B0104
Immobilizer Control Module Communication
1999-2000 BMW 323i E46 2.5L I6
High SeverityBodyGeneric (SAE)
Description
The immobilizer control module is not communicating with the ECM/PCM. Both modules must agree before engine starting is allowed.
Symptoms
- Engine will not start
- Security light on
- No communication with immobilizer module
- Multiple no-start codes
Common Causes
- Immobilizer module failure
- CAN bus wiring issue between modules
- ECM/PCM fault
- Power or ground issue to immobilizer module
Diagnostic Steps
- Check CAN bus communication
- Test immobilizer module power and ground
- Scan both immobilizer and ECM for codes
- Check wiring between modules
- Try key relearn procedure
Repair Notes
Repair CAN bus wiring or replace immobilizer control module. Modules may need to be paired.
Related Codes
Other Body Codes
- B0001Driver Frontal Stage 1 Deployment Control
- B0002Driver Frontal Stage 2 Deployment Control
- B0003Passenger Frontal Stage 1 Deployment Control
- B0004Passenger Frontal Stage 2 Deployment Control
- B0005Driver Knee Airbag Deployment Circuit
- B0006Passenger Knee Airbag Deployment Circuit
- B0010Driver Side Airbag Deployment
- B0011Driver Side Airbag Deployment Circuit Open
- B0012Driver Side Airbag Deployment Circuit Short to Ground
- B0013Driver Side Airbag Deployment Circuit Short to Battery
B0104 on Other Vehicles
Common Questions
What does code B0104 mean on a 1999-2000 BMW 323i E46?
B0104 stands for "Immobilizer Control Module Communication". The immobilizer control module is not communicating with the ECM/PCM. Both modules must agree before engine starting is allowed.
What are the symptoms of B0104 on a BMW 323i E46?
Common symptoms of B0104 include: Engine will not start, Security light on, No communication with immobilizer module, Multiple no-start codes.
What causes B0104 on a 1999-2000 BMW 323i E46?
Common causes of B0104 include: Immobilizer module failure, CAN bus wiring issue between modules, ECM/PCM fault, Power or ground issue to immobilizer module.