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P0319 Code: Rough Road Sensor “B” Signal Circuit

P0319 Rough Road Sensor B signal circuit diagnostic guide

The P0319 OBD-II trouble code means the powertrain control module has detected a problem with its designated Rough Road Sensor “B” signal.

The generic definition is:

P0319 — Rough Road Sensor “B” Signal Circuit

Sensor B is a manufacturer-defined input. Depending on the vehicle, it may represent:

P0319 does not automatically identify the right-side wheel-speed sensor. It also does not prove that the engine has an actual combustion misfire.

The code means the PCM considers the Sensor B signal missing, implausible, intermittent or outside its expected range.

P0319 belongs to the powertrain-code family covered in the complete Pro Street P-code OBD-II guide.

P0319 Quick Answer

ItemInformation
Trouble codeP0319
DefinitionRough Road Sensor “B” Signal Circuit
SystemRough-road detection and misfire validation
SeverityModerate
Safe to drive?Usually briefly, unless braking, stability-control or severe engine problems are present
Common causesSensor B fault, circuit damage, ABS data loss, communication or configuration problem
First diagnostic stepIdentify Sensor B using factory service information
Related codesP0317, P0318, ABS wheel-speed codes and communication U-codes
Typical repair rangeApproximately $100 to $1,500+, depending on the cause

What Does P0319 Mean?

The PCM detects many combustion misfires by monitoring small changes in crankshaft speed.

A healthy cylinder accelerates the crankshaft during its power stroke. A weak or missing combustion event causes a measurable decrease in crankshaft acceleration.

Driving over potholes, gravel, railroad crossings or another uneven surface can also disturb crankshaft speed through the wheels, transmission and drivetrain.

Rough-road information helps the PCM determine whether a crankshaft-speed change came from:

When the PCM detects a fault involving its designated Sensor B input, it may store P0319.

Possible fault conditions include:

The exact code-setting criteria vary by manufacturer.

What Is Rough Road Sensor B?

“Sensor B” is a diagnostic designation rather than a universal component location.

It does not necessarily mean:

Depending on the application, Sensor B may be:

A Second Physical Accelerometer

Some systems use more than one chassis or suspension acceleration sensor. Sensor B may monitor movement at a different vehicle location.

A Second Axis of One Sensor

A multi-axis sensor may measure movement in several directions. The PCM or chassis module may designate one calculated channel as Sensor A and another as Sensor B.

An ABS-Calculated Value

The ABS module may combine several wheel-speed signals and transmit more than one rough-road status or calculation.

A Network Message

Sensor B may exist only as data sent from:

This is why P0319 diagnosis must begin with manufacturer-specific service information.

Looking for a physical component labeled “B” is not a diagnostic strategy. It is how perfectly innocent sensors end up being unplugged for questioning.

Why Does the PCM Need Sensor B?

The PCM must avoid confusing road-induced drivetrain movement with engine misfires.

Sensor B may provide:

The PCM or chassis module may compare Sensor A and Sensor B to determine whether:

A Sensor B fault can reduce the system’s ability to validate crankshaft variation and misfire data accurately.

P0319 Versus P0318

P0318 and P0319 describe separate rough-road signal assignments.

CodeMeaning
P0318Rough Road Sensor A Signal Circuit
P0319Rough Road Sensor B Signal Circuit

The diagnostic distinction is important.

If only P0319 is stored:

If P0318 and P0319 appear together:

Two codes appearing together should shift attention from isolated Sensor B replacement toward shared circuits and modules.

P0319 Versus P0317

P0317 indicates that the expected rough-road hardware or information is unavailable.

P0319 identifies a more specific problem with Sensor B’s signal.

CodeDiagnostic focus
P0317Rough-road hardware, configuration or data source unavailable
P0319Sensor B signal invalid, missing or implausible

If both codes are stored, inspect:

Do not assume Sensor B is defective until the PCM has been confirmed to expect that signal on the vehicle.

P0319 Versus an ABS Wheel-Speed Code

P0319 does not necessarily identify a failed wheel-speed sensor.

Code groupGeneral intent
P0319Rough Road Sensor B signal used by the PCM
C0035–C0051Individual wheel-speed sensor or circuit fault
U-codesLost or invalid module communication

A wheel-speed sensor may contribute to Sensor B data, but the connection must be confirmed through:

For individual chassis and wheel-speed faults, visit the complete C-code OBD-II library.

Common Conditions Associated With P0319

A vehicle with P0319 may experience:

P0319 itself usually does not cause a rough idle or loss of engine power.

If the engine runs poorly, diagnose the combustion problem separately.

How Serious Is P0319?

P0319 is generally moderate in severity.

The engine may continue running normally because the fault usually affects rough-road and misfire validation rather than direct fuel or ignition control.

However, P0319 should be diagnosed because the underlying problem may involve:

Stop Driving or Seek Immediate Service If:

P0319 alone does not prove that ABS or stability control is disabled. Check those modules for their own stored codes and status.

Most Common Causes of P0319

Possible causeRelative likelihood
Damaged Sensor B wiring or connectorHigh
Faulty dedicated Sensor BHigh where equipped
Missing ABS-derived Sensor B dataHigh on calculated systems
Sensor B mounted incorrectlyMedium after repair
Sensor A/B calibration incompleteApplication dependent
Shared power or ground faultHigh when P0318 is also stored
CAN communication problemMedium
Incorrect PCM or chassis-module configurationMedium after module replacement
Damaged wheel-speed tone ring or encoderMedium on ABS-derived systems
Low battery voltage or poor groundMedium
ABS or chassis-control module faultLower
PCM failureRare

The correct diagnostic path depends on the vehicle’s definition of Sensor B.

How to Diagnose P0319

Step 1: Scan Every Control Module

Use a professional scan tool capable of accessing:

Record:

Do not clear the codes yet.

A basic engine-code reader may retrieve P0319 but miss the chassis code that identifies the failed signal source.

Step 2: Determine Whether P0319 Is Isolated

Check whether the vehicle also stores:

The code pattern provides important direction.

Code patternLikely diagnostic direction
P0319 onlyConcentrate on Sensor B and its dedicated signal path
P0318 plus P0319Inspect shared power, ground, module and communication
P0317 plus P0319Verify that Sensor B hardware is installed and configured
P0319 plus wheel-speed codeDiagnose the corresponding ABS signal first
P0319 plus lost-module codeTest communication, power and grounds
P0319 after module replacementVerify programming and configuration
P0319 plus low-voltage codesTest battery, alternator, power and grounds

Step 3: Review Freeze-Frame Data

Record the conditions under which P0319 was stored:

Determine whether the code occurred:

Step 4: Identify Sensor B

Use the correct service information to determine:

Possible signal types include:

Do not assume that P0319 uses the same diagnostic procedure on every vehicle.

Comparing Sensor A and Sensor B

Step 5: Monitor Both Sensors Simultaneously

If scan data is available, graph Sensor A and Sensor B together.

Compare their behavior while the vehicle is:

Depending on design, healthy signals may:

Use manufacturer specifications to judge correlation.

Watch for Sensor B:

Step 6: Determine Whether the Fault Is Shared or Isolated

An isolated Sensor B fault is more likely when:

A shared-system fault is more likely when:

This distinction prevents the replacement of Sensor B when the actual problem is a shared five-volt supply or module ground.

Diagnosing a Physical Sensor B

Step 7: Inspect Sensor B Mounting

If Sensor B is a dedicated accelerometer or chassis sensor, inspect:

Acceleration sensors depend on rigid, correctly oriented mounting.

A sensor attached loosely or installed backward may be electrically functional while reporting physically incorrect movement.

Step 8: Check Sensor B Power and Ground

Using the wiring diagram, verify:

Use voltage-drop testing for grounds whenever possible.

If Sensor A and Sensor B share power or ground, compare both circuits at the same time.

Normal Sensor A power with abnormal Sensor B power points toward an isolated branch-circuit fault.

Step 9: Test the Sensor B Signal

Follow the manufacturer’s test procedure for the sensor type.

Testing may include:

Watch for:

Do not strike, shake or rotate the sensor unless the service procedure specifically permits it.

Diagnosing ABS-Derived Sensor B Data

Step 10: Verify ABS Module Communication

Attempt direct scan-tool communication with the ABS or Electronic Brake Control Module.

If communication fails, inspect:

Do not replace the ABS module before confirming power, ground and network integrity.

Step 11: Compare Individual Wheel Speeds

Monitor all wheel-speed values while driving slowly and safely.

Look for:

If Sensor B is calculated from a particular group of wheel-speed inputs, a failure in one of those signals may trigger P0319.

Step 12: Inspect the Suspect Wheel-Speed Circuit

Inspect:

Use the correct procedure for active or passive sensor designs.

Step 13: Inspect the Tone Ring or Magnetic Encoder

Check for:

A wheel bearing can rotate perfectly while supplying a completely useless wheel-speed signal. Mechanical happiness and electronic happiness are not always on speaking terms.

Diagnosing Wiring, Communication and Configuration

Step 14: Inspect the Sensor B Circuit

Check for:

Move the harness while monitoring Sensor B data or waveform output.

An intermittent fault that appears during bumps may be caused by wiring movement rather than the road sensor itself.

Step 15: Inspect Shared Circuits

If P0318 and P0319 appear together, identify shared:

A shared circuit fault should be repaired before either sensor is condemned.

Step 16: Test Network Communication

If Sensor B information is transmitted through CAN, inspect:

An oscilloscope may be required to identify intermittent communication distortion.

Never apply battery voltage or an incandescent test light to a CAN signal circuit.

Step 17: Verify Module Programming

After PCM, ABS, suspension or chassis-module replacement, confirm:

A used control module may contain configuration data from another vehicle.

It may communicate normally while waiting for a Sensor B that your vehicle has never owned.

Step 18: Complete Required Calibration

Depending on the system, repairs may require:

Follow the manufacturer’s procedure exactly.

Calibration should occur only after electrical, sensor and communication faults have been repaired.

Step 19: Verify Crankshaft Monitoring

Because Sensor B supports misfire validation, inspect the crankshaft system if related codes are present.

Check:

Related resources include:

Do not replace the crankshaft sensor solely because P0319 is stored.

Step 20: Determine Whether an Actual Misfire Exists

If P0319 appears with P0300 or a cylinder-specific code, review:

A genuine misfire that occurs consistently on smooth roads requires normal combustion diagnosis.

Misfire counts appearing only during rough-road events may indicate invalid Sensor B information.

Step 21: Clear P0319 and Verify the Repair

After correcting the confirmed fault:

  1. Clear PCM and chassis-module codes.
  2. Complete required programming or calibration.
  3. Verify communication with all modules.
  4. Graph Sensor A and Sensor B data.
  5. Confirm valid wheel-speed signals.
  6. Drive on a smooth road.
  7. Cross a controlled uneven surface when safe.
  8. Monitor misfire counters.
  9. Complete the required drive cycle.
  10. Rescan every module.

The repair is confirmed when Sensor B responds correctly and P0319 does not return.

Common P0319 Repairs and Costs

RepairApproximate installed cost
Repair Sensor B connector or wiring$100–$600
Replace dedicated Sensor B$200–$900
Replace wheel-speed sensor$150–$500
Replace wheel bearing or encoder hub$300–$900
Complete Sensor A/B calibration$100–$500
Repair shared power or ground$150–$800
Repair CAN communication wiring$200–$1,500+
Program PCM or chassis module$150–$700
Replace ABS or chassis-control module$800–$2,500+

Actual costs depend on the vehicle, system design, component access and labor rate.

P0319 may require only a wiring repair, configuration correction or calibration rather than a replacement sensor.

Common P0319 Diagnostic Mistakes

Assuming Sensor B Is on the Right Side

Sensor B is a manufacturer-assigned signal, not a universal physical location.

Copying the P0318 Diagnostic Procedure Blindly

Sensor A and Sensor B may use different circuits, locations or data sources.

Ignoring Sensor A/B Correlation

Comparing both signals can quickly separate an isolated Sensor B fault from a shared-system failure.

Replacing Sensor B When Both Codes Are Present

P0318 and P0319 together often point toward shared power, ground, communication or module problems.

Ignoring Sensor Orientation

An incorrectly mounted accelerometer can produce plausible-looking but incorrect data.

Replacing a Wheel-Speed Sensor Without Checking ABS Data

Confirm the missing or erratic wheel-speed signal before replacing parts.

Ignoring Module Programming

Replacement controllers may require correct option configuration and Sensor B assignment.

Treating P0319 as an Engine Misfire

P0319 concerns rough-road information used during misfire validation. It does not prove combustion failure.

Clearing Only the PCM

Related codes may remain stored in ABS, stability, suspension or chassis modules.

P0319 Frequently Asked Questions

What does P0319 mean?

P0319 means the PCM detected a fault involving its designated Rough Road Sensor B signal.

What is Rough Road Sensor B?

It is a manufacturer-defined rough-road data source. It may be a dedicated sensor, second acceleration channel, ABS calculation or network message.

Is Sensor B the right-side wheel-speed sensor?

Not necessarily. Use manufacturer service information to identify Sensor B.

What is the difference between P0318 and P0319?

P0318 applies to Sensor A. P0319 applies to Sensor B.

What does it mean if P0318 and P0319 appear together?

A shared power, ground, module, network, configuration or calibration problem becomes more likely.

Can an ABS sensor cause P0319?

Yes, if the vehicle uses wheel-speed data to calculate the Sensor B rough-road signal.

Can a wheel bearing cause P0319?

Yes. A damaged or incorrectly installed encoder can disrupt wheel-speed information.

Does P0319 mean the engine is misfiring?

No. It means the Sensor B information used to validate misfire data is faulty.

Can PCM programming cause P0319?

Yes. Incorrect configuration can make the PCM expect the wrong Sensor B input.

Can suspension work cause P0319?

Yes. Suspension or collision repairs may disturb sensor mounting, orientation, wiring or calibration.

Can I drive with P0319?

Usually for a short distance if braking, ABS, stability control and engine operation remain normal. Drive cautiously and diagnose the fault promptly.

Will P0319 clear itself?

An intermittent fault may become historical if the signal returns, but the code may remain stored until cleared or enough successful drive cycles occur.

Related OBD-II Codes

Explore the Pro Street OBD-II Code Libraries

Use the Pro Street cornerstone pages to find additional diagnostic trouble codes:

P0319 means the PCM detected an invalid, missing or implausible Rough Road Sensor B signal.

Begin by identifying what Sensor B represents on the vehicle. Compare Sensor A and Sensor B data, inspect dedicated circuits and shared supplies, verify ABS-derived wheel-speed information, and check network communication.

If the code appeared after module, suspension or collision repair, verify configuration, sensor orientation and calibration before replacing components.

Sensor B is not automatically on the right, Sensor A is not automatically on the left, and neither one cares what the alphabet usually implies. Factory diagrams remain annoyingly useful.

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