P0689 – BMW DTC

BMW DTC P0689 – ECM/PCM Power Relay Sense Circuit Low

DTC P0689 meaning on BMW

DTC P0689 on a BMW indicates a fault in the ECM/PCM power relay sense circuit. This code is triggered when the powertrain control module (PCM) detects a low voltage signal from the power relay sense circuit, which is responsible for monitoring the power relay that supplies power to the ECM/PCM.

BMW DTC P0689 symptoms

Symptoms of DTC P0689 on a BMW may include:

• Check Engine Light (CEL) illuminated on the dashboard
• Engine may run rough or stall
• Reduced engine performance
• Difficulty starting the vehicle

BMW DTC P0689 causes

Common causes of DTC P0689 on a BMW include:

• Faulty ECM/PCM power relay
• Wiring issues in the power relay sense circuit
• Loose or corroded electrical connections
• Defective ECM/PCM

BMW DTC P0689 seriousness

DTC P0689 should be addressed promptly as it can lead to drivability issues and potential engine damage if left unresolved. Ignoring this fault may result in further complications and increased repair costs.

How to diagnose DTC P0689 on BMW

To diagnose DTC P0689 on a BMW, follow these steps:

1. Use a diagnostic scanner to retrieve the fault code and freeze frame data
2. Inspect the power relay and its connections for any visible damage or corrosion
3. Check the wiring in the power relay sense circuit for continuity and proper connections
4. Test the power relay and replace if necessary
5. Perform a voltage test on the power relay sense circuit to determine if the ECM/PCM is receiving the correct signal

How to fix DTC P0689 on BMW

To fix DTC P0689 on a BMW, consider the following:

1. Replace the faulty ECM/PCM power relay
2. Repair any damaged or corroded wiring in the power relay sense circuit
3. Ensure all electrical connections are secure and free of corrosion
4. If the ECM/PCM is defective, replace it with a new unit

How to erase DTC P0689 on BMW

To erase DTC P0689 on a BMW, you can use a diagnostic scanner to clear the fault code from the PCM’s memory. After addressing the underlying issue that caused the fault code, clearing the code will reset the Check Engine Light and allow you to monitor the system for any recurring issues.