P139C – BMW DTC

BMW DTC P139C – Crankshaft Position Sensor Pulse-Width Error

DTC P139C meaning on BMW

DTC P139C on a BMW indicates a crankshaft position sensor pulse-width error. This fault code is triggered when the engine control module (ECM) detects that the pulse width signal from the crankshaft position sensor is outside the expected range.

BMW DTC P139C symptoms

Symptoms of a DTC P139C on a BMW may include:

• Engine misfires
• Reduced engine performance
• Difficulty starting the engine
• Engine stalling
• Illuminated check engine light

BMW DTC P139C causes

The common causes of a DTC P139C on a BMW include:

• Faulty crankshaft position sensor
• Wiring or connector issues in the crankshaft position sensor circuit
• ECM software or hardware problems

BMW DTC P139C seriousness

Ignoring a DTC P139C on a BMW can lead to potential engine performance issues, including misfires and stalling. It is important to address this fault code promptly to prevent further damage to the vehicle.

How to diagnose DTC P139C on BMW

To diagnose a DTC P139C on a BMW, a mechanic may perform the following steps:

1. Use a diagnostic scanner to retrieve the fault code and freeze frame data
2. Inspect the crankshaft position sensor and its wiring for any visible damage
3. Test the crankshaft position sensor using a multimeter to check for proper resistance and signal output
4. Check the ECM for any software updates or faults

How to fix DTC P139C on BMW

To fix a DTC P139C on a BMW, the following steps may be taken:

1. Replace the faulty crankshaft position sensor
2. Repair any damaged wiring or connectors in the sensor circuit
3. Update the ECM software if necessary

How to erase DTC P139C on BMW

After fixing the underlying issue causing the DTC P139C on a BMW, the fault code can be erased using a diagnostic scanner. This will clear the code from the ECM’s memory and turn off the check engine light.

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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