On Board Diagnostic Module


I have been told that the reason my 1999 Olds Intrigue displays the “Service Vehicle Soon”, “Anti-Lock Brakes” and “Traction Off” warning lights is a malfunction of the “diagnostic computer”. I assume this means the OBDM. Is mine a correct assumption? If it is, can the OBDM be replaced by a very average “DIY”-er equipped with a Haynes service manual? Finally, should the unit be replaced with a brand new unit, or can I go to a parts recycler (junkyard)?


I cannot tell you if your computer is defective. Hopefully you have the factory service manual which will give you some troubleshooting flowcharts, and you can verify (or reject) this notion.

I have done a few computer transplants on Dodge cars.
So easy even a caveman…

You simply disconnect the electrical connector, unbolt the old one and bolt on the replacement. No special precautions are required, although it is usually prudent to disconnect the battery for such operations.

You don’t need to buy new. I bought a used PCM online from a fellow who had upgraded his car with a performance computer so he had a spare OEM unit. Make sure it’s from an identical model – you can’t successfully transplant a unit from a car with auto transmission into one with manual transmission, and so on.


I think you may have two diffrent issues going on here. I would take your car to one of the car parts store that pulls your CEL codes for free and see if there are any codes set and post them here. My daughters car would set off the Traction Off Light when there is a CEL. You could have problems with your engine managment system and your anti-lock brake system.

If I might ask who told you that you need to change your “diagnostic computer” which I’m thinking is your ECM. Did they do any testing to your car to come up with this diagnosis?


Sounds to me like you may have, at least, a bad wheel sensor or something. That would make the ABS and traction control lights come on. Oh, it might even be a vehicle speed sensor, that could cause all three lights. I don’t know why you jump right to a failed computer module. Seems like you should get the codes scanned and see what they are trying to tell you first.