U0102
Lost Communication with Transfer Case Control Module
2001-2003 BMW 525iT E39 2.5L I6 🇨🇦
High SeverityNetwork
Description
Cannot communicate with the transfer case control module that manages AWD/4WD operation.
Symptoms
- 4WD/AWD warning light on
- Transfer case stuck in mode
- Cannot switch between 2WD and 4WD
- Service 4WD message
Common Causes
- Transfer case module power failure
- CAN bus wiring to module
- Transfer case module failure
- Fuse blown
- Connector corrosion
Diagnostic Steps
- Check transfer case module fuse
- Test module power and ground
- Inspect CAN bus wiring to module
- Try direct communication with module
- Check connector for corrosion
Repair Notes
Check fuses and power supply first. Common on trucks after water fording.
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
U0102 on Other Vehicles
Common Questions
What does code U0102 mean on a 2001-2003 BMW 525iT E39?
U0102 stands for "Lost Communication with Transfer Case Control Module". Cannot communicate with the transfer case control module that manages AWD/4WD operation.
What are the symptoms of U0102 on a BMW 525iT E39?
Common symptoms of U0102 include: 4WD/AWD warning light on, Transfer case stuck in mode, Cannot switch between 2WD and 4WD, Service 4WD message.
What causes U0102 on a 2001-2003 BMW 525iT E39?
Common causes of U0102 include: Transfer case module power failure, CAN bus wiring to module, Transfer case module failure, Fuse blown, Connector corrosion.