U0066 – BMW DTC

BMW DTC U0066 – Vehicle Communication Bus E (+) Open

DTC U0066 meaning on BMW

The DTC U0066 on a BMW indicates a fault with the Vehicle Communication Bus E (+) circuit. This fault means that there is an open circuit on the positive side of the communication bus, which can lead to communication issues between various control modules in the vehicle.

BMW DTC U0066 symptoms

Symptoms of the DTC U0066 on a BMW may include:

• Malfunction indicator light (MIL) illuminated on the dashboard
• Communication errors between control modules
• Loss of certain vehicle functions

BMW DTC U0066 causes

Common causes of the DTC U0066 on a BMW include:

• Corroded or damaged wiring in the communication bus circuit
• Loose or poor connections in the communication bus circuit
• Faulty control module affecting the communication bus

BMW DTC U0066 seriousness

The DTC U0066 should be addressed promptly as it can lead to communication issues between critical control modules in the vehicle. Ignoring this fault may result in the loss of certain vehicle functions or potential safety hazards.

How to diagnose DTC U0066 on BMW

To diagnose the DTC U0066 on a BMW, follow these steps:

1. Use a diagnostic scanner to retrieve the fault codes from the vehicle’s computer
2. Inspect the wiring and connections in the Vehicle Communication Bus E (+) circuit for any damage or corrosion
3. Check for loose or poor connections in the communication bus circuit
4. Test the control modules connected to the communication bus for faults

How to fix DTC U0066 on BMW

To fix the DTC U0066 on a BMW, you can:

1. Repair or replace any damaged wiring in the communication bus circuit
2. Ensure all connections in the communication bus circuit are secure and free of corrosion
3. Replace any faulty control modules affecting the communication bus

How to erase DTC U0066 on BMW

To erase the DTC U0066 on a BMW, you can:

1. Use a diagnostic scanner to clear the fault codes from the vehicle’s computer
2. After fixing the underlying issue causing the fault code, perform a drive cycle to ensure the fault does not return

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.