What it means
A general electrical fault on knock sensor D — used on engines with multiple knock sensors (one per bank or per cylinder pair).
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Knock sensor D detects engine-block vibration caused by combustion and sends a signal to the engine control module, which can adjust ignition timing to limit knock. This code means the module has detected a general electrical fault in sensor D's circuit, rather than a signal specifically judged too low or too high.
Common causes
Most likely first.
- Sensor failed
- 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 check live knock-sensor readings for sensor D to see when the fault occurs and whether its signal is missing or implausible.
- Confirm the vehicle's sensor layout identifies a knock sensor D, then inspect that sensor's connector and wiring for damage, corrosion, loose pins, or poor contact.
- Check that sensor D is securely mounted at the specified location and that its wiring is routed clear of heat, vibration, and moving parts.
- Test sensor D's circuit continuity and isolation for shorts or opens, following the manufacturer's procedure and specification.
- If the sensor circuit tests correctly, check related module communication faults and gateway or network wiring before considering a module fault.
Common fixes
- Reconnect or repair a loose or corroded sensor D connector.
- Repair damaged wiring in the sensor D circuit.
- Secure or replace knock sensor D if it fails the manufacturer's tests.
- Repair a confirmed gateway or CAN network fault.
Can I keep driving?
If the engine runs normally, limit driving and avoid heavy acceleration or loads until the fault is diagnosed, since the module may not be able to respond properly to knock. Stop if you hear persistent knocking or notice a major loss of power.
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.