BMW DTC P0691 – Fan 1 Control Circuit Low
DTC P0691 meaning on BMW
The Diagnostic Trouble Code (DTC) P0691 for BMW indicates a fault in the Fan 1 Control Circuit, specifically signaling a low voltage condition. This fault code is typically related to issues with the cooling fan control system in the vehicle.
BMW DTC P0691 symptoms
Symptoms associated with BMW DTC P0691 may include:
- Engine overheating
- Malfunctioning cooling fan
- Check Engine Light (CEL) illuminated on the dashboard
BMW DTC P0691 causes
Common causes of BMW DTC P0691 include:
- Defective cooling fan relay
- Wiring issues in the fan control circuit
- Faulty engine coolant temperature sensor
BMW DTC P0691 seriousness
The seriousness of BMW DTC P0691 lies in the potential for engine overheating, which can lead to severe damage if not addressed promptly. It is crucial to diagnose and resolve this issue to prevent engine damage and ensure proper cooling system functionality.
How to diagnose DTC P0691 on BMW
To diagnose BMW DTC P0691, you can follow these steps:
- Use a diagnostic scanner to retrieve the fault code
- Inspect the cooling fan relay for proper operation
- Check the wiring and connectors in the fan control circuit for any damage or loose connections
- Test the engine coolant temperature sensor for functionality
How to fix DTC P0691 on BMW
To fix BMW DTC P0691, you can consider the following actions:
- Replace the faulty cooling fan relay
- Repair or replace any damaged wiring or connectors in the fan control circuit
- Replace the engine coolant temperature sensor if found to be defective
How to erase DTC P0691 on BMW
To erase DTC P0691 on BMW, you can clear the fault code using a diagnostic scanner. After addressing the underlying issue causing the fault code, you can reset the code to turn off the Check Engine Light and ensure that the repair was successful.
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
Some of the links on this page may be affiliate links, which means we may earn a small commission if you make a purchase. This helps us keep our DTC database up to date and provide valuable content for free. We only recommend products that we have tested and believe to be the best in their class.