What does it mean?
P1384 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Knock Sensor 3 Circuit Malfunction .
Symptoms
- MIL on
- Ignition timing retarded as a protection measure: noticeable drop in power and throttle response
- Slight rise in fuel consumption
- Pinging may become audible under load because knock control is degraded
- Idle quality usually stays normal, which makes the fault easy to miss
Likely causes
- Open circuit or short to ground in the knock sensor 3 signal wire
- Corroded or water contaminated connector, commonly located under the intake plenum
- Mounting bolt loose or overtightened, or dirt trapped under the sensor foot
- Cracked internal piezo element inside the sensor
- Damaged shield or a poor shield ground letting noise onto the signal
- Harness chafing against the engine block
- Faulty knock sensor input circuit in the control module
How to fix it
- Compare the knock sensor 3 value in live data with the other knock sensors
- Inspect the connector and pigtail for corrosion, coolant and oil contamination
- Measure the sensor resistance and its insulation to ground
- Check wiring continuity from the sensor to the control module and look for chafe points
- Verify the mounting bolt torque after cleaning the seating surface
- Replace the sensor if resistance is out of specification or the signal stays flat
- Re-test under load and confirm that ignition timing is no longer being pulled back