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Home/DTC Codes/Pontiac/Sunfire/1995-2005 2.2L I4/B0421
B0421

ABS Warning Lamp Circuit

1995-2005 Pontiac Sunfire 2.2L I4

Moderate SeverityBodyGeneric (SAE)

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

  1. Check lamp during key-on bulb check
  2. Scan ABS module for codes
  3. Test lamp drive circuit
  4. Inspect wiring from ABS module to cluster

Repair Notes

Replace ABS warning lamp or repair wiring circuit.

Related Codes

B0400Instrument Cluster General MalfunctionB0420Check Engine Lamp Circuit

Other Body Codes

B0421 on Other Vehicles

Pontiac Aztek

2001-2005 3.4L V6

Pontiac Bonneville

1990-1999 3.8L V6

Pontiac Bonneville

2000-2005 3.8L V6

Pontiac Bonneville GXP

2000-2005 4.6L V8

Pontiac Bonneville GXP

2000-2005 4.6L V8 Northstar

Pontiac Bonneville SSEi

1992-1999 3.8L Supercharged V6

Pontiac Bonneville SSEi

1992-1999 3.8L V6 Supercharged

Pontiac Firebird

1993-1997 3.4L V6

Common Questions

What does code B0421 mean on a 1995-2005 Pontiac Sunfire?

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 Pontiac Sunfire?

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 1995-2005 Pontiac Sunfire?

Common causes of B0421 include: Burnt out lamp, Cluster fault, ABS module lamp driver failure, Wiring issue.

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