P2348 Cylinder 9 Pressure Sensor Circuit

A cylinder pressure sensor, usually built into the glow plug of a diesel, reports the combustion pressure of one cylinder so the ECM can trim injection for it. P2348 is the general circuit code for the sensor of cylinder 9, meant for modules that do not split faults into low and high. No manufacturer documents this code publicly: the systems found so far sit on four-cylinder diesels – the GM-built 2.0 CDTI of the Saab 9-5 relies on the split low/high codes, VW's US 2.0 TDI its own P13CE series – and an engine with a ninth cylinder and such sensors is not documented. The text therefore relies on CARB's circuit-monitoring duty for input sensors and on the cylinder-1 analogue P0395. Wiring, connector and sensor are the suspects; the ECM simply stops combustion control for that cylinder.

Likely causes

Symptoms

• Check engine light on
• Often no noticeable change in driving
• Possibly slightly harsher combustion noise

Repair estimate

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

Parts involved

Related codes

References: law.cornell.edu, borgwarner.com, static.nhtsa.gov.