Powertrain, generic (extended)

P2368 Cylinder 12 Pressure Sensor Circuit Low

Check engine lightOn

EmissionsRelevant

Drive cycleRequired

Limp modeNo

P2368 is stored when the voltage coming from the cylinder 12 pressure sensor stays below its lower limit. As the last cylinder of a V12 or W12, it has no publicly documented application, so Saab's 9-5 diesel code P0397 serves as the template. There, the scan tool shows peak combustion pressure in a normal band of 0 to 9,000 kPa; a signal wire touching ground or a missing 5 V reference pins the value at the bottom. In Saab's test an intact signal path jumps above 10,000 kPa once the plug is disconnected – a reading that stays low with the connector off therefore points to the harness rather than the sensor. Being a Type B code there, it needs two faulty trips before the lamp lights. The opposite case is P2369.

Likely causes

Signal wire shorted to ground

5 V reference open or shorted to ground

Sensor electronics in the glow plug head failed low

Symptoms

Warning lamp after two trips with the fault
Peak pressure of cylinder 12 stuck near zero

Repair estimate

DifficultyMediumWorkshop job

Parts and labour€50–600

Time0.5–4 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: saabwisonline.com, law.cornell.edu.