A Kia involved in a collision should have had its steering wheel airbag deploy, but it didn't. A deeper look by investigators determined the airbag hadn't been connected by a collision repair facility. What's even more concerning? An airbag light wasn't illuminated after the repair, even though the airbag wasn’t connected! In most cases where the wiring harness hasn’t been modified these types of scenarios are rare. Every time the vehicles ignition is cycled, the restraint module does a self-check to verify status of airbags and other restraints. The MIL light will come on briefly then turn off is systems are operating as designed. However, the restraints work off electrical resistance that can be manipulated by cutting into the harness and adding or subtracting resistance.
Car manufacturers are facing lawsuits for airbag-related failures, mostly as a result of Takata airbag recalls. But defective airbags are not the only issue you'll come across. It's possible for even a perfect airbag not to deploy when it should, simply because of an incomplete repair or not following an OEM procedure in detail.
A disconnected airbag doesn't always set an MIL
Frequently airbag assemblies are either replaced or removed and re-installed during collision repair procedures. Dash-mounted, steering wheel, side curtain, thorax cushion - you name it, airbags are changed, OCS sensors replaced, or wiring repaired in a vast number of collision repairs.
And this is the common timeline for how it goes for many collision repair shops:
- A vehicle arrives for the repair and it's checked for illuminated MILs.
- If an airbag light is noticed, it should be scanned for DTCs.
- Often times the repairs are completed, the vehicle is checked for MILs, and if no MIL is illuminated, the vehicle is returned to the customer. DTCs may be present in the vehicle and turn on an MIL after the customer takes delivery.
- Key cycles and miles driven are often times the determining factor as to when and if the MIL illuminates.
Certain vehicles will turn on an MIL but not store DTCs which can confuse the technician running the scan tool if they aren’t properly trained. Some vehicles require the technician to check live data as part of the health check to verify activation statuses of restraint systems.
Can you imagine knowing a customer is about to drive out of your lot knowing their airbag doesn't function? Of course, you wouldn't allow that to happen. How can you be sure it doesn’t happen? You can avoid repeating the Kia scenario by scanning - in fact, it's what OEMs want you to do.
A post-repair scan is crucial
A MIL isn't on, but a DTC could be set in the module. It could be a communication DTC or something else, but in many cases, it won't illuminate a MIL.
DTCs without a corresponding MIL is why a post-repair scan is so important. Simply performing a full diagnostic scan on a vehicle after collision repairs are finished can catch situations like this.
In the Kia scenario above, the un-deployed airbag should have been detected before it left the collision repair shop. Simply scanning the vehicle with an asTech® device would have detected the disconnected airbag. By failing to scan the vehicle after repairs were made, the driver was unnecessarily put at risk of serious, potentially fatal, harm, and the repair facility was at risk of a debilitating lawsuit.
What's more, many OEMs require in their position statements that a post-repair scan should be completed. In the eyes of the manufacturer, it's mandatory to check for active or stored DTCs before AND after every collision repair. It's not just hollow advice – OEMs want to help you repair your customers' vehicles fully and safely every time. In ALL cases the vehicle service manual should be referenced by vehicle year and platform as this technology changes frequently.
The asTech® difference
A post-repair diagnostic scan provides the DTCs that are stored or active, even in the absence of an MIL, but it's still up to the technician to determine why the DTC is still present after a repair.
With asTech®, your technician isn't left wondering what went wrong. At their disposal are a few ways to tackle the DTC head-on. A remote post-repair diagnostic scan with asTech® spells out potential issues and tips to check first. Or, your technician can reach out to the asTech® Master Technicians for help with diagnosis or repair. In addition, In-shop asTech® Mobile Repair Service is available, providing hands-on expertise to correct issues that are beyond remote diagnostics or your technicians skill set.