What it means
The vehicle bus reports loss of communication with smart DPF differential pressure sensor C. The ECM cannot read soot loading via this channel and may switch to a model-based estimate.
At a glance
- Usually lights the warning light of the system that lost communication
- Affects emissions; the car can fail an emissions test
How it works
Particulate filter pressure sensor C measures the pressure difference across a diesel particulate filter and reports it to the engine control module over the vehicle bus. This code sets when communication with sensor C is lost, so the ECM cannot use that sensor’s pressure data to estimate soot loading and may rely on a substitute estimate.
Common causes
Most likely first.
- Bus wiring open or shorted
- Module without power or ground
- Module failed
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
How to diagnose it
- Record freeze-frame data and scan the engine and emissions modules for other DPF pressure, regeneration, or communication codes.
- Check live data for sensor C’s communication status and pressure reading, comparing it with other available DPF pressure channels where the vehicle provides them.
- Inspect sensor C’s connector and bus wiring for corrosion, loose pins, heat damage, or chafing near the exhaust.
- Check sensor C’s specified power and ground, since a failed supply can cause a communication loss.
- Test the bus circuit for an open or short following the wiring diagram and manufacturer procedures.
- If the circuit and supply are sound, confirm whether pressure sensor C’s module has failed before replacement.
Common fixes
- Reconnect or repair sensor C’s connector.
- Repair damaged bus wiring to the DPF pressure sensor C.
- Restore the sensor’s power or ground supply.
- Replace pressure sensor C if its wiring and supply are sound and communication remains absent.
Can I keep driving?
A short drive may be possible if the vehicle runs normally, but avoid ignoring DPF or emissions warnings and arrange diagnosis soon. The ECM may misjudge soot loading, which can disrupt regeneration and eventually lead to restricted performance.
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.