89 Olds 88 Code 41

[technovative]

I'm working on an 89 Oldsmobile Delta 88 with the 3.8 V6. About 2 years ago the car started running poorly so I checked for trouble codes and the ECM returned code 41 (cam sensor). I did some investigating and found that the cam sensor interrupter (magnet) had broken off the cam gear. I replaced the interrupter, and the sensor and it resolved the problem. Last week the car started having similar symptoms so I checked for codes and again got code 41. I assumed that the magnet had broken off again so I removed the sensor to check and found that the magnet is intact. I swapped the sensor with another one that I have and I'm still getting code 41. I'm thinking that the timing chain may be the culprit as the car has over 150,000 miles on it and the timing set hasn't been replaced. Is anyone aware of code 41 being triggered falsely due to a worn timing chain?

[HotZ28]

Code 41 can also indicate the crank position sensor is defective. The timing set has nothing to do with crank position, however it does effect cam position.

[technovative]

HotZ28, thanks for the response. Just to clarify when I wrote that the timing set hadn't been replaced I was reffering to the chain and sprockets. My thinking is that if the timing chain has developed to much slack that this may cause the cam sensor signal to be out of sync possibly triggering the code 41. I have read some information supporting the possibility that this can happen. You suggest that the crank position sensor can trigger the code, do you know of a method of testing the sensor?

[HotZ28]

Actually, in addition to the possible CKPS malfunction, a code 41 indicates that the cam sensor signal was not received by the PCM for the last 5-seconds while engine was running! A little slack in the chain will not cause a 5-second delay.

[technovative]

Well, it's not the crank position sensor. I replaced it and the car still runs roughly and I'm still getting a code 41. Also I didn't mention it previously but the car has stalled while being driven a couple of times recently and it doesn't want to start back up. I agree that slack in the chain isn't going to cause a 5-second cam signal delay. But I don't see how a malfunctioning crank sensor is going to cause a 5-second delay in the cam signal either. I have a spare coil pack/ignition module that I'm going to try out to see if it may be the problem.

[technovative]

Problem solved! It turned out to be the ignition module. When i removed the wiring harness connector from the module the resin that encapsulates the module circuit board was oozing out of the connector. So for anyone experiencing similar problems a code 41 can indicate a bad ignition module. Even though the generic description of a code 41 is that the cam position sensor signal was not received for the last few seconds that the engine was running.