Questions and Answers

Cadillac DeVille Has A Problem Q. I have a 1990 Cadillac DeVille. I get an occasional error code 41. The car runs fine till the engine light comes on, when the light goes off it is fine. The light when it comes on wants to stall or mis-fire. It does not do it all the time the first start up in the morning it will run all day okay. It is when you start it again that the problems happen.

The code 41 is the Camshaft Position Sensor (CPS). My question is it or doe's it sound like it is faulty and if so can it be changed without going into the motor? I was told it is on the front of the motor by the serpentine belt. Also I do think I have a bad fast idle control (this is what I call it). It is on the left side of the TBI and sometimes pulsates when you shut the engine down like a tap, tap, tap. I checked it and it has steady volt to it but think it is going.

Can this be a CPS causing the engine to want to stall or is something else going on? The only code coming up on the computer is 41. I had giving it a tune up new O2 sensor and catalytic converter Any help?

A. The cam sensor is located on the distributor shaft and provides one pulse per rotation of the distributor. The PCM/ECM uses the cam sensor signal to determine the location of the camshaft for proper fuel distribution. Code E41 sets when the PCM/ECM is receiving reference pulses and does not detect any cam sensor pulses. To replace the CPS:

Remove or Disconnect:

1. Ignition switch battery feed wire from distributor cap.
2. Ignition coil connectors from distributor cap.
3. Four (4) retainers on distributor cap and move cap out of way.
4. Six terminal PCM harness from distributor.
5. Distributor clamp nut and hold down clamp.
6. Note position of rotor, then pull distributor up until rotor just stops turning counter clockwise and again note position of rotor.
7. Remove distributor.

Install or Connect:

1. Distributor with rotor in same position as noted in removal step 6.
2. Hold down clamp and distributor clamp nut lightly snug.
3. Six terminal PCM harness.
4. Distributor cap.
5. Four (4) retaining bolts.
6. Ignition coil connector to cap.
7. Ignition switch battery feed wire.
8. Adjust ignition timing.
9. Tighten distributor hold-down nut.

The one the front of the engine by the crankshaft pulley is the Crankshaft Position Sensor.