What it means
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.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Knock sensor D picks up combustion vibration and sends a signal to the engine control module, which uses it to manage ignition timing. This code means the signal is above the module's upper limit, often because the signal wire is open or shorted to a power supply.
Common causes
Most likely first.
- Open signal line
- Gateway module routing CAN messages incorrectly
- CAN terminating resistor (120 Ω) drifted out of spec
Symptoms
- Check-engine light
- Reduced engine power or acceleration
- Engine knocking may be more noticeable
How to diagnose it
- Record freeze-frame data and monitor sensor D's live reading to confirm the high signal and see whether it remains high or changes with engine operation.
- Use service information to locate sensor D, then inspect its connector and wiring for chafing, water ingress, loose pins, or damage near the engine.
- Check the sensor D signal circuit for an open, a short to supply voltage, or poor pin contact, following the manufacturer's test procedure.
- Test knock sensor D itself and verify its mounting if the circuit wiring and connections meet specification.
- If the sensor and circuit pass, check related communication faults and the gateway or CAN network for a confirmed fault.
Common fixes
- Reconnect or repair a damaged sensor D connector.
- Repair the open or shorted sensor D signal wire.
- Correct a loose or damaged connector pin.
- Replace knock sensor D if it fails the manufacturer's tests.
- Repair a confirmed gateway or CAN network fault.
Can I keep driving?
Drive only as needed and avoid high loads until diagnosed, since the module may not be able to interpret knock sensor D's signal correctly. Stop if the engine knocks persistently or power drops sharply.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.