valve-control problems.
Contaminated oil can create:
- Sludge
- Varnish
- Carbon deposits
- Restricted oil passages
- Sticking solenoid valves
- Slow actuator response
- Clogged filter screens
Exhaust valve-control systems often depend on narrow oil passages and precise hydraulic pressure.
Contamination may prevent the Bank 2 actuator from reaching its commanded position.
2. Incorrect Engine-Oil Viscosity
Oil that is too thick or too thin can interfere with exhaust actuator operation.
Oil that is too thick may:
- Flow slowly during cold starts
- Delay VVT response
- Restrict small oil passages
- Prevent rapid actuator movement
- Cause sluggish performance in cold weather
Oil that is too thin may:
- Leak through worn internal clearances
- Reduce hydraulic pressure
- Cause unstable actuator control
- Prevent the mechanism from holding position
- Increase hot-idle control problems
Use the manufacturer-specified oil viscosity and oil standard.
3. Low Engine-Oil Level
Low engine oil reduces the hydraulic reserve available to the Bank 2 exhaust valve-control system.
Possible causes include:
- External oil leaks
- Excessive oil consumption
- Improper servicing
- Extended oil-change intervals
- Internal engine wear
Always check the engine-oil level before replacing electrical components.
4. Overfilled Engine Oil
An overfilled crankcase may allow the crankshaft to whip air into the engine oil.
Aerated oil may cause:
- Unstable hydraulic pressure
- Delayed actuator response
- Erratic camshaft movement
- Oil foaming
- Reduced lubrication quality
Correct an overfilled crankcase before continuing diagnosis.
5. Low Engine-Oil Pressure
The crankcase may contain the correct amount of oil while actual oil pressure remains too low.
Possible causes include:
- Worn oil pump
- Restricted oil pickup
- Excessive bearing clearance
- Internal oil leakage
- Failed oil-pressure control valve
- Damaged oil-pump drive
- Aerated oil
- Clogged oil galleries
Low oil pressure may affect:
- Exhaust valve-control solenoids
- Camshaft phasers
- Variable valve-lift mechanisms
- Timing-chain tensioners
A mechanical oil-pressure test may be required.
6. Sticking Bank 2 Exhaust Valve Control Solenoid
The solenoid may stick because of:
- Sludge
- Varnish
- Metal particles
- Internal wear
- A damaged spool valve
- A weak return spring
- Oil contamination
A sticking solenoid may move slowly, remain trapped in one position or fail to direct enough oil to the exhaust camshaft actuator.
It may still pass a basic electrical resistance test.
7. Failed Solenoid Coil
The solenoid contains an electrical coil that moves its internal valve.
The coil may fail because of:
- Internal open circuit
- Shorted windings
- Excessive resistance
- Heat damage
- Oil intrusion
- Manufacturing defects
- Age-related deterioration
A partially failed coil may continue operating while drawing current outside the ECM’s expected range.
This can trigger a range/performance code without setting a straightforward circuit-open code.
8. Clogged Solenoid Filter Screen
Some exhaust valve-control solenoids contain a fine filter screen.
The screen may become restricted by:
- Sludge
- Carbon deposits
- Metal particles
- Silicone sealant
- Gasket material
- Oil-filter debris
- Internal engine wear particles
A clogged screen may reduce oil flow and slow actuator movement.
9. Restricted Oil Passages
Oil galleries in the cylinder head, camshaft bearing cap or actuator housing may become restricted.
Possible causes include:
- Sludge
- Varnish
- Metal debris
- Excessive sealant
- Damaged gasket
- Improper engine assembly
- Previous engine repairs
- Carbon contamination
A restricted passage may prevent the Bank 2 exhaust actuator from reaching its requested position.
10. Damaged Wiring Harness
The Bank 2 exhaust solenoid wiring may be damaged by:
- Engine heat
- Exhaust heat
- Vibration
- Oil exposure
- Harness abrasion
- Sharp brackets
- Rodents
- Incorrect routing
- Previous repairs
Common trouble areas include:
- Near the valve cover
- Around the timing cover
- Near the exhaust manifold
- Beneath engine covers
- At tight harness bends
- Near connector strain points
Intermittent wiring faults may appear only when the engine is hot, vibrating or moving under load.
11. Loose or Corroded Connector
A poor connector connection may create excessive resistance or intermittent operation.
Inspect for:
- Green or white corrosion
- Bent terminals
- Backed-out pins
- Loose terminal tension
- Broken locking tabs
- Oil contamination
- Water intrusion
- Damaged connector seals
A connector may appear attached while its terminals fail to maintain reliable contact.
12. Oil Inside the Electrical Connector
Engine oil may enter the solenoid connector through:
- A leaking solenoid body
- Damaged solenoid seals
- A valve-cover leak
- Oil migration through wiring insulation
- Improper previous repair
Oil contamination can interfere with terminal contact and attract dirt.
Repair the source of the oil leak instead of cleaning the connector and pretending the problem has developed manners.
13. Short to Ground or Voltage
The control circuit may become shorted because of:
- Chafed insulation
- Melted wiring
- A pinched harness
- Incorrect splice repair
- Water intrusion
- Aftermarket electrical modifications
A short may cause:
- Abnormal current draw
- Continuous solenoid activation
- ECM driver shutdown
- Repeated fuse failure
- Immediate code reset
14. Excessive Circuit Resistance
The circuit may remain connected but have too much resistance under load.
Possible causes include:
- Corroded terminals
- Partially broken wire strands
- Weak connector contact
- Poor splices
- Heat-damaged wiring
- Internal solenoid resistance
Voltage-drop testing is generally more useful than a simple continuity test for finding high resistance.
15. Failed Bank 2 Exhaust Camshaft Phaser
A failed exhaust camshaft phaser may cause the system to operate outside its expected range.
Possible failures include:
- Internal oil leakage
- Sticking rotor
- Failed locking pin
- Worn internal vanes
- Broken internal stop
- Excessive mechanical play
- Cracked actuator housing
- Damaged return mechanism
The ECM may correctly command the solenoid while the phaser fails to move.
16. Failed Variable Valve-Lift Mechanism
On engines using variable exhaust valve lift, the problem may involve:
- Stuck locking pins
- Damaged rocker arms
- Worn followers
- Broken springs
- Sludge-filled oil galleries
- Mechanical binding
- Incorrect assembly
- A failed valve-control actuator
Diagnosis may require removing the valve cover or partially disassembling the cylinder head.
17. Mechanical Timing Problem
P0029 may occur when the Bank 2 exhaust camshaft cannot reach its expected position because of:
- Stretched timing chain
- Jumped timing chain
- Failed chain tensioner
- Broken timing guide
- Damaged timing-belt teeth
- Incorrect camshaft timing
- Improper phaser installation
- A loose camshaft sprocket
Related symptoms may include:
- Startup rattle
- Extended cranking
- Misfires
- Poor compression
- Correlation codes
- A no-start condition
18. Incorrect Mechanical Timing After Repair
If P0029 appears after engine work, possible causes include:
- Bank 2 exhaust camshaft installed one tooth off
- Incorrect timing-mark alignment
- Wrong colored-chain-link placement
- Camshaft phaser installed incorrectly
- Timing tensioner released improperly
- Incorrect camshaft locking procedure
- Wrong replacement sprocket or actuator
- Improperly torqued camshaft hardware
Verify mechanical timing before replacing additional parts.
19. Faulty Bank 2 Exhaust Camshaft Position Sensor
Some systems determine actuator performance by monitoring the Bank 2 exhaust camshaft position sensor.
A faulty sensor may produce:
- Weak signal
- Intermittent dropout
- Distorted waveform
- Incorrect timing data
- Heat-related failure
- Electrical noise
However, the sensor may be correctly reporting a real actuator or timing problem.
Do not replace it based on P0029 alone.
20. Faulty Valve-Control Position Sensor
Some variable valve-lift systems include a separate position sensor.
The sensor may fail because of:
- Internal wear
- Incorrect reference voltage
- Poor ground
- Signal-circuit damage
- Connector corrosion
- Mechanical misalignment
The ECM may store P0029 when actual actuator position does not match the commanded position.
21. Shifted Camshaft Reluctor Wheel
The camshaft position sensor reads a reluctor or trigger wheel attached to the camshaft or phaser.
The reluctor may become:
- Loose
- Bent
- Cracked
- Shifted
- Misaligned
- Damaged during previous repairs
A shifted reluctor may make the Bank 2 exhaust camshaft appear to be in the wrong position even when mechanical timing is correct.
22. Weak Battery or Charging-System Voltage
Low system voltage may interfere with solenoid control and ECM monitoring.
Possible causes include:
- Weak battery
- Failing alternator
- Loose battery terminals
- Poor engine ground
- Excessive cranking
- Charging-system malfunction
Check system voltage if several actuator, communication or voltage-related codes appear together.
23. Faulty ECM or PCM
ECM failure is uncommon but possible.
A failed internal driver may:
- Produce an incorrect duty cycle
- Fail to energize the solenoid
- Command the solenoid continuously
- Misread actuator feedback
- Shut down because of excessive current
Before replacing the ECM, verify:
- Solenoid resistance
- Power supply
- Wiring integrity
- Circuit voltage drop
- Ground condition
- Engine-oil pressure
- Mechanical actuator operation
24. Incorrect Replacement Component
An incorrect or poor-quality replacement part may cause P0029.
Examples include:
- Wrong exhaust valve control solenoid
- Incorrect camshaft phaser
- Nonmatching actuator
- Wrong valve-lift solenoid
- Incorrect camshaft sprocket
- Low-quality aftermarket part
A component may physically fit while having the wrong:
- Electrical resistance
- Connector pinout
- Oil-flow characteristics
- Mechanical travel
- Response speed
Is P0029 an Electrical or Mechanical Code?
P0029 is a range/performance code, so its cause may be electrical, hydraulic or mechanical.
Electrical causes include:
- Failed solenoid coil
- Open wiring
- Shorted wiring
- Excessive circuit resistance
- Poor connector contact
- Failed ECM driver
Hydraulic causes include:
- Dirty engine oil
- Low oil pressure
- Restricted oil passages
- Clogged solenoid screen
- Internal actuator leakage
Mechanical causes include:
- Stuck actuator
- Failed exhaust camshaft phaser
- Damaged variable valve-lift mechanism
- Incorrect timing
- Broken camshaft-sprocket components
A basic resistance test alone is not enough to rule out the solenoid or actuator.
How Serious Is the P0029 Code?
P0029 is generally considered moderately serious, but it can become severe when caused by a mechanical timing or camshaft-actuator failure.
Possible consequences include:
- Reduced engine performance
- Rough idle
- Poor fuel economy
- Increased emissions
- Engine misfires
- Catalytic converter damage
- Timing-chain wear
- Camshaft actuator failure
- Valvetrain damage
- Engine no-start
- Internal engine damage
The problem is more urgent if accompanied by:
- Timing-chain or actuator rattle
- Flashing Check Engine Light
- Severe misfires
- Low-oil-pressure warning
- P0019 or another correlation code
- Engine stalling
- Sudden power loss
- A no-start condition
Can You Drive With P0029?
Limited driving may be possible if:
- The engine runs smoothly.
- The Check Engine Light remains steady.
- No timing or valvetrain noise is present.
- The oil level is correct.
- No low-oil-pressure warning is displayed.
- The vehicle does not stall.
Continued driving is not recommended until the cause is identified.
Stop driving if:
- The Check Engine Light flashes.
- The engine misfires severely.
- Loud timing or camshaft noise is present.
- The oil-pressure warning appears.
- The engine stalls.
- Power drops suddenly.
- The engine cranks but will not start.
- Metallic debris is found in the oil.
A mechanical actuator or timing-system failure can become considerably more expensive if ignored.
How to Diagnose P0029
Step 1: Scan for Additional Codes
Use a capable OBD-II scanner to check for related codes.
Look for:
- P0019
- P0023
- P0024
- P0025
- P0026
- P0027
- P0028
- Camshaft position sensor codes
- Oil-pressure codes
- Misfire codes
- Battery-voltage codes
Record:
- Freeze-frame data
- Engine speed
- Engine load
- Coolant temperature
- Oil temperature
- Battery voltage
- Commanded actuator position
- Actual actuator position
- Solenoid duty cycle
- Exhaust camshaft timing data
Do not clear the codes before saving this information.
Step 2: Identify the Exact System
Determine what “exhaust valve control solenoid” means for the specific vehicle.
Use service information to identify:
- Bank 2
- Exhaust control solenoid
- Exhaust camshaft actuator
- Variable valve-lift mechanism
- Exhaust camshaft position sensor
- Actuator position sensor
- Connector pinout
- Power and control circuits
This step prevents testing or replacing the wrong component.
Step 3: Confirm Bank 2
Verify which side of the engine contains cylinder number one.
Bank 2 is the opposite cylinder bank.
Do not identify the bank solely by standing in front of the vehicle and guessing.
Use:
- Manufacturer service information
- Cylinder-numbering diagrams
- Firing-order diagrams
- Engine labels
Step 4: Check the Engine-Oil Level
Check the oil according to manufacturer instructions.
Look for:
- Low oil level
- Overfilled crankcase
- Fuel dilution
- Coolant contamination
- Metallic particles
- Sludge on the dipstick or oil cap
Correct the oil level before further diagnosis.
An overfilled crankcase may aerate the oil and cause unstable actuator operation.
Step 5: Inspect Oil Condition and Viscosity
Determine whether the oil is:
- Dirty
- Sludged
- Too thick
- Too thin
- Incorrect for the engine
- Overdue for replacement
- Contaminated with fuel or coolant
Perform an oil and filter change when necessary.
Use the exact manufacturer-specified viscosity and oil standard.
Step 6: Review Maintenance and Repair History
Determine:
- When the oil was last changed
- Whether the engine has been operated with low oil
- Whether timing work was recently performed
- Whether a valve cover or cylinder head was removed
- Whether the camshaft actuator was replaced
- Whether the engine rattles during startup
- Whether the problem began immediately after repair
Recent engine work may point toward incorrect installation, damaged wiring or incorrect mechanical timing.
Step 7: Perform a Visual Inspection
Inspect the Bank 2 exhaust valve-control system for:
- Broken wiring
- Chafed insulation
- Loose connectors
- Oil contamination
- Corrosion
- Bent terminals
- Heat damage
- Broken harness retainers
- Poor previous repairs
Move the harness gently while monitoring live data to identify intermittent faults.
Step 8: Inspect the Solenoid Connector
Disconnect the connector with the ignition off.
Inspect for:
- Bent pins
- Corrosion
- Oil intrusion
- Water contamination
- Backed-out terminals
- Loose terminal tension
- Broken locking tabs
- Damaged seals
Repair connector faults before replacing the solenoid.
Step 9: Measure Solenoid Resistance
Use a digital multimeter to measure resistance across the solenoid terminals.
Compare the result with manufacturer specifications.
Possible results include:
- Infinite resistance: Open solenoid coil
- Very low resistance: Shorted solenoid coil
- Out-of-range resistance: Damaged solenoid
- Correct resistance: Additional testing required
A solenoid may pass a resistance test and still stick mechanically.
Step 10: Verify Power and ECM Control
Check the circuit for:
- Correct power supply
- ECM control signal
- Good ground where applicable
- Short to voltage
- Short to ground
- Excessive circuit resistance
Use the exact wiring diagram for the vehicle.
Do not apply battery voltage directly to an ECM control terminal.
Step 11: Perform Voltage-Drop Testing
A wire may pass a continuity test while failing under load.
Perform voltage-drop tests across:
- Power-supply wire
- Control circuit
- Connector terminals
- Splices
- Ground connections
Excessive voltage drop indicates hidden circuit resistance.
Step 12: Command the Solenoid With a Scan Tool
Use a bidirectional scan tool when supported.
Command the Bank 2 exhaust valve-control system on and off or through its operating range.
Monitor:
- Commanded actuator position
- Actual actuator position
- Exhaust camshaft timing
- Solenoid duty cycle
- Solenoid current
- Engine idle quality
Possible results include:
- No electrical response: Failed solenoid, wiring fault or ECM driver problem
- Electrical response but no actuator movement: Stuck solenoid, restricted oil passage or failed actuator
- Slow movement: Dirty oil, low oil pressure or internal wear
- Erratic movement: Intermittent wiring, unstable oil pressure or sensor failure
- Camshaft moves but cannot hold position: Internal actuator leakage or poor oil pressure
Step 13: Remove and Inspect the Solenoid
Remove the Bank 2 exhaust valve control solenoid according to the service procedure.
Inspect for:
- Sludge
- Varnish
- Metal particles
- Clogged filter screens
- Damaged O-rings
- Sticking internal valve
- Physical damage
- Scored or worn surfaces
Clean or replace the component as appropriate.
Avoid harsh chemicals that may damage internal seals or protective coatings.
Step 14: Compare Bank 1 and Bank 2 Solenoids
If the Bank 1 and Bank 2 exhaust-control solenoids are identical, compare:
- Resistance
- Current draw
- Physical condition
- Scan-tool response
- Contamination
- Part numbers
Only swap components when:
- The part numbers match.
- The manufacturer permits it.
- Both components are clean.
- New seals are installed when required.
If the fault moves to Bank 1 and becomes P0027, the solenoid is likely defective.
Step 15: Compare Bank 1 and Bank 2 Scan Data
Monitor:
- Commanded Bank 1 exhaust camshaft position
- Actual Bank 1 exhaust camshaft position
- Commanded Bank 2 exhaust camshaft position
- Actual Bank 2 exhaust camshaft position
- Camshaft phase error
- Solenoid duty cycle
If Bank 1 responds correctly while Bank 2 does not, suspect a Bank 2-specific problem.
Possible causes include:
- Bank 2 exhaust-control solenoid
- Bank 2 wiring
- Bank 2 oil passage
- Bank 2 exhaust camshaft phaser
- Bank 2 camshaft position sensor
- Bank 2 mechanical timing
If both banks respond poorly, investigate:
- Incorrect engine oil
- Low engine-oil pressure
- Widespread sludge
- Shared power-supply problems
- ECM control faults
Step 16: Check Engine-Oil Pressure
Install a mechanical oil-pressure gauge if hydraulic performance is questionable.
Measure pressure at:
- Cold idle
- Warm idle
- Increased engine speed
Compare the readings with factory specifications.
Do not assume oil pressure is normal simply because the dashboard warning light remains off.
Step 17: Test the Bank 2 Exhaust Camshaft Position Sensor
Depending on sensor design, test:
- Reference voltage
- Ground
- Signal voltage
- Signal frequency
- Waveform quality
- Circuit continuity
An oscilloscope can identify:
- Signal dropout
- Electrical noise
- Incorrect timing relationship
- Reluctor damage
- Heat-related sensor failure
Step 18: Compare Camshaft and Crankshaft Waveforms
Use an oscilloscope to compare:
- Bank 2 exhaust camshaft signal
- Crankshaft position signal
- Bank 1 exhaust camshaft signal when useful
Compare the waveform with known-good data.
This may reveal:
- Timing-chain stretch
- Incorrect mechanical timing
- Shifted reluctor wheel
- Sensor dropout
- Excessive camshaft movement
- A camshaft that is mechanically stuck
Step 19: Inspect the Exhaust Camshaft Actuator or Valve-Lift Mechanism
If electrical and oil-pressure tests pass, inspect the mechanical system.
Look for:
- Stuck actuator
- Failed locking pin
- Broken internal stop
- Damaged rocker mechanism
- Worn camshaft phaser
- Excessive mechanical play
- Restricted oil galleries
- Damaged sprocket
Mechanical inspection may require removing the valve cover or timing cover.
Step 20: Verify Mechanical Timing
If correlation data or mechanical noise suggests a timing problem, verify:
- Crankshaft position
- Bank 2 exhaust camshaft alignment
- Timing-chain marks
- Timing-belt marks
- Chain tension
- Timing-guide condition
- Tensioner extension
- Camshaft-phaser position
- Sprocket condition
Use the manufacturer’s required locking tools and timing procedure.
Do not rotate an interference engine carelessly if the timing system may have jumped.
Step 21: Check Technical Service Bulletins
Search for service bulletins covering:
- P0029
- Bank 2 exhaust camshaft actuator failure
- Variable valve timing concerns
- Variable valve-lift problems
- Updated solenoid designs
- Oil-pressure problems
- Wiring-harness faults
- ECM software updates
- Revised oil specifications
A vehicle-specific bulletin may identify a known failure pattern and prevent unnecessary parts replacement.
Step 22: Verify the Repair
After completing repairs:
- Clear all stored codes.
- Start the engine from cold.
- Listen for timing or camshaft noise.
- Monitor commanded and actual actuator data.
- Command the system with a scan tool.
- Compare Bank 1 and Bank 2 response.
- Check for oil leaks.
- Complete the manufacturer’s drive cycle.
- Rescan for pending codes.
A successful repair should restore proper Bank 2 exhaust valve or camshaft control and prevent P0029 from returning.
Common P0029 Repairs and Costs
| Repair | Estimated cost |
| Diagnostic inspection | $100–$300 |
| Engine oil and filter change | $60–$180 |
| Clean solenoid or filter screen | $100–$250 |
| Repair electrical connector | $75–$300 |
| Repair wiring harness | $100–$600 |
| Replace Bank 2 exhaust valve control solenoid | $150–$600 |
| Replace exhaust camshaft position sensor | $150–$450 |
| Clean restricted oil passages | $200–$900 |
| Repair variable valve-lift mechanism | $500–$2,000+ |
| Replace Bank 2 exhaust camshaft actuator or phaser | $600–$2,000 |
| Replace camshaft sprocket | $700–$2,500 |
| Replace timing chain, guides and tensioner | $1,200–$4,000 |
| Repair internal engine damage | $2,500–$7,000+ |
| ECM software update | $100–$300 |
| Replace and program ECM | $1,000–$2,500+ |
Repair costs vary according to:
- Engine design
- Solenoid accessibility
- Whether the system controls timing or valve lift
- Required engine disassembly
- Local labor rates
- Whether mechanical timing damage is present
Common Diagnostic Mistakes
Assuming P0029 Always Means a Basic VVT Solenoid
P0029 may involve a conventional exhaust VVT system, a variable valve-lift mechanism or another manufacturer-specific design.
Identify the exact system before ordering parts.
Testing the Wrong Bank
P0029 applies to Bank 2.
Bank 2 is the side opposite cylinder number one.
Do not guess based on which side of the engine is easier to access.
Confusing P0029 With P0027
P0027 applies to the Bank 1 exhaust valve-control system.
P0029 applies to the Bank 2 exhaust valve-control system.
Confusing P0029 With P0023
P0023 primarily identifies an electrical fault in the Bank 2 exhaust camshaft actuator circuit.
P0029 is a range/performance code and may involve electrical, hydraulic or mechanical operation.
Replacing the Solenoid Without Checking the Oil
Dirty, low or incorrect oil may prevent the actuator from responding correctly.
Always inspect:
- Oil level
- Oil condition
- Oil viscosity
- Service history
Relying Only on Resistance Testing
A solenoid may have correct electrical resistance but still:
- Stick mechanically
- Have restricted oil flow
- Respond slowly
- Fail when hot
- Leak internally
Dynamic command testing may still be required.
Replacing the Camshaft Position Sensor First
The camshaft sensor may be correctly reporting a real actuator or timing problem.
Test the complete system before replacing it.
Ignoring Bank-to-Bank Comparison
Comparing Bank 1 and Bank 2 can reveal whether the fault is localized.
If both exhaust systems respond poorly, investigate:
- Oil-pressure problems
- Incorrect oil
- Shared electrical supply
- ECM issues
- Widespread sludge
Ignoring Timing or Camshaft Noise
Rattling may indicate:
- Camshaft phaser failure
- Timing-chain slack
- Failed tensioner
- Worn timing guides
- Damaged actuator hardware
A replacement solenoid will not repair mechanical damage.
Skipping Oil-Pressure Testing
The engine-oil level may be correct while pressure remains too low to operate the system.
Use a mechanical oil-pressure gauge when necessary.
Assuming an Oil Change Repairs Mechanical Damage
Fresh oil may help a contaminated solenoid.
It cannot repair:
- A failed camshaft phaser
- Broken valve-lift components
- A stretched timing chain
- A damaged sprocket
- Incorrect mechanical timing
Replacing the ECM Too Early
ECM failure is uncommon compared with:
- Dirty engine oil
- Solenoid failure
- Wiring faults
- Connector problems
- Low oil pressure
- Mechanical actuator failure
Verify the entire system before replacing the control module.
Vehicles Commonly Affected by P0029
P0029 may appear on vehicles using variable Bank 2 exhaust camshaft timing or exhaust-valve control.
Potentially affected manufacturers include:
- Subaru
- Volvo
- Ford
- Lincoln
- Jaguar
- Land Rover
- Hyundai
- Kia
- Nissan
- Infiniti
- Toyota
- Lexus
- Honda
- Acura
- BMW
- Mini
- Mercedes-Benz
- Volkswagen
- Audi
- Porsche
P0029 generally applies to engines with two cylinder banks, such as:
- V6 engines
- V8 engines
- V10 engines
- V12 engines
- Horizontally opposed engines
The precise meaning and repair procedure may differ among manufacturers.
One vehicle may use P0029 for a conventional exhaust oil-control solenoid, while another may associate it with a variable valve-lift or camshaft actuator mechanism.
Diagnosis must be based on the exact:
- Year
- Make
- Model
- Engine
- Wiring diagram
- Actuator design
- Maintenance history
- Repair history
How to Prevent P0029
Helpful preventive measures include:
- Check the engine-oil level regularly.
- Use the manufacturer-specified oil viscosity.
- Use oil that meets the required manufacturer standard.
- Change the oil and filter on schedule.
- Avoid extended oil-change intervals.
- Use a quality oil filter.
- Repair oil leaks promptly.
- Investigate excessive oil consumption.
- Address startup rattles immediately.
- Diagnose low-oil-pressure warnings promptly.
- Keep wiring away from hot exhaust components.
- Repair broken harness retainers.
- Use sealed automotive-grade wiring repairs.
- Avoid excessive gasket sealant near oil passages.
- Use the correct replacement solenoid or actuator.
- Verify mechanical timing after engine repairs.
- Review technical service bulletins before major repairs.
Clean oil and early attention to timing or valvetrain noise can prevent many exhaust valve-control failures.
Frequently Asked Questions About P0029
What does code P0029 mean?
P0029 means the Bank 2 exhaust valve control solenoid or related actuator system is operating outside its expected range or performance limits.
What is an exhaust valve control solenoid?
It is an ECM-controlled solenoid used to regulate exhaust camshaft timing, exhaust valve lift or another exhaust-valve-control function.
Is P0029 a VVT code?
Often, but not always.
Some manufacturers use P0029 for a variable camshaft timing system, while others may use it for a variable valve-lift or exhaust-actuator system.
Which side is Bank 2?
Bank 2 is the side of the engine that does not contain cylinder number one.
Its physical location varies by engine.
Is P0029 an electrical code?
P0029 is a range/performance code.
The underlying cause may be electrical, hydraulic or mechanical.
What is the difference between P0029 and P0027?
P0027 applies to the Bank 1 exhaust valve-control system.
P0029 applies to the Bank 2 exhaust valve-control system.
What is the difference between P0029 and P0023?
P0023 primarily indicates an electrical circuit fault affecting the Bank 2 exhaust camshaft actuator.
P0029 indicates that the Bank 2 exhaust valve-control system is operating outside its expected range or performance limits.
Can dirty oil cause P0029?
Yes. Dirty oil may clog the solenoid, filter screen, oil passages or exhaust camshaft actuator.
Can low oil cause P0029?
Yes. Low engine oil may reduce the hydraulic pressure needed to operate the exhaust valve-control system.
Can overfilled oil cause P0029?
Potentially.
An overfilled crankcase may aerate the oil and cause unstable hydraulic actuator operation.
Can the wrong oil viscosity cause P0029?
Yes. Incorrect oil viscosity can slow, weaken or destabilize actuator movement.
Can a bad VVT solenoid cause P0029?
Yes, on vehicles where the Bank 2 exhaust valve control solenoid is part of the VVT system.
Can damaged wiring cause P0029?
Yes. Broken wires, short circuits, connector corrosion and excessive resistance can trigger the code.
Can a bad exhaust camshaft phaser cause P0029?
Yes. A stuck, worn or internally leaking Bank 2 exhaust phaser may prevent the system from operating within range.
Can a stretched timing chain cause P0029?
Yes. Timing-chain wear may prevent the Bank 2 exhaust camshaft from reaching its expected position.
Can a bad camshaft sensor cause P0029?
Yes, but it is not always the most likely cause.
The sensor may be correctly reporting a real actuator or mechanical timing problem.
Can P0029 cause rough idle?
Yes. Incorrect Bank 2 exhaust camshaft timing or valve operation may cause rough idle, misfires and uneven combustion.
Can P0029 cause poor acceleration?
Yes. The engine may lose low-speed torque, high-RPM power or throttle response.
Can P0029 affect turbocharger response?
Yes. Incorrect exhaust camshaft timing may reduce exhaust energy available to the turbocharger on some engines.
Can P0029 cause fuel-trim problems?
Yes. If Bank 2 breathes differently from Bank 1, the two banks may develop different fuel-trim readings.
Can P0029 cause hard starting?
Yes. Incorrect exhaust valve or camshaft operation may cause extended cranking or hard starting.
Can P0029 cause engine damage?
Potentially.
A simple solenoid or circuit problem may not cause immediate damage, but a failed phaser, sprocket or timing system can become serious.
Can I drive with P0029?
Limited driving may be possible if the engine runs smoothly and makes no unusual noise.
Prompt diagnosis is recommended.
Will an oil change fix P0029?
It may help if the problem is caused by dirty or incorrect oil.
It will not repair damaged wiring, a failed solenoid coil, a broken actuator or an incorrect mechanical timing condition.
How much does it cost to fix P0029?
An oil service may cost under $200.
A solenoid replacement commonly costs $150 to $600.
Mechanical camshaft-actuator or timing repairs may cost $600 to $4,000 or more.
Will clearing P0029 fix the vehicle?
No. Clearing the code only removes the warning temporarily.
The code will return if the underlying problem remains.
Will P0029 fail an emissions test?
Yes. An active Check Engine Light or emissions-related powertrain code will generally cause an OBD-based emissions inspection failure.
Final Thoughts
The P0029 code means the Bank 2 exhaust valve control solenoid or related exhaust actuator system is operating outside its expected range.
The most common causes include:
- Dirty or incorrect engine oil
- Low engine-oil level
- Low oil pressure
- A sticking Bank 2 exhaust control solenoid
- A failed solenoid coil
- Restricted oil passages
- Damaged wiring or connectors
- A failed exhaust camshaft actuator
- A variable valve-lift system problem
- Incorrect mechanical timing
- A faulty position sensor
- An ECM control problem
Begin diagnosis by identifying exactly which component the manufacturer calls the exhaust valve control solenoid and confirming the physical location of Bank 2.
Check the engine-oil level, condition and viscosity before testing the electrical circuit. Inspect the wiring and connector, verify solenoid resistance, test power and control circuits and command the actuator with a bidirectional scan tool when possible.
Compare Bank 1 and Bank 2 operation whenever live data is available. A properly functioning Bank 1 system can provide an excellent reference for identifying a Bank 2-specific failure.
If the electrical circuit functions correctly but the actuator does not move as commanded, inspect:
- Engine-oil pressure
- VVT oil passages
- The exhaust camshaft phaser
- The variable valve-lift mechanism
- Mechanical camshaft timing
P0029 may be caused by something as simple as contaminated oil or as serious as a damaged camshaft actuator or timing chain. Proper testing is cheaper than replacing every solenoid near the valve cover and hoping one of them persuades the Check Engine Light to leave.
For more diagnostic guides, browse our growing OBD-II libraries:
- Complete OBD-II Code Library: https://my.prostreetonline.com/dtc-obdii/
- Body (B) Codes: https://my.prostreetonline.com/dtc-doctor/b-code-obd-ii-codes/
- Chassis (C) Codes: https://my.prostreetonline.com/dtc-doctor/c-code-obd-ii-codes/
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