Powertrain, generic (extended)

P235D Cylinder 11 Pressure Sensor Circuit Range/Performance

Check engine lightOn

EmissionsRelevant

Drive cycleRequired

Limp modeNo

P235D is set when the combustion pressure reported for cylinder 11 is electrically valid yet does not fit the engine's state – for example a compression peak that is clearly off while no fuel is being injected. Only engines with twelve cylinders have a cylinder 11, and none of them is publicly documented with pressure sensors, so no manufacturer describes this code. CARB demands rationality checks of input components in both directions, reading too high and too low. BorgWarner's piezo-resistive pressure glow plug is calibrated and programmed specifically for each customer: a plug taken from another engine application can therefore read wrong while being electrically sound. Carbon on the heater rod or a leaking seal at the plug seat are other likely causes. The cylinder-1 counterpart is P0396; drivers seldom notice more than the lamp.

Likely causes

Deposits on the heater rod distort the reading

Glow plug with calibration for another engine application fitted

Seal at the glow plug seat leaking

Symptoms

Check engine light on
Driving behaviour practically unchanged

Repair estimate

DifficultyMediumWorkshop job

Parts and labour€80–500

Time0.5–3.5 h

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

Parts involved

cylinder pressure sensor glow plugsensor wiringengine control module

References: law.cornell.edu, borgwarner.com.