Powertrain, generic (extended)

P2356 Cylinder 10 Pressure Sensor Circuit Intermittent/Erratic

Check engine lightOn

EmissionsRelevant

Drive cycleRequired

Limp modeNo

P2356 points to a cylinder 10 pressure signal that drops out or jumps for moments instead of failing permanently. No manufacturer covers cylinder 10 publicly. For four-cylinder TDI engines, a 2014 Volkswagen bulletin lays out a sensible order: first push and pull the glow plug connector – a felt click or a plug that comes off easily is already the fault – then swap the plug with a neighbouring cylinder to see whether the code moves with it, and finally move the harness while watching the maximum cylinder pressure value. On a V10 with bank-wise numbering the obvious swap partner is cylinder 9 in the same bank. According to VW, the MIL can need a second drive cycle. In Saab's GM-built diesel, the erratic codes react after only 0.2 s out of range.

Likely causes

Connector not fully seated, contact lost under vibration

Wire break inside the insulation or chafe point that opens intermittently

Glow plug sensor electronics failing intermittently

Symptoms

Warning lamp that comes and goes
Fault hard to reproduce in the workshop

Repair estimate

DifficultyMediumWorkshop job

Parts and labour€40–500

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: static.nhtsa.gov, saabwisonline.com, en.wikipedia.org.