Question: My question for you is about my 1993 Mustang GT 鈥� or, as I refer to it, my dust collector, as this is my weekend/sunny-day-only driver. The car has only 87,000 kilometres. This spring, when I was getting the car out of winter storage, I noticed the 鈥渁irbag鈥� light blinking. I have tried going online for answers but no help, and no, the car has never been in any front or rear accidents. The battery was old, so I replaced it that thinking it might be the culprit.
Would you have any input as to what the issue might be? The dealer would like to charge me $145 an hour to check out. There is no place that I can find to plug in a code reader.
G.W.
Answer: Your Mustang predates scan tool diagnostics for the SRS (supplemental restraint system) but is friendly enough to automatically display diagnostic trouble codes via the SRS malfunction indicator lamp. Those flashes you see can be counted; each code is a two-digit number. For example a code 32 will be three flashes, a pause, then two more. There鈥檚 a three-second pause, then the code will repeat, or another code will follow.
On your Mustang, there are 17聽possible faults that can be identified and displayed via the light. Codes typically indicate a circuit or component fault. On your fairly simple two-bag system not containing passenger seat sensors, my best guess would be possibly a code 32, caused by a faulty clock spring. This is a wind-up ribbon cable at the top of the steering column that allows a continuous electrical connection to the driver鈥檚 side (steering wheel) airbag regardless of rotational position. After many steering wheel movements, it鈥檚 not uncommon for this part to fray and lose one or more electrical connections (possibly airbag, horn, or steering wheel button functions).
The retrieved code鈥檚 diagnostic chart might indicate a circuit fault related to the driver鈥檚 side airbag, or other circuits, and it would take some skilled sleuthing to determine the specific location of the fault. Due to safety concerns, needed service information/interpretation and system disassembly, this is a job best left to a pro, which could be the dealer or an independent repair facility.
Q: My check-engine light came on. A friend told me to tighten my gas cap, which I did. Nothing happened, and then over a week later, the light went out. Why would this be?
A.D.
A: It seems your vehicle may have detected an EVAP system leak (which can be caused by a loose gas cap, among other more permanent causes) and you fixed it! An illuminated MIL (malfunction indicator lamp) caused by this fault will remain on until three consecutive good trips. (A聽good trip is a specific driving sequence where the diagnostic monitor runs to completion without incident.) Depending on one鈥檚 driving habits and refuelling regimen, clearing the light might take some time. I鈥檓 hoping this wasn鈥檛 an intermittent fault caused by something else and the light turned off by coincidence.
Brad Bergholdt is an automotive technology instructor at Evergreen Valley College in San Jose, California. Readers can email him at [email protected]; he cannot make personal replies.
