◆OBD Codes

B0042

SRS Warning Lamp Circuit Open

Severeelectrical

Overview

The B0042 code indicates that the body control module has detected a srs warning lamp circuit open condition. This relates to the vehicle's body electrical systems, which control comfort, convenience, and safety features. When this code is stored, the affected system or component may not operate correctly, potentially impacting safety or comfort features.

Symptoms

  • Airbag warning light illuminated on dashboard
  • Windshield wipers not operating or stuck
  • SRS indicator light stays on or flashes
  • Turn signals flashing rapidly or not at all

Common Causes

  • Damaged clock spring in steering column
  • Corroded or damaged wiring harness connectors
  • Corroded battery terminals
  • Short circuit in wiring

Diagnosis Steps

  1. 1Connect an OBD-II scanner and read all stored body control module trouble codes
  2. 2Inspect the affected circuit fuse and relay; replace if blown or faulty
  3. 3Check the wiring harness and connectors for damage, corrosion, or loose pins
  4. 4Test circuit voltage and ground with a multimeter at the affected component
  5. 5Verify battery voltage is within specification (12.4V+ engine off)

Estimated Repair Cost

$75 — $800

Cost varies by vehicle, location, and repair shop. Includes parts and labor.

Commonly Affected Vehicles

Subaru OutbackMercedes-Benz C-ClassMazda CX-5Toyota Camry

Related Codes

B0054B0023B0128

More Electrical Codes

B0001Driver Frontal Airbag Deployment Loop Circuit Open
Critical
B0002Driver Frontal Airbag Deployment Loop Circuit Short to Ground
Critical
B0003Driver Frontal Airbag Deployment Loop Circuit Short to Battery
Critical
B0004Driver Frontal Airbag Deployment Loop Resistance Too High
Critical
B0005Driver Frontal Airbag Deployment Loop Resistance Too Low
Critical
B0006Passenger Frontal Airbag Deployment Loop Circuit Open
Critical

Frequently Asked Questions

Driving with the airbag warning light on means the SRS system may not deploy in a crash, which significantly increases injury risk. Have the system inspected as soon as possible.