Fault code P0328 – a step-by-step guide to diagnosing and fixing it

Error code P0328 is displayed and the check engine light is on - what does this mean?

DTC P0328 is detected by the OBD system when knock sensor 1 sends a voltage signal to the engine control unit that is too high. This EOBD code relates to the knock detection system, which protects the engine from harmful combustion noises. Different manufacturers may have slightly different names for this trouble code, but it always refers to the knock sensor circuit.

What causes can this fault code have?

• Defective knock sensor 1
• Damaged cable to the knock sensor
• Loose plug connections on the knock sensor
• Corroded contacts in the sensor plug
• Faulty ground connection of the sensor
• Defective engine control unit
• Mechanical vibrations due to defective engine mounts
• Incorrect sensor installation or loose fastening

Which symptoms occur in parallel with error code P0328?

• Engine problems: Unsteady idling and reduced engine power due to faulty knock control. Knocking noises: Metallic ringing or knocking when accelerating because the ignition timing is not adjusted correctly. Fuel consumption: Increased consumption due to suboptimal combustion. Exhaust gas problems: Deteriorated exhaust gas values and possible damage to the catalytic converter. Check engine light: Permanent illumination of the warning light in the dashboard.

How can the problem of error code P0328 be rectified?

• The repair requires a systematic diagnosis of the knock detection system.
• Replace the knock sensor: Remove the defective sensor 1 and replace it with a new original part, observing the correct tightening torque
• Repair wiring harness: Locate damaged wires to the knock sensor, repair severed wires or replace the entire wiring harness
• Clean plug connections: Disconnect sensor plug, clean contacts with contact spray and check for tight fit
• Check the ground connection: Clean the knock sensor's earth point, remove corrosion and tighten the connection firmly
• Check engine mounts: Identify and replace defective bearings to eliminate mechanical vibrations
• Replace engine control unit: If ECU malfunction is proven, replace the control unit with a new or reconditioned unit