October 26

Air Bag System Repair and Diagnosis

Car Maintenance, Car Safety


Sometimes the repair is simple and the diagnosis is hard!

This week we diagnosed and repaired an airbag concern on a 2003 Mazda Tribute (which incidentally is the same as a Ford Escape). Our client’s concern was that the airbag lamp was on.

Airbag Light - get it checked

While performing our diagnosis we found the lamp would not light at all and 2 codes were stored in the airbag computer. The light issue was solved by removing the instrument panel and replacing a dead bulb; this also solved one of the trouble codes.

We now focused on the other code which indicated a problem with the passenger’s side air bag. The diagnostic procedure had us look at our scan tool data while testing the side air bag module, its wiring and connections. The maximum resistance allowed in this circuit is 3.4 ohms and our scan tool reading was 3.2 ohms: very close to the maximum. Interestingly, the driver’s side had the same reading.

Further testing of components revealed no other concerns.

What we had was either an intermittent problem with a connector or component. Airbag systems are very sensitive to poor connections and these are common causes of Air Bag lights coming on.

To ensure good connections we applied Stabilant 22, a contact enhancer which creates a “good as soldered” connection to the terminals at the side airbag connector. The results on the scan tool said it all: resistance was now 2.2 ohms, very safely below maximum spec. We applied the liquid to the driver’s side with the same result likely preventing a future airbag light concern.

While an intermittent problem with the passenger’s side airbag may still be present, we had very simply created greatly improved conditions in the affected wiring circuits and could verify our results.

About the author 

Bernie Pawlik

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