Powertrain, generic (extended)

P2CE9 Particulate Filter Pressure Sensor C Circuit Intermittent/Erratic

Check engine lightOn

EmissionsRelevant

Drive cycleNot required

Limp modeNo

P2CE9 catches a sensor C signal that jumps rather than drifts. GM's 2025 diesel tables call this a quick change check: when two consecutive raw samples of the downstream relative pressure sensor differ by more than 20 %, the sample counts as failed, and 99 failures in 200 samples set a Type B code. The test is suspended while cranking and whenever an electrical low or high fault is already present, so it really targets short dropouts. Ford's 2024–25 petrol summary lists P2CE9 within its continuous analog circuit check for gasoline particulate filters, with about 5 s to register and no separate threshold published. Loose terminals that open under engine vibration, a harness rubbing on a bracket or moisture entering the connector are the usual finds; wiggling the harness during live data helps. Sensor D uses P2CEE.

Likely causes

Loose or corroded terminal in the sensor C connector

Harness rubbing through on a bracket or exhaust part

Water entering the connector intermittently

Intermittent internal fault of the sensor

Symptoms

Warning lamp on, sometimes after rough roads or rain
Pressure value jumps in live data
Fault may disappear and return

Repair estimate

DifficultyMediumDIY possible

Parts and labour€20–300

Time0.5–2 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, fordservicecontent.com, law.cornell.edu.