Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
Your car's engine is making a knocking noise because it's not running smoothly, and this is causing it to lose power.
The engine control unit (ECU) detects excessive knocking in the engine and limits the engine's torque to prevent damage.
P137D is triggered when the ECU detects a high frequency of super knocking events. Super knocking is an abnormal combustion process that can cause severe engine damage. To protect the engine, the ECU reduces the engine's torque output.
• Reduced engine power
• Engine knocking noise
• Poor acceleration
• Poor quality fuel
• Faulty knock sensor
• Incorrect ignition timing
ECU: Engine Control Unit
Torque: A measure of the rotational force of the engine
• Check for stored codes and freeze frame data
• Inspect knock sensor and related wiring
• Test fuel quality and octane rating
• Replace faulty knock sensor
• Use higher octane fuel
• Adjust ignition timing
• OBD-II scanner
• Multimeter
• Fuel quality tester
$150 - $500
Moderate
• BMW 3 Series
• Audi A4
• Volkswagen Golf
• Use high-quality fuel
• Regularly maintain ignition system
• Monitor engine performance
Engine Performance
• Avoid hard acceleration until fixed
• Use recommended fuel grade
• Schedule a service appointment
Check with your vehicle manufacturer for warranty coverage on engine components.
This code has become more common with the use of turbocharged engines, which are more susceptible to knocking.
High – Continued driving can lead to severe engine damage.
Driving with this issue can lead to engine failure, which is a safety hazard.
• Engine at operating temperature
• Vehicle under load
The knock sensor is typically located on the engine block, cylinder head, or intake manifold.
Q: What is engine knocking?
A: Engine knocking is a noise that occurs when fuel burns unevenly in the engine cylinders.
Q: Can I drive with a P137D code?
A: It's not recommended, as it can cause further engine damage.
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Fitment Required · Vehicle-fitment part
Commonly relevant for misfire, ignition-efficiency, and some drivability-related repairs.
Misfire and ignition-related faults commonly involve spark plugs as part of the repair path.
Check the correct plug type, gap, and engine application for your vehicle.
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Fitment Required · Vehicle-fitment part
Relevant when the fault points toward ignition-coil performance or cylinder-specific ignition issues.
Some ignition faults involve coil performance or cylinder-specific coil problems.
Match the coil to your engine and confirm the failed component before ordering.
View options on AmazonThese parts may be related to this fault category, but a code by itself does not confirm exact fitment or guarantee that replacing a part will solve the problem.