What it means
A sensor regeneration cycle (heating to burn off accumulated soot) did not complete - sensor cannot return to measurement mode.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The PM sensor periodically heats its sensing element to burn off accumulated soot before returning to measurement mode. This code sets when a regeneration cycle does not finish, leaving the sensor unable to resume normal measurement.
Common causes
Most likely first.
- Regeneration cycle interrupted before completion
- Conditions required for regeneration not met
- Fault in the sensor heater or temperature circuit
- Power or communication interruption during regeneration
Symptoms
- Check-engine light on
- Particulate matter sensor or aftertreatment warning
- Emissions inspection failure
How to diagnose it
- Check freeze-frame data and scan-tool history for when regeneration stopped and whether the required operating conditions were present.
- Review live PM-sensor status and temperature data to determine whether the sensor returned to measurement mode.
- Inspect the PM sensor wiring and connector for damage, loose pins, or signs of heat or moisture.
- Check the sensor heater and temperature circuit for opens, shorts, or poor connections.
- If the circuits pass, follow the manufacturer's procedure to complete regeneration and confirm that the sensor returns to measurement mode.
Common fixes
- Allow the vehicle to meet the manufacturer's conditions for a complete sensor regeneration.
- Repair a loose or damaged PM-sensor connector or wiring.
- Repair a fault in the heater or temperature circuit.
- Replace the PM sensor if its heater or temperature sensing function fails testing.
Can I keep driving?
The vehicle is generally driveable, but the PM sensor may not report soot correctly and emissions compliance can be affected. Follow any aftertreatment warning instructions and avoid repeatedly interrupting a required regeneration.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.