OBD-II code · Network
U04A4 Invalid Data Received From Particulate Matter Sensor A
A receiving module detected implausible data from particulate matter sensor A (smart sensor with own ECU). PM concentration values fail plausibility checks and are rejected.
Is it safe to drive with U04A4?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyModule internal fault or sensor input drift
- PossibleSoftware version mismatch after replacement
- Less likelyGateway module routing CAN messages incorrectly
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
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 0.5–3 h
- Emissions test
- Likely to fail
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Pm Sensor A
Related codes
- U04B2Invalid Data Received From Particulate Matter Sensor B
- U04A1Invalid Data Received From Hybrid/EV Battery Interface Control Module A
- U04A2Invalid Data Received From Hybrid/EV Battery Interface Control Module B
- U04A3Invalid Data Received From Hybrid/EV Battery Interface Control Module C
- U04A5Invalid Data Received From Hybrid/EV Battery Interface Control Module E
- U04A6Invalid Data Received From Hybrid/EV Battery Interface Control Module F
- U04A7Invalid Data Received From Hybrid/EV Battery Interface Control Module G
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.