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DTC codes / P2Cxx · Hybrid propulsion / P2CE8

P2CE8Particulate Filter Pressure Sensor C Circuit High

P2CE8 indicates that the powertrain control module has detected an abnormally high voltage on the signal circuit of particulate filter pressure sensor C, which is used to monitor the pressure drop across the diesel particulate filter. The sensor's output is above the expected range for the current operating conditions, so the module flags the circuit as high.

SystemPowertrain
Code typeGeneric (all makes)
SeverityMedium
Fix difficultyIntermediate
AreaHybrid propulsion

Symptoms you may notice

  • Illumination of the check engine light, often with no other noticeable symptoms
  • Reduced engine power or limp mode in some vehicles as a protective measure
  • A message on the dash indicating a particulate filter or emissions system fault
  • Possible poor fuel economy or increased regeneration frequency
  • In rare cases, a noticeable hesitation or rough running if the fault affects load calculations

Common causes, most likely first

  1. Faulty particulate filter pressure sensor C
  2. Damaged or chafed wiring in the sensor signal circuit, causing a short to voltage
  3. Corroded or loose electrical connector at the sensor or PCM
  4. Failed PCM driver or internal circuit for the sensor signal
  5. Excessive soot or ash buildup in the particulate filter creating abnormal pressure readings
  6. Water or contamination intrusion into the sensor or connector
  7. Aftermarket or incorrect sensor installed previously

How to diagnose and fix it

  1. Perform a visual inspection of the sensor, connector, and wiring for damage, corrosion, or contamination
  2. Check for technical service bulletins or known issues for the specific vehicle make and model
  3. Use a scan tool to read live data from the particulate filter pressure sensors and compare values with key-on, engine-off and idle conditions
  4. Measure the sensor signal voltage with a multimeter and compare to the manufacturer's specification
  5. Disconnect the sensor and inspect the connector pins for tightness and corrosion; clean or repair as needed
  6. Check the sensor reference voltage and ground circuits for proper operation
  7. If the sensor and wiring test good, follow the manufacturer's diagnostic flow to rule out the PCM or filter restriction

What the pressure sensor signal really tells you

  • A high signal voltage does not always mean the sensor has failed; a short to voltage in the harness or a poor ground can produce the same reading.
  • Excessive backpressure from a loaded or damaged particulate filter can push the sensor signal high, so always check filter restriction before replacing the sensor.
  • Some vehicles use multiple pressure sensors (A, B, C) and a high code on one may be caused by a shared reference or ground circuit affecting all sensors.
  • After repairs, the code may not clear immediately because the PCM requires a complete drive cycle with specific conditions to re-evaluate the circuit.
  • A contaminated or wet connector is a common cause that is often overlooked during diagnosis, especially after engine washing or off-road use.

Can I keep driving with P2CE8?

You can generally continue driving with this code, but avoid heavy loads and long periods of high-speed driving until it is diagnosed, as the fault may affect particulate filter regeneration and emissions compliance. If the engine enters limp mode or you notice reduced power, have the vehicle checked promptly.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

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