I had some problems with the ignition module on my 88 bonnevile that lead me to replace the crankshaft sensor and camshaft sensor with new ones and I also have put in another magnovox module and coilpack from a local junkyard here. I didnt replace the camshaft button because it looked like it was in great shape with no wobble or looseness to it.

The car is running great now, but I am still getting a code 41 and a code 43 when I jumper the diagnostic port, which after some searching on the web I found that 43 identified "Electronic Spark Control (ESC) Circuit". I already knew 41 means cam shaft sensor from here on the forums..

Am I supposed to do something after I fix the problem to make the light go away? Could a problem still exist, even though its running fine? During the ignotion problem i was having, I closely inspected every wire in the harness and meticulously put it back in place to eliminate a short in the wiring, so I am certain the wiring is not the cause. The harness was in excellent condition and still is..

I cannot remmeber exactly what kind of car the module came off of at the junkyard, I just know it wasnt a pontiac. I do know that the car was in excellent shape and once I put that module in, it started right up. and has ever since.

Could it be that cam button, even though it looked ok? Could it be the module? Could it be just me and my bad luck with this damn car?

Any help or suggestions would be muchly appreciated.

Keep in mind that the cam position sensor is routed through the ignition module before it goes to the ecm. The signal is not used there it just goes in one pin and out another. There could be a problem with the connection or even the icm is still faulty.

As for resetting the codes, just disconnect the battery for a few minutes and then reconnect.

I tried disconnecting the postive terminal from the battery and it didnt work. I've heard that the light will go off on its own eventually, once the problem is fixed. Any truth to this? Maybe I didnt leave the battery disconnected long enough? If I rememebr correctly, I believe I only took it off for about 30 seconds then replaced it.

Leave it off for a good 3 to 5 minutes.

Im bout to go tinker with it in a few and I will try it.

thanks for the reply.

My service engine light on my 91 Bonneville SSE stays on too. The guy who sold me it said its been on for years and that they took it to numerous places and had it checked for problems, and only major problem i had with it was the fuel pump went. They said an or claimed they took it and had the computer plugged into a diagnostic machine and no codes came up. So they just covered it with electrical tape on the dash so b/c they were tired of lookin at it. I might go have it plugged in an auto zone just to double check.

I have had my bonnie for a year now and I owned a 91 regal with the 3.8 prior to this and I have found that the first thing to do is to get the codes read. Once you have the codes there are plenty people on here that can help. There is always a reason for the light, not always a person wiling to put it out.

Here are a couple of tech links to help you out.

Code list
http://www.bonnevilleclub.com/forum/...e=article&k=68

How to read the codes
http://www.bonnevilleclub.com/forum/...e=article&k=57

If you are going to troubleshoot your light be shure to start your own thread to prevent confusion and so we can help each other.

I'm not sure if this is directed to me or the person above your post but I was getting a code 41 and a code 43.

41 - Cam Sensor Circuit
43 - Electronic Spark Control Circuit

Also, I disconnected both pos and neg terminals on the battery for an hour and the light still came on. It did, however, go off initially after it cranked for about a second before it came back on like it had reset and then it found the problem and the light came back on. When before it usually comes on immediately after the motor is cranked, thus leading me to believe that it did reset, but there is still a problem... even though I dont know what to do other than go buy a brand new module for 130 bucks., This wouldnt be too bad but Ive spent close to 500 dollars already fixing stuff that wasnt broke to get it running in the first place. This car is severely pissing me off >:(

Did you check the wiring from the cam sensor to the icm and then from the icm to the ecm? The wire from the cam sensor goes from the sensor to the ignition control module to the ecm. The icm does nothing with it.

I had my drive belt cut into my harness right under the alternator and it gave me a code 41 before. It had cut the wire from the sensor to the icm.

Cam sensor wires:

brown and white into ICM connector on pin J
out black wire on pin F

Use a meter and measure the resistance from pin A on the cam sensor connector to pin j on the ICM.


The code 43 points to the knock retard sensor.
Plug the ICM back in and then measure from pin A on cam sensor to the back side of pin F on the ICM connector.

This will verify the wiring from the cam sensor through the ICM.

PM sent