BMW DTC P137B – Knock Control Super Knocking Caused by Defective Knock Sensor
DTC P137B meaning on BMW
DTC P137B on a BMW refers to Knock Control Super Knocking Caused by Defective Knock Sensor. This diagnostic trouble code indicates that the engine control module (ECM) has detected abnormal combustion, known as knocking or pinging, due to a malfunctioning knock sensor.
BMW DTC P137B symptoms
Symptoms of DTC P137B on a BMW may include engine knocking noises, reduced engine performance, decreased fuel efficiency, and in some cases, the vehicle may go into a reduced power or limp mode to prevent engine damage.
BMW DTC P137B causes
The primary cause of DTC P137B on a BMW is a defective knock sensor. The knock sensor is responsible for detecting abnormal combustion in the engine and sending signals to the ECM to adjust ignition timing accordingly. A faulty knock sensor can lead to inaccurate readings and improper adjustments, resulting in engine knocking.
BMW DTC P137B seriousness
Ignoring DTC P137B on a BMW can lead to potential engine damage over time. Knocking or pinging can cause stress on internal engine components and may result in premature wear or failure if not addressed promptly. It is important to diagnose and fix this issue to prevent further damage.
How to diagnose DTC P137B on BMW
To diagnose DTC P137B on a BMW, a mechanic will typically use a diagnostic scan tool to retrieve the fault codes stored in the ECM. They will then inspect the knock sensor and its wiring for any signs of damage or corrosion. Additionally, a test drive may be conducted to listen for engine knocking and verify the symptoms.
How to fix DTC P137B on BMW
The most common fix for DTC P137B on a BMW is to replace the defective knock sensor. The faulty sensor should be removed and a new one installed following manufacturer’s specifications. It is also recommended to clear the fault codes from the ECM after the repair is completed.
How to erase DTC P137B on BMW
To erase DTC P137B on a BMW, a diagnostic scan tool capable of clearing fault codes is required. The mechanic or vehicle owner can use the scan tool to access the ECM, navigate to the fault codes section, and select the option to clear the stored DTC P137B. Once the fault code is successfully erased, the ECM will no longer register the code as active.
Recommended tools & DTC Scanners for BMW
Best Diagnostic App for modern BMWs: BimmerLink
Recommended Bluetooth adapter for Bimmerlink: OBDLink CX
Cable adapter for Bimmerlink: Enet Cable USB Type C
For older BMWs we recommend: Autel AutoLink AL319 (2024 version)
Easy-to-use Multimeter for reliable diagnostics: AstroAI Auto-ranging Multimeter
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