Quad Driver

[john266]

OK, for the first time since I have owned my 91, the check engine light came on today. I took the car and got the codes read at Advance Auto Parts, and I am getting 2 error codes. One code is a code 26, which says there is a QDM fault (quad driver). The other code that came up was a code 31 (PRNDL Switch circuit problem). When I had the tranny rebuilt about a year ago (the 91 being the only year with the electronic tranny), I started have occasional problems with the torque converter locking in at low speeds. The mechanic who did my trans work said one of my quad drivers was going bad in the ECM when I asked him about the torque converter locking in and out at low speeds going down the road.

Has anyone ever had this problem? If so, do I need to replace my computer? My guess is I need a new computer, but if it is the computer that is bad, I dont know where it is located in the car.

If anyone can offer some advice I would appreciate it.

[Jim]

John,

I have a good computer for your '91 and I sent you an email.

The ECM is located under the glove box and is mounted vertically next to the heater programmer. You will need to remove the glove box and the panel under the glove box to get at it. It is silver and has three large connectors on it.

Jim