U0696Lost Communication With Particulate Filter Pressure Sensor C
- Generic OBD-II code · Network
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- In GM's 2025 diesel tables 25OBDG04A and 25OBDG04B, sensor C is the downstream relative pressure sensor, which reads the gauge pressure behind the particulate filter and carries its own temperature element (lost communication there is U06B6). U0696 is set when the sensor reports message faults above a fixed count or when its newest message is too old, judged as 158 failures in 200 samples at 12.5 ms intervals. Being Type A, it turns on the lamp in the first trip. GM keeps offset errors at standstill (P2CE5) and a frozen signal (P2CE6) apart. Ford's 2024 gasoline summary lists U0696 with P2CE5 for SENT filter pressure sensors, checked continuously with 5 s to register. Without this value, back pressure and filter load are estimated. Sensor D is U0697.
- What you may notice
- Check engine light, on GM diesels in the first trip
- Particulate filter regeneration based on estimates or delayed
- Likely causes
- LikelyWiring to the downstream pressure sensor damaged by heat or chafing
- PossibleInternal sensor fault that switches off the SENT output
- PossibleConnector corroded by road splash
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €60 – €400
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.