B0028: Driver Side Air Bag Deployment Control (Subfault)

What it means

This code identifies a fault associated with the driver side air bag deployment control. The restraint control module sets it when it detects a problem in that deployment control; the exact fault is specified by accompanying subfault information.

How it works

This code identifies a fault in the driver-side airbag deployment control, with the listed likely circuit involving the driver-side curtain squib. The restraint control module monitors that deployment loop and stores B0028 when it detects a fault; use the subfault details to establish whether it is open, shorted, or another condition.

Common causes

Most likely first.

1. Curtain airbag squib circuit open or shorted
2. Wiring damage in A/B/C-pillar
3. SRS control module fault

Symptoms

• Airbag warning light on

How to diagnose it

1. Retrieve the SRS subfault and freeze-frame data to confirm which driver-side deployment loop is affected and the reported electrical condition.
2. Disable the SRS according to the manufacturer’s procedure, then inspect accessible driver-side curtain wiring and connectors for damage or looseness.
3. Check the harness along the A-, B-, and C-pillar route for chafing, pinching, or damage from trim or body repairs without disturbing the curtain module.
4. Test the circuit using the manufacturer-approved SRS method; do not use a test light or ordinary meter directly on the squib circuit.
5. If the harness passes, follow the service diagnostic sequence to distinguish a faulty driver-side airbag module from a restraint control module fault.

Common fixes

• Repair damaged wiring in the driver-side pillar or curtain harness using the approved SRS procedure.
• Correct a loose or damaged connector in the driver-side deployment loop.
• Repair the open or short identified by the subfault checks.
• Replace the airbag module or restraint control module only when the specified diagnostic process confirms it is faulty.

Can I keep driving?

Driver-side airbag protection may be reduced while this SRS fault is active. Have it diagnosed promptly, and avoid removing pillar trim or handling the curtain airbag wiring.