B1477: Wiper Motor Circuit Short to Ground
The B1477 code indicates that the body control module (BCM/GEM) or the wiper system control module has detected a short to ground in the front wiper motor circuit, specifically in the high and low speed control lines. This prevents proper switching between speeds or may cause complete loss of wiper function, as the module registers abnormally low resistance in the control path to the motor.
1. Commonly Affected Makes
2. Most Common Causes
- Front wiper motor with internal winding shorted to ground
- Wiring between control module and wiper motor shorted to chassis or ground
- Damaged wiper motor connector with bent pins or water/corrosion causing ground contact
- Faulty wiper control relay with internal short or coil shorted to ground (depending on vehicle circuit design)
- Internal failure in the body control module (BCM/GEM) keeping the motor circuit grounded
3. Symptoms You Will Notice
- Wipers operate only at one speed or fail to switch between high and low
- Wipers do not work at all
4. Step-by-Step Diagnosis
Check for technical service bulletins (TSBs) related to wiper system for the specific vehicle
Inspect wiper motor connector for damage, corrosion, or bent pins; repair or replace as needed
Test wiper motor by applying power and ground directly to verify operation
Check for short to ground in wiring between BCM and wiper motor using a multimeter
Test wiper control relay for internal short to ground
If all else is normal, suspect a faulty BCM and perform further module diagnostics
5. Frequently Asked Questions
Is it safe to drive?▼
Yes, it is generally safe to drive, but you will not have functioning windshield wipers, which can be dangerous in rain or snow. Have the issue repaired promptly.
How much does it cost to fix?▼
Repair costs typically range from $100 to $400, depending on the cause. A wiper motor replacement may cost $150-$300, while BCM replacement can be $300-$800 including programming.