U1001
CAN Communication Bus Fault - No Message
2019-2024 BMW 3 Series G20 2.0L I4 Turbo B48
Moderate SeverityNetworkGeneric (SAE)
Description
A required CAN bus message is not being received. A specific module is not broadcasting its data.
Symptoms
- Specific system not responding
- Warning light for affected system
- Feature disabled
- Other modules compensating
Common Causes
- Module not powered
- Module failure
- CAN bus wiring open for that module
- Module in sleep mode stuck
- Fuse blown for module
Diagnostic Steps
- Identify which module message is missing
- Check fuse for that module
- Test power and ground
- Check CAN wiring to specific module
- Try to wake module with scan tool
Repair Notes
Identify the non-broadcasting module and check its power supply and CAN bus connection.
Related Codes
Other Network Codes
- U0001High Speed CAN Communication Bus
- U0002High Speed CAN Communication Bus Performance
- U0003High Speed CAN Communication Bus (+) Open
- U0004High Speed CAN Communication Bus (+) Low
- U0005High Speed CAN Communication Bus (+) High
- U0006High Speed CAN Communication Bus (-) Open
- U0007High Speed CAN Communication Bus (-) Low
- U0008High Speed CAN Communication Bus (-) High
- U0009High Speed CAN Communication Bus Shorted Together
- U0010Medium Speed CAN Communication Bus
U1001 on Other Vehicles
Common Questions
What does code U1001 mean on a 2019-2024 BMW 3 Series G20?
U1001 stands for "CAN Communication Bus Fault - No Message". A required CAN bus message is not being received. A specific module is not broadcasting its data.
What are the symptoms of U1001 on a BMW 3 Series G20?
Common symptoms of U1001 include: Specific system not responding, Warning light for affected system, Feature disabled, Other modules compensating.
What causes U1001 on a 2019-2024 BMW 3 Series G20?
Common causes of U1001 include: Module not powered, Module failure, CAN bus wiring open for that module, Module in sleep mode stuck, Fuse blown for module.