Trailer Right Turn Signal Circuit
Table of contents
B3888 GMC Possible Causes
- Faulty Trailer Right Turn Signal
- Trailer Right Turn Signal harness is open or shorted
- Trailer Right Turn Signal circuit poor electrical connection
- Faulty Trailer Lighting Control Module
How do I fix code B3888 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
- B3888 02 Trailer Right Turn Signal Circuit Short to Ground
- B3888 04 Trailer Right Turn Signal Circuit Open
Cost of diagnosing the B3888 GMC code
The cost of diagnosing the B3888 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)
B3888 GMC Description
The Trailer Lighting Control Module receives a serial data message from the Body Control Module (BCM) indicating that the vehicle left or right turn signal lamp has been activated. The Trailer Lighting Control Module responds by applying a pulsating voltage to the appropriate trailer turn signal lamp through their respective control circuit illuminating the desired trailer turn signal lamp. The Diagnostic Trouble Code (DTC) sets when the Trailer Lighting Control Module detects a short to ground or an open/high resistance in the right trailer turn signal control circuit.