Gm Trouble Code Question

[kdaddy]

I need some help for my other car- not my Caddy its my Buick.

My 1993 LeSabre has an engine trouble code 17 reading.

Manufacturer Specific Definition:

code 17 : crank signal circuit OR ECM fault crank position sensor circuit (3.8L)

Here is what happens

I can be driving than suddenly my vehicle will just stall. I will have to wait for 5 to 30 minutes before it can start again. on other occasions the car won't start at all, the engine just turns and turns. this happens out of the blue. sometimes it will occur 3 times in a day and other times it will happen every few weeks. So my question is should I think about A. Checking the wiring from the Crank sensor to the ECM. B. More likely replace the Crank sensor. or C. Replace the ECM. Please help.

[jhall]

Unless you've been working on the car and may have pulled something loose in the harness, it's probably a failing crank sensor. Stalling is a classic condition of one that wigs out after the engine gets hot.

The sensor tells the ECM the position of the crankshaft so it knows when to fire the plugs for each cylinder.

Replace it and then worry about the ECM if the condition reoccurs.

Not sure exactly where the LeSabre sensor is located, but maybe some of the other Caddy guys with info on a LeSabre can help.

Good luck!

[Logan]

Hmmm...know the car well. Same engine as my old '92 bonneville.

I think you have answered your own question..

Check the connection first.

If OK

Suspect bad crank senor.

If OK...I would 'look' at the PCM rather then just throw one at it.

Buick 3800 known problems.

The crank sensor is behind the crankshaft hub/balancer. They live a pretty tough life there. Also there is wiring there getting exposed to the elements etc.

If the wires, connections, and sensor are ok...then start thinking about the PCM.

You are at the perfect age vehicle for a PCM failure. 10-12 years. Often times its when the PCM gets warm the failure mode happens. Sounds a bit like yours...

One trick is to drop the PCM. Then while the car is running. Tap test the PCM in different spots and see if you can induce a stall, check engine light, stumble type issues.

Any funny business while tapping indicates a bad PCM. You can often find one spot...everytime you tap that spot...it will stall..

[Phillip]

I went through the same thing with my 93 3.8 liter APV. Logan hit the nail on the head. In my case it was the crank sensor, but it is worth checking the PCM first. It is not a difficult test. Good luck.

[kdaddy]

It was the CPS just like Logan said. Thanks

[MAC]

My brother's 92 Park Avenue (3.8L) had the same problem. The crankshaft sensor probably needs to be replaced. From what I understand the faulty sensor is incorrectly sensing crankshaft rotation in degrees, thus ignition timing is way off. As a result, the car stalls. My brother's car also stalled when it reached operating temp. He would be driving then all of a sudden the car would just stall--no warning.