Front Washer Relay Circuit
Table of contents
B3873 GMC Possible Causes
- Faulty Front Washer Relay
- Front Washer Relay harness is open or shorted
- Front Washer Relay circuit poor electrical connection
- Faulty Body Control Module (BCM)
How do I fix code B3873 GMC?
Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector’s pins.
Tech Notes
- B3873 01 Front Washer Relay Circuit Short to Battery
- B3873 02 Front Washer Relay Circuit Short to Ground
- B3873 04 Front Washer Relay Circuit Open
Cost of diagnosing the B3873 GMC code
The cost of diagnosing the B3873 GMC code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle’s make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.
Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
B3873 GMC Description
The windshield washer function is controlled by the Body Control Module (BCM). When the washer switch is pressed, low reference is applied through the switch contacts and the signal circuit to the body control module indicating the wash request. The body control module then applies voltage through the control circuit to the coil side of the windshield washer pump relay energizing the relay. With the relay energized, battery voltage from the fuse is applied through the switch contacts of the relay and the control circuit to the windshield washer fluid pump.