What it means
Knock sensor D signal jumps or drops out intermittently — usually a corroded connector or chafed wire near the cylinder head.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Knock sensor D monitors combustion-related vibration and reports it to the engine control module for knock control. This code means its signal drops out or changes unpredictably at times, often because a connector or wire loses contact as the engine vibrates.
Common causes
Most likely first.
- Intermittent connector
- 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
- Save freeze-frame data and check live sensor D readings for dropouts, noting the engine speed and conditions when they occur.
- Locate sensor D using service information and inspect its connector for corrosion, moisture, loose fit, or damaged pins.
- Follow the sensor D harness along the cylinder head area and check for chafing, heat damage, or contact with vibrating components.
- Monitor sensor D's signal while gently moving the harness and connector to reproduce a dropout without pulling on the wiring.
- If no wiring fault is found, test sensor D and its circuit continuity under the manufacturer's procedure, then check related gateway or CAN communication faults.
Common fixes
- Clean and secure an intermittent sensor D connector.
- Repair a chafed or heat-damaged section of sensor D wiring.
- Secure the harness away from vibration or hot surfaces.
- Replace knock sensor D if it intermittently fails the manufacturer's tests.
- Repair a confirmed gateway or CAN network fault.
Can I keep driving?
Keep driving to a minimum and avoid hard acceleration because sensor D may intermittently stop providing knock information. If the engine begins knocking, running roughly, or losing power, stop and have it checked.
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.