U02A3
Lost Communication With Particulate Matter Sensor
The vehicle bus reports loss of communication with the particulate matter (PM) sensor (smart sensor with own ECU). DPF post-cat soot monitoring loses its primary feedback signal.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Symptoms
- Multiple warning lights may illuminate
- Affected modules may go into limp mode or shut down
- Specific functions inoperative depending on module
- Diagnostic tools may show communication faults
Common causes
Ordered by how often each turns out to be the cause.
- Bus wiring open or shortedCommon
- Module without power or groundPossible
- Module failedPossible
Parts involved
- Pm Sensor
- Vehicle Bus Wiring
U02A3 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.