P234A
Cylinder 9 Pressure Sensor Circuit Low
Cylinder 9 pressure sensor below lower plausibility — short to ground. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: hard
Common causes
Ordered by how often each turns out to be the cause.
- Sensor signal shorted to groundCommon
- Sensor internal shortPossible
- Connector pins corroded - high contact resistanceLess likely
Parts involved
- Cylinder Pressure Sensor 9
P234A is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.