Powertrain, generic (extended)

P2CE6 Particulate Filter Pressure Sensor C Circuit Range/Performance

Check engine lightOn

EmissionsRelevant

Drive cycleRequired

Limp modeNo

P2CE6 marks a sensor C reading that is electrically valid but physically wrong. GM's 2025 diesel tables use it for a frozen downstream relative pressure signal: during transients, with engine speed changing faster than 150 rpm/s and fuel and airflow also changing quickly, the signal must move; too little variation (25OBDG04B: 0.14 % or less in 40 of 50 samples) sets a two-trip Type B code. Ford's 2024–25 petrol filter strategy runs three checks under P2CE6: an offset test after shutdown that fails at an average of 16 to 32 hPa, a rationality test that fails when the reading stays at or above the flow-based expectation for 20 s in total, and a derivative test over 2 s when exhaust flow changes by more than 225 m³/h. Hoses, condensate and drift are more likely than wiring.

Likely causes

Sensing hose to sensor C kinked, blocked or disconnected

Condensate or frozen water in the sensing line

Sensor C drifted or sluggish

Exhaust leak near the measuring point

Symptoms

Warning lamp on
Particulate filter regenerations triggered too early or too late
Filter monitoring (missing substrate test) cannot complete

Repair estimate

DifficultyMediumDIY possible

Parts and labour€20–350

Time0.3–1.5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

dpf pressure sensor cwiring harnessecm

References: gsi.ext.gm.com, gsi.ext.gm.com, fordservicecontent.com.