B0421
ABS Warning Lamp Circuit
1999-2000 BMW 528iT E39 2.8L I6 🇩🇪
Moderate SeverityBody
Description
Malfunction in the ABS warning lamp circuit. The lamp may not illuminate or may stay on incorrectly.
Symptoms
- ABS light does not come on during bulb check
- ABS light always on
- Cannot determine ABS system status
- Light flickering
Common Causes
- Burnt out lamp
- Cluster fault
- ABS module lamp driver failure
- Wiring issue
Diagnostic Steps
- Check lamp during key-on bulb check
- Scan ABS module for codes
- Test lamp drive circuit
- Inspect wiring from ABS module to cluster
Repair Notes
Replace ABS warning lamp or repair wiring circuit.
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
B0421 on Other Vehicles
Common Questions
What does code B0421 mean on a 1999-2000 BMW 528iT E39?
B0421 stands for "ABS Warning Lamp Circuit". Malfunction in the ABS warning lamp circuit. The lamp may not illuminate or may stay on incorrectly.
What are the symptoms of B0421 on a BMW 528iT E39?
Common symptoms of B0421 include: ABS light does not come on during bulb check, ABS light always on, Cannot determine ABS system status, Light flickering.
What causes B0421 on a 1999-2000 BMW 528iT E39?
Common causes of B0421 include: Burnt out lamp, Cluster fault, ABS module lamp driver failure, Wiring issue.