B0102high severityBody
Immobilizer Transponder Authentication Failure
on 2002 Ford Explorer 4.0L V6 SOHC · 4WD
What this code means
The immobilizer detected a transponder signal but authentication failed. The key code does not match the stored code.
Symptoms
- Engine cranks but will not start
- Security light solid on
- Key rejected by system
Common causes
- Key not programmed to this vehicle
- Immobilizer module lost key memory
- Aftermarket key with incorrect code
- Immobilizer control module failure
Diagnostic steps
- Try all registered keys
- Check key programming status
- Attempt key relearn procedure
- Scan immobilizer module codes
- Verify VIN match in immobilizer
Repair notes
Reprogram key to vehicle using manufacturer procedure. May require dealer tool.
Other Body codes on this vehicle
B0001
Driver Frontal Stage 1 Deployment Control
B0001
Driver Frontal Stage 1 Deployment Control
B0002
Driver Frontal Stage 2 Deployment Control
B0002
Driver Frontal Stage 2 Deployment Control
B0003
Passenger Frontal Stage 1 Deployment Control
B0003
Passenger Frontal Stage 1 Deployment Control
B0004
Passenger Frontal Stage 2 Deployment Control
B0004
Passenger Frontal Stage 2 Deployment Control
B0005
Driver Knee Airbag Deployment Circuit
B0005
Driver Knee Airbag Deployment Circuit