Immobilizer Control Module Communication
1990-1997 Ford Aerostar 4.0L V6
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
Ford Aerostar
1990-1997 3.0L V6
Ford Bronco
1990-1996 4.9L I6 300
Ford Bronco
1990-1996 5.0L V8 302 Windsor
Ford Bronco
1990-1996 5.8L V8 351 Windsor
Ford Bronco
2021-2024 2.3L I4 EcoBoost
Ford Bronco
2021-2024 2.7L V6 EcoBoost
Ford Bronco Raptor
2022-2024 3.0L V6 EcoBoost
Ford Bronco Sport
2021-2024 1.5L I3 EcoBoost
Common Questions
What does code B0104 mean on a 1990-1997 Ford Aerostar?
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 Ford Aerostar?
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 1990-1997 Ford Aerostar?
Common causes of B0104 include: Immobilizer module failure, CAN bus wiring issue between modules, ECM/PCM fault, Power or ground issue to immobilizer module.