BMW DTC P0685 – ECM/PCM Power Relay Control Circuit/Open
DTC P0685 meaning on BMW
The Diagnostic Trouble Code (DTC) P0685 for BMW refers to the ECM/PCM Power Relay Control Circuit/Open. This code indicates that there is an open circuit or a fault in the power relay control circuit of the Engine Control Module (ECM) or Powertrain Control Module (PCM).
BMW DTC P0685 symptoms
Symptoms of DTC P0685 on a BMW may include:
- Engine stalling or not starting
- Loss of power
- Check Engine Light (CEL) illuminated on the dashboard
- Difficulty in starting the vehicle
BMW DTC P0685 causes
The common causes of DTC P0685 on a BMW include:
- Defective ECM/PCM power relay
- Open or short circuit in the power relay control circuit
- Corrosion or poor connection in the wiring related to the power relay
BMW DTC P0685 seriousness
DTC P0685 can be a serious issue as it can lead to engine performance problems and potential stalling of the vehicle. Ignoring this code may result in further damage to the vehicle’s ECM/PCM or other components.
How to diagnose DTC P0685 on BMW
To diagnose DTC P0685 on a BMW, you can follow these steps:
- Use a diagnostic scanner to retrieve the fault codes stored in the ECM/PCM.
- Inspect the power relay and its control circuit for any visible damage or corrosion.
- Check the wiring harness and connectors for any signs of wear or poor connections.
- Perform continuity and resistance tests on the power relay and circuit to identify any open circuits.
How to fix DTC P0685 on BMW
To fix DTC P0685 on a BMW, you can try the following solutions:
- Replace the faulty ECM/PCM power relay with a new one.
- Repair any open or short circuits in the power relay control circuit.
- Clean or replace any corroded connectors or wiring related to the power relay.
- Clear the fault codes using a diagnostic scanner after the repairs are completed.
How to erase DTC P0685 on BMW
To erase DTC P0685 on a BMW, you can use a diagnostic scanner to clear the fault codes stored in the ECM/PCM memory. After fixing the underlying issue causing the code, you can reset the system by erasing the code and performing a test drive to ensure the problem has been resolved.