P033D
Knock/Combustion Vibration Sensor D Circuit High
Knock sensor D signal above upper plausibility — open signal or short to B+. 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: medium
Common causes
Ordered by how often each turns out to be the cause.
- Open signal lineCommon
- Gateway module routing CAN messages incorrectlyLess likely
- CAN terminating resistor (120 Ω) drifted out of specLess likely
Parts involved
- Knock Sensor
P033D 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.