Can a dead battery cause body electrical codes?

Yes, low battery voltage is a very common cause of body electrical codes. When voltage drops, body control modules can store false codes. Always check battery health first before replacing components.

How much does a body control module replacement cost?

BCM replacement typically costs $300-$800 including programming. However, many body electrical codes are caused by simple wiring or fuse issues that cost much less to repair.

B0078

Horn Circuit Short to Ground

Moderateelectrical

Overview

The B0078 code indicates that the body control module has detected a horn circuit short to ground 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

HVAC blower not blowing air
Audio system not powering on
Power window inoperative on one or more doors
SRS indicator light stays on or flashes

Common Causes

Failed window/lock/seat motor
Faulty SRS/airbag control module
Failed HVAC actuator motor
Faulty body control module (BCM)

Diagnosis Steps

1Connect an OBD-II scanner and read all stored body control module trouble codes
2Inspect the affected circuit fuse and relay; replace if blown or faulty
3Check the wiring harness and connectors for damage, corrosion, or loose pins
4Test circuit voltage and ground with a multimeter at the affected component
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

Chevrolet SilveradoNissan AltimaToyota CamryMercedes-Benz C-Class

Related Codes

B0047 B0054 B0128

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.