P0668 – BMW DTC

BMW DTC P0668 – Control Module Internal Temperature Sensor ‘A’ Circuit Low

DTC P0668 meaning on BMW

DTC P0668 indicates that there is a fault with the Control Module Internal Temperature Sensor ‘A’ Circuit on a BMW vehicle. This sensor is responsible for monitoring the internal temperature of the control module. When the sensor detects a low circuit voltage, the DTC P0668 is triggered.

BMW DTC P0668 symptoms

Symptoms of DTC P0668 on a BMW may include:

• Check Engine Light illuminated on the dashboard
• Engine running rough or misfiring
• Reduced engine performance
• Potential stalling or difficulty starting the engine

BMW DTC P0668 causes

The common causes of DTC P0668 on a BMW include:

• Faulty Control Module Internal Temperature Sensor ‘A’
• Wiring or connection issues in the sensor circuit
• Corrosion or poor contact in the sensor connector
• Internal control module issues

BMW DTC P0668 seriousness

While DTC P0668 may not always result in immediate drivability issues, it is important to address this fault promptly. Ignoring this DTC can lead to potential engine performance issues and may cause further damage to the vehicle over time.

How to diagnose DTC P0668 on BMW

To diagnose DTC P0668 on a BMW, a mechanic would typically perform the following steps:

1. Use a diagnostic scanner to retrieve the fault code and freeze frame data
2. Inspect the wiring and connectors related to the Control Module Internal Temperature Sensor ‘A’
3. Test the sensor’s resistance and voltage readings
4. Check for any internal control module issues

How to fix DTC P0668 on BMW

To fix DTC P0668 on a BMW, the following steps may be taken:

1. Replace the faulty Control Module Internal Temperature Sensor ‘A’
2. Repair any wiring or connection issues in the sensor circuit
3. Clean or replace the sensor connector if necessary
4. If internal control module issues are detected, repair or replace the control module

How to erase DTC P0668 on BMW

After the underlying issue causing DTC P0668 on a BMW has been resolved, the fault code can be cleared using a diagnostic scanner. This will erase the code from the vehicle’s memory and turn off the Check Engine Light. It is important to ensure that the repair has been successful before clearing the DTC.

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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