Northstar Engines and System Technical Discussion Discussion, 99 STS Engine Temp Sensor problem in Cadillac Engine Discussion; I have a 1999 STS with 104k miles. I have had a check engine light and went into the OBDII ...
- 07-31-05 06:25 PM #1Cadillac Owners Member
- Join Date
- Jul 2005
- Fargo, ND
99 STS Engine Temp Sensor problem
I have a 1999 STS with 104k miles. I have had a check engine light and went into the OBDII through the DIC and found its caused by the engine temp sensor. I am now looking for it on the engine and cannot find it. Any help? Also, I found something interesting when I was in Diagnosic mode on the DIC. When I was looking at the PROM ID's, it shows my PCM is not supported, when it is supposed to be telling me the number for the PCM. Is this normal? I bought the car used, and now am wondering if the PCM has been replaced and itsn't programmed or something. All of the other systems checked out though, and they displayed their numbers on the DIC. Any help would be greatly appreciated!
- 07-31-05 07:25 PM #2
Re: 99 STS Engine Temp Sensor problemOriginally Posted by dlueker
Do you have the remote key fobs for door lock/unlock and trunk and fuel door release? Do they work? Your ignition key does have the resistor pellet in it, right? It's possible the PCM was replaced at some point and not programmed exactly right. It could be missing calibration data perhaps. I don't know enough about it to tell you what other problems there might be, and our resident expert b b o b y n s k i is apparently on "sabbatical."Mike
- 07-31-05 10:14 PM #3
Re: 99 STS Engine Temp Sensor problem
The ECT (engine coolant tempurature) sensor is located on the rear (driver side) of the right (rear) cylinder head.