If your OBD-II scanner displays P0028, your vehicle’s Engine Control Module (ECM) or Powertrain Control Module (PCM) has detected that the Bank 2 intake valve control solenoid circuit or intake camshaft control system is not operating within its expected range.
The generic description for P0028 is:
Intake Valve Control Solenoid Circuit Range/Performance Bank 2
Depending on the manufacturer, the affected component may also be called the:
- Intake valve control solenoid
- Intake valve timing control solenoid
- Intake VVT solenoid
- Oil control valve
- Intake camshaft actuator
- Camshaft timing control valve
- Variable camshaft timing solenoid
- Variable valve-lift control solenoid
P0028 is a range/performance code. This means the ECM may still be able to energize or communicate with the solenoid, but the Bank 2 intake valve-control system does not respond as expected.
The underlying problem may be:
- Electrical
- Hydraulic
- Mechanical
- Sensor-related
- Software-related
Common causes include:
- Dirty or incorrect engine oil
- Low engine-oil level
- Low oil pressure
- A sticking Bank 2 intake valve control solenoid
- A failed solenoid coil
- Restricted oil passages
- A clogged solenoid filter screen
- Damaged wiring or connectors
- A failed intake camshaft phaser
- A variable valve-lift mechanism fault
- Incorrect mechanical timing
- A faulty camshaft or actuator position sensor
- An ECM software or driver problem
P0028 should be diagnosed promptly. Some vehicles may continue running with only a Check Engine Light, but the ECM may disable Bank 2 intake variable valve timing or valve-lift operation. This can cause rough idle, poor acceleration, reduced fuel economy, increased emissions and 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/
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- Chassis (C) Codes: https://my.prostreetonline.com/dtc-doctor/c-code-obd-ii-codes/
P0028 Quick Facts
| Item | Information |
|---|---|
| OBD-II code | P0028 |
| Official description | Intake Valve Control Solenoid Circuit Range/Performance Bank 2 |
| Category | Powertrain |
| System | Intake 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 P0028 Code Mean?
P0028 means the ECM has detected that the Bank 2 intake valve control solenoid or related intake camshaft-control system is operating outside its expected electrical or mechanical range.
A range/performance code differs from a straightforward open-circuit or short-circuit code.
The ECM may detect that:
- Solenoid current is too high or too low.
- Circuit resistance is outside specification.
- The actuator does not move when commanded.
- The Bank 2 intake camshaft does not reach its requested position.
- The valve-control mechanism moves too slowly.
- The system 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 works electrically but performs poorly mechanically.
P0028 may therefore indicate:
- A failed solenoid
- A wiring or connector fault
- Poor oil flow
- A failed camshaft actuator
- A valve-lift system problem
- Incorrect camshaft timing
- A faulty feedback sensor
- An ECM control problem
Related trouble codes include:
- P0020: “A” Camshaft Position Actuator Circuit Bank 2
- P0021: “A” Camshaft Position Timing Over-Advanced Bank 2
- P0022: “A” Camshaft Position Timing Over-Retarded Bank 2
- P0018: Crankshaft Position–Camshaft Position Correlation Bank 2 Sensor A
- P0026: Intake Valve Control Solenoid Circuit Range/Performance Bank 1
- P0027: Exhaust Valve Control Solenoid Circuit Range/Performance Bank 1
- P0029: Exhaust 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 normally have only Bank 1 and should not store a true Bank 2 intake valve-control code.
Bank 2 may be located on either side of the vehicle depending on the manufacturer and 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 on the driver side or passenger side.
What Is an Intake Valve Control Solenoid?
The intake valve control solenoid is an electronically controlled actuator used to alter some aspect of intake-valve or intake-camshaft operation.
Depending on the engine, it may control:
- Intake camshaft timing
- Oil flow to an intake camshaft phaser
- Intake valve lift
- Intake valve duration
- A multi-stage rocker-arm mechanism
- Camshaft actuator locking and release
- Cylinder deactivation-related valve operation on some designs
The ECM commonly operates the solenoid using a pulse-width-modulated electrical signal.
On a hydraulic VVT system, the solenoid redirects pressurized engine oil to different chambers inside the intake camshaft phaser.
On a variable valve-lift system, the solenoid may direct oil pressure to rocker arms, locking pins or another valvetrain mechanism.
Manufacturer terminology varies, so identify the exact component before testing or replacement.
Is P0028 a VVT Code?
P0028 is often related to variable valve timing, but not on every engine.
On many vehicles, the Bank 2 intake valve control solenoid is effectively the intake VVT oil-control valve.
On other engines, P0028 may relate to:
- Variable valve lift
- Multi-stage intake-valve operation
- A hydraulic rocker-arm control system
- Intake camshaft actuator feedback
- An actuator locking mechanism
- A manufacturer-specific valve-control system
This distinction matters because a generic replacement “VVT solenoid” may not be the correct component for every vehicle storing P0028.
How the Bank 2 Intake Valve Control System Works
A typical hydraulic intake camshaft-control system includes:
- ECM or PCM
- Bank 2 intake valve control solenoid
- Pressurized engine oil
- Intake camshaft phaser
- Intake camshaft position sensor
- Crankshaft position sensor
- Internal oil passages
The system generally operates as follows:
- The ECM calculates the desired Bank 2 intake camshaft or valve-control position.
- The ECM sends a duty-cycle command to the intake valve control solenoid.
- The solenoid redirects pressurized engine oil.
- Oil pressure moves the intake camshaft phaser or valve-control mechanism.
- A position sensor reports actual operation.
- The ECM compares commanded and actual values.
- The ECM adjusts the solenoid command as operating conditions change.
If the system does not move correctly or its electrical characteristics fall outside the expected range, the ECM stores P0028.
Why Intake Valve Control Matters
Adjusting intake valve operation allows the engine to improve:
- Low-speed torque
- High-RPM airflow
- Fuel economy
- Throttle response
- Cold-start performance
- Combustion stability
- Exhaust emissions
- Internal exhaust-gas recirculation
- Turbocharger response on some engines
When the Bank 2 intake valve-control system fails, one side of the engine may operate differently from the other.
This can create:
- Uneven cylinder filling
- Bank-to-bank fuel-trim differences
- Rough idle
- Reduced power
- Misfires
- Increased emissions
How the ECM Detects P0028
The exact detection strategy varies by manufacturer.
The ECM may monitor:
- Solenoid circuit voltage
- Solenoid current draw
- Coil resistance
- Commanded duty cycle
- Actual Bank 2 intake camshaft position
- Actuator position feedback
- Camshaft response time
- Crankshaft-to-camshaft correlation
- Oil temperature
- Engine speed
- Engine load
P0028 may be stored when:
- The solenoid draws abnormal current.
- The actuator does not move when commanded.
- Intake camshaft movement is too slow.
- The mechanism remains stuck.
- Commanded and actual positions differ too much.
- The actuator operates outside a calibrated range.
- The system cannot complete a self-test.
- The circuit operates intermittently.
The code may set during:
- Cold startup
- Warm idle
- Acceleration
- Deceleration
- Highway cruising
- A manufacturer-specific actuator test
Symptoms of the P0028 Code
Symptoms vary depending on the vehicle and the type of intake valve-control system.
Common 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
- Limp mode
- Failed emissions inspection
- Reduced throttle 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 intake VVT or valve-lift control and operate the engine in a default position.
Common Causes of P0028
1. Dirty Engine Oil
Dirty engine oil is one of the most common causes of hydraulic intake valve-control problems.
Contaminated oil can create:
- Sludge
- Varnish
- Carbon deposits
- Restricted oil passages
- Sticking solenoid valves
- Slow actuator response
- Clogged filter screens
Intake valve-control systems often depend on small oil passages and precise hydraulic pressure.
Contamination may prevent the Bank 2 actuator from reaching its commanded position.
2. Incorrect Oil Viscosity
Oil that is too thick or too thin can interfere with intake actuator operation.
Oil that is too thick may:
- Flow slowly during cold starts
- Delay VVT response
- Restrict small oil passages
- Prevent rapid actuator movement
Oil that is too thin may:
- Leak through worn internal clearances
- Reduce hydraulic pressure
- Cause unstable actuator control
- Prevent the mechanism from holding position
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 intake valve-control system.
Possible causes include:
- External oil leaks
- Excessive oil consumption
- Improper servicing
- Extended oil-change intervals
- Internal engine wear
Always check the oil level before replacing electrical components.
4. Overfilled Engine Oil
An overfilled crankcase may allow the crankshaft to aerate the oil.
Aerated oil contains air bubbles and may cause:
- Unstable hydraulic pressure
- Delayed actuator response
- Erratic camshaft movement
- 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 pressure remains too low.
Possible causes include:
- Worn oil pump
- Restricted oil pickup
- Excessive bearing clearance
- Internal oil leakage
- Failed pressure-control valve
- Damaged oil-pump drive
- Aerated oil
- Clogged oil galleries
Low oil pressure may affect:
- Intake valve-control solenoids
- Camshaft phasers
- Variable valve-lift mechanisms
- Timing-chain tensioners
A mechanical oil-pressure test may be required.
6. Sticking Bank 2 Intake 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 actuator.
It may still pass an 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 defect
A partially failed coil may continue operating while drawing current outside the ECM’s expected range.
8. Clogged Solenoid Filter Screen
Some intake-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
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
A restricted passage may prevent the Bank 2 intake actuator from reaching its requested position.
10. Damaged Wiring Harness
The Bank 2 intake solenoid wiring may be damaged by:
- Engine 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
- Under intake components
- Near exhaust heat shields
- At tight harness bends
- Near connector strain points
Intermittent faults may appear only when the engine is hot or moving.
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 seals
A connector may appear attached while its terminals fail to make reliable contact.
12. Oil Inside the Connector
Engine oil may enter the solenoid connector through:
- A leaking solenoid body
- Damaged seals
- A valve-cover leak
- Oil migration through wiring insulation
Oil contamination can interfere with terminal contact and attract dirt.
Repair the source of the oil leak instead of cleaning the connector alone.
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 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 more useful than a simple continuity test for locating high resistance.
15. Failed Bank 2 Intake Camshaft Phaser
A failed intake 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
The ECM may correctly command the solenoid while the phaser fails to move.
16. Failed Variable Valve-Lift Mechanism
On engines using variable 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 valve-cover removal or partial cylinder-head disassembly.
17. Mechanical Timing Problem
P0028 may occur when the Bank 2 intake 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
Related symptoms may include:
- Startup rattle
- Extended cranking
- Misfires
- Poor compression
- Correlation codes
- No-start condition
18. Incorrect Mechanical Timing After Repair
If P0028 appears after engine work, possible causes include:
- Bank 2 intake 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
Verify mechanical timing before replacing additional parts.
19. Faulty Bank 2 Intake Camshaft Position Sensor
Some systems determine actuator performance by monitoring the intake camshaft position sensor.
A faulty sensor may produce:
- Weak signal
- Intermittent dropout
- Distorted waveform
- Incorrect timing data
- Heat-related failure
- Signal noise
However, the sensor may be correctly reporting a real actuator or timing problem.
Do not replace it based on P0028 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 set P0028 when actual actuator position does not match the command.
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 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 fault
Check system voltage if several actuator 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 it 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
- Oil pressure
- Mechanical actuator operation
24. Incorrect Replacement Component
An incorrect or poor-quality replacement part may cause P0028.
Examples include:
- Wrong intake 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 resistance, oil-flow characteristics or mechanical travel.
Is P0028 an Electrical or Mechanical Code?
P0028 is a range/performance code, so the cause may be electrical, hydraulic or mechanical.
Electrical causes include:
- Failed solenoid coil
- Open wiring
- Shorted wiring
- Excessive resistance
- Poor connector contact
- Failed ECM driver
Hydraulic causes include:
- Dirty engine oil
- Low oil pressure
- Restricted oil passages
- Clogged filter screen
- Internal actuator leakage
Mechanical causes include:
- Stuck actuator
- Failed intake 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 P0028 Code?
P0028 is generally considered moderately serious, but it can become severe when caused by a mechanical timing or camshaft-actuator failure.
Possible consequences include:
- Reduced 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
- P0018 or another correlation code
- Engine stalling
- Sudden power loss
- A no-start condition
Can You Drive With P0028?
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.
A mechanical actuator or timing-system failure can become much more expensive if ignored.
How to Diagnose P0028
Step 1: Scan for Additional Codes
Use a capable OBD-II scanner to check for related codes.
Look for:
- P0018
- P0020
- P0021
- P0022
- P0026
- P0027
- P0029
- 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
- Intake camshaft timing data
Do not clear the codes before saving this information.
Step 2: Identify the Exact System
Determine what “intake valve control solenoid” means for the specific vehicle.
Use service information to identify:
- Bank 2
- Intake control solenoid
- Intake camshaft actuator
- Variable valve-lift mechanism
- Intake 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 side.
Do not identify the bank only by looking at the vehicle from the front.
Use:
- 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
Correct the 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
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 run low on oil
- Whether timing work was recently performed
- Whether the 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 work may point toward incorrect installation or mechanical timing.
Step 7: Perform a Visual Inspection
Inspect the Bank 2 intake 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 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 Ground
Check the circuit for:
- Correct power supply
- ECM control signal
- Good ground
- Short to voltage
- Short to ground
- Excessive resistance
Use the exact wiring diagram.
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 resistance.
Step 12: Command the Solenoid With a Scan Tool
Use a bidirectional scan tool when supported.
Command the Bank 2 intake valve-control system on and off or through its operating range.
Monitor:
- Commanded actuator position
- Actual actuator position
- Intake 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 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
Step 13: Remove and Inspect the Solenoid
Remove the Bank 2 intake 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
Clean or replace the component as appropriate.
Avoid harsh chemicals that may damage seals or internal coatings.
Step 14: Compare Bank 1 and Bank 2 Solenoids
If the Bank 1 and Bank 2 intake-control solenoids are identical, compare:
- Resistance
- Current draw
- Physical condition
- Scan-tool response
- Contamination
Only swap components when:
- Part numbers match.
- The manufacturer permits it.
- Both components are clean.
- New seals are installed when required.
If the code moves to Bank 1 and becomes P0026, the solenoid is likely defective.
Step 15: Compare Bank 1 and Bank 2 Scan Data
Monitor:
- Commanded Bank 1 intake camshaft position
- Actual Bank 1 intake camshaft position
- Commanded Bank 2 intake camshaft position
- Actual Bank 2 intake 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 intake-control solenoid
- Bank 2 wiring
- Bank 2 oil passage
- Bank 2 intake camshaft phaser
- Bank 2 camshaft position sensor
- Bank 2 mechanical timing
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 readings with factory specifications.
Do not assume pressure is normal because the dashboard warning light remains off.
Step 17: Test the Bank 2 Intake 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
- Noise
- Incorrect timing relationship
- Reluctor damage
- Heat-related sensor failure
Step 18: Compare Camshaft and Crankshaft Waveforms
Use an oscilloscope to compare:
- Bank 2 intake camshaft signal
- Crankshaft position signal
- Bank 1 intake 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
Step 19: Inspect the Intake 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 play
- Restricted oil galleries
- Damaged sprocket
Mechanical inspection may require valve-cover or timing-cover removal.
Step 20: Verify Mechanical Timing
If correlation data or mechanical noise suggests a timing problem, verify:
- Crankshaft position
- Bank 2 intake 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.
Step 21: Check Technical Service Bulletins
Search for service bulletins covering:
- P0028
- Bank 2 intake camshaft actuator failure
- Variable valve timing concerns
- Variable valve-lift problems
- Updated solenoid designs
- Oil-pressure concerns
- 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 required drive cycle.
- Rescan for pending codes.
A successful repair should restore proper Bank 2 intake valve or camshaft control and prevent P0028 from returning.
Common P0028 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 intake valve control solenoid | $150–$600 |
| Replace intake camshaft position sensor | $150–$450 |
| Clean restricted oil passages | $200–$900 |
| Repair variable valve-lift mechanism | $500–$2,000+ |
| Replace Bank 2 intake camshaft actuator or phaser | $600–$2,000 |
| Replace camshaft sprocket | $700–$2,500 |
| Replace timing chain, guides and tensioner | $1,200–$4,000 |
| 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
- Labor rates
- Whether mechanical timing damage is present
Common Diagnostic Mistakes
Assuming P0028 Always Means a Basic VVT Solenoid
P0028 may involve a conventional intake VVT system, a variable valve-lift mechanism or another manufacturer-specific design.
Identify the system before ordering parts.
Testing the Wrong Bank
P0028 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 reach.
Confusing P0028 With P0026
P0026 applies to the Bank 1 intake valve-control system.
P0028 applies to the Bank 2 intake valve-control system.
Replacing the Solenoid Without Checking the Oil
Dirty, low or incorrect oil may prevent the actuator from responding correctly.
Always inspect the oil level, condition and viscosity first.
Relying Only on Resistance Testing
A solenoid may have correct resistance but still:
- Stick mechanically
- Have restricted oil flow
- Respond slowly
- Fail when hot
Dynamic command testing may still be necessary.
Confusing P0028 With P0020
P0020 primarily indicates an electrical fault in the Bank 2 intake camshaft actuator circuit.
P0028 is a range/performance code and may involve electrical, hydraulic or mechanical operation.
Replacing the Camshaft Position Sensor First
The 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 problem is localized.
If both banks respond poorly, suspect:
- Oil-pressure problems
- Incorrect oil
- Shared electrical supply
- ECM issue
- Widespread sludge
Ignoring Timing or Camshaft Noise
Rattling may indicate:
- Camshaft phaser failure
- Timing-chain slack
- Failed tensioner
- Worn guides
- Damaged actuator hardware
A replacement solenoid will not repair a mechanical failure.
Skipping Oil-Pressure Testing
The oil level may be correct while pressure remains too low to operate the system.
Use a mechanical pressure gauge when necessary.
Assuming an Oil Change Repairs Mechanical Damage
Fresh oil may help a contaminated solenoid.
It cannot repair:
- A failed phaser
- Broken valve-lift components
- Stretched timing chain
- Damaged sprocket
- Incorrect mechanical timing
Replacing the ECM Too Early
ECM failure is uncommon compared with:
- Dirty oil
- Solenoid failure
- Wiring faults
- Connector problems
- Low oil pressure
- Mechanical actuator failure
Verify the complete system before replacing the module.
Vehicles Commonly Affected by P0028
P0028 may appear on vehicles using variable Bank 2 intake camshaft timing or intake-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
P0028 generally applies to engines with two cylinder banks, such as:
- V6 engines
- V8 engines
- V10 engines
- V12 engines
- Horizontally opposed engines
The meaning and repair procedure may differ among manufacturers.
One vehicle may use P0028 for a conventional intake 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 P0028
Helpful preventive measures include:
- Check the engine-oil level regularly.
- Use the manufacturer-specified oil viscosity.
- 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 engine 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 service bulletins before major repairs.
Clean oil and early attention to timing or valvetrain noise can prevent many intake valve-control failures.
Frequently Asked Questions About P0028
What does code P0028 mean?
P0028 means the Bank 2 intake valve control solenoid or related actuator system is operating outside its expected range or performance limits.
What is an intake valve control solenoid?
It is an ECM-controlled solenoid used to regulate intake camshaft timing, intake valve lift or another intake-valve-control function.
Is P0028 a VVT code?
Often, but not always.
Some manufacturers use P0028 for a variable camshaft timing system, while others may use it for a variable valve-lift or intake-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 P0028 an electrical code?
It is a range/performance code.
The cause may be electrical, hydraulic or mechanical.
Can dirty oil cause P0028?
Yes. Dirty oil may clog the solenoid, filter screen, oil passages or actuator.
Can low oil cause P0028?
Yes. Low oil may reduce the hydraulic pressure required for proper operation.
Can overfilled oil cause P0028?
Potentially.
An overfilled engine may aerate the oil and cause unstable hydraulic actuator operation.
Can the wrong oil viscosity cause P0028?
Yes. Incorrect viscosity can slow or destabilize actuator movement.
Can a bad VVT solenoid cause P0028?
Yes, on vehicles where the Bank 2 intake valve control solenoid is part of the VVT system.
Can damaged wiring cause P0028?
Yes. Broken wires, shorts, connector corrosion and excessive resistance can trigger the code.
Can a bad intake camshaft phaser cause P0028?
Yes. A stuck, worn or internally leaking Bank 2 intake phaser may prevent the system from operating within range.
Can a stretched timing chain cause P0028?
Yes. Timing-chain wear may prevent the Bank 2 intake camshaft from reaching its expected position.
Can a bad camshaft sensor cause P0028?
Yes, but it is not always the most likely cause.
The sensor may be correctly reporting an actuator problem.
Can P0028 cause rough idle?
Yes. Incorrect Bank 2 intake camshaft timing or valve operation may cause rough idle, misfires and uneven combustion.
Can P0028 cause poor acceleration?
Yes. The engine may lose low-speed torque, high-RPM power or throttle response.
Can P0028 cause fuel-trim problems?
Yes. If Bank 2 fills its cylinders differently from Bank 1, fuel trims may differ significantly between the two banks.
Can P0028 cause hard starting?
Yes. Incorrect intake valve or camshaft operation may cause extended cranking or hard starting.
Can P0028 cause engine damage?
Potentially.
A simple circuit or solenoid problem may not cause immediate damage, but a failed phaser, sprocket or timing system can become serious.
Can I drive with P0028?
Limited driving may be possible if the engine runs smoothly and makes no unusual noise.
Prompt diagnosis is recommended.
Will an oil change fix P0028?
It may help if the problem is caused by dirty or incorrect oil.
It will not repair damaged wiring, a failed solenoid coil, broken actuator or mechanical timing problem.
How much does it cost to fix P0028?
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 P0028 fix the vehicle?
No. Clearing the code only removes the warning temporarily.
The code will return if the underlying problem remains.
Will P0028 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 P0028 code means the Bank 2 intake valve control solenoid or related intake 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 intake control solenoid
- A failed solenoid coil
- Restricted oil passages
- Damaged wiring or connectors
- A failed intake 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 system the manufacturer calls the intake valve control solenoid and confirming the physical location of Bank 2.
Check the 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 scan data is available. A healthy Bank 1 system can provide a useful reference for identifying a Bank 2-specific failure.
If the electrical circuit works but the actuator does not move correctly, inspect oil pressure, oil passages, the intake camshaft phaser, valve-lift mechanism and mechanical timing.
P0028 may be caused by something as simple as contaminated oil or as serious as a damaged camshaft actuator. Proper testing is cheaper than replacing every solenoid within arm’s reach and hoping the Check Engine Light gets bored.
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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- P0026 Code Explained: Intake Valve Control Solenoid Circuit Range/Performance Bank 1
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