92 LeSabre...PLEASE HELP

[chacha2008]

After reading some of the posts I notice that this is not an uncommon issue.
My LeSabre starts fine but depending on the outside tepmature it runs rough and my check engine light comes on. When its mid 80's it will run fine, once the car runs a while and heats up the rough running starts back up. I feel as if the car is out of time and studders when I hit the gas.

I took the car to Firestone and they hooked it up to their machine. Came back with a code 42, same code I got using the paper clip method. They told me that I had a bad Ignition Control Module, I picked up the car and switched the module myself with a new one. Problem still persists, changed the module again (thinking the new one was bad), still no luck.

I know that this code will appear with various issues and it's a hit or miss trying to narow the probelm down. I am begining to think it may be my MAF sensor??? I realize this may take a while to figure out exactly what the problem is, but any info will help. Any ideas??????

[spinne1]

Originally Posted by chacha2008

After reading some of the posts I notice that this is not an uncommon issue.
My LeSabre starts fine but depending on the outside tepmature it runs rough and my check engine light comes on. When its mid 80's it will run fine, once the car runs a while and heats up the rough running starts back up. I feel as if the car is out of time and studders when I hit the gas.

I took the car to Firestone and they hooked it up to their machine. Came back with a code 42, same code I got using the paper clip method. They told me that I had a bad Ignition Control Module, I picked up the car and switched the module myself with a new one. Problem still persists, changed the module again (thinking the new one was bad), still no luck.

I know that this code will appear with various issues and it's a hit or miss trying to narow the probelm down. I am begining to think it may be my MAF sensor??? I realize this may take a while to figure out exactly what the problem is, but any info will help. Any ideas??????

Problem one right there. I've had nothing but trouble at Firestone. I feel they are incompetent. After I had a wheel alignment there, the car pulled the EXACT same as before I went in and they claimed it couldn't be fixed due to a "loose inner tie rod." Yeah, right. If the inner tie rod WAS loose, it would track correctly SOME of the time if aligned properly, but mine didn't. I said screw them and never went back. This was about the third time I've been unhappy with Firestone service.

As to your problem. According to the manual, code 42 is set when:

Open or ground CKT 423 at time of engine start up (white wire in position A from ICM harness that eventually leads to BC7 on the PCM--called "EST" position)

or

PCM commanding bypass mode (open or grounded CKT 424) at time of startup. (tan/black wire from position B from ICM harness that eventually leads to BC6 on the PCM--called "bypass" position)



Ultimately you could have bad wiring, a bad ICM, a bad PCM, or a poor connection at a harness.

I hope this helps somewhat.

To really dig into this you need an official manual for this vehicle. Your specific problem flow chart is on page 6E3-A-75. You can get the manuals on ebay generally or new for about $100. There are two manuals total that make up the complete manual.

[chacha2008]

Wow thats a start!
Funny thing is Firestone gave me a 2 page info sheet on code 42 and didnt mention anything other than its hard to figure out what the main problem.
Thanks for the help, I'll check all you mentioned. Starting to believe that I may just have to get rid of the car, might cost me more to fix than its worth.

[spinne1]

Originally Posted by chacha2008

Wow thats a start!
Funny thing is Firestone gave me a 2 page info sheet on code 42 and didnt mention anything other than its hard to figure out what the main problem.
Thanks for the help, I'll check all you mentioned. Starting to believe that I may just have to get rid of the car, might cost me more to fix than its worth.

Not if you do the work yourself and get the parts from a pick and pull junkyard. I could fix your car for way under $100 even if I simply blindly changed parts out. I think you should get a multimeter/ohmmeter and test the wires I mentioned above to check for voltage/open/ground/continuity.