ABS Warning Lamp Circuit
2014-2016 Tesla Model S P85D Dual Motor AWD 🇩🇪
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
- B0007Rear Left Side Airbag Deployment Circuit
- B0008Rear Right Side Airbag Deployment Circuit
- B0009Rear Center Airbag Deployment Circuit
- B0010Driver Side Airbag Deployment
B0421 on Other Vehicles
Tesla Cybertruck
2024-2024 Cyberbeast Tri Motor AWD
Tesla Cybertruck
2024-2024 Dual Motor AWD
Tesla Cybertruck
2024-2024 Single Motor RWD
Tesla Model 3
2017-2020 Long Range Dual Motor AWD
Tesla Model 3
2017-2020 Performance Dual Motor AWD
Tesla Model 3
2017-2020 Standard Range Plus Single Motor RWD
Tesla Model 3
2021-2024 Long Range Dual Motor AWD
Tesla Model 3
2021-2024 Performance Dual Motor AWD
Common Questions
What does code B0421 mean on a 2014-2016 Tesla Model S?
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 Tesla Model S?
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 2014-2016 Tesla Model S?
Common causes of B0421 include: Burnt out lamp, Cluster fault, ABS module lamp driver failure, Wiring issue.