Low Beam Control Circuit
Table of contents
B258A GMC Possible Causes
- Blown Low Beam Headlamp Fuse
- Low Beam Headlamp Fuse harness is open or shorted
- Low Beam Headlamp Fuse circuit poor electrical connection
- Faulty Body Control Module (BCM)
How do I fix code B258A 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
- B258A 01 Low Beam Control Circuit Short to Battery
- B258A 02 Low Beam Control Circuit Short to Ground
- B258A 04 Low Beam Control Circuit Open
Cost of diagnosing the B258A GMC code
The cost of diagnosing the B258A 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)
B258A GMC Description
With the headlamp switch in the ON position, the headlamp switch headlamp ON signal circuit is grounded through the headlamp switch. The Body Control Module (BCM) responds by applying ground to the low beam relay control circuit which energizes the low beam relay. With the low beam relay energized, the switch contacts close allowing battery voltage to flow through the low beam fuses to the low beam control circuits illuminating the low beam headlamps.