: Running on 4 Cylinders..not in Overheat mode



95_Aurora
01-02-12, 03:43 PM
My Aurora had a clogged injector. Replaced injector and the check engine light came on. The fuel injector harness was shorting out to a intake bolt. Taped up the harness and undid the battery. The the Aurora would only run on the front 2 outside cylinders and the rear middle cylinders. The trouble code says a short in the fuel injector circuit. So I replaced the fuel injector harness, all injectors ohm fine, and replaced the PCM. Still won't run on all 8. Anybody else know why it would only want to run on just 4 cylinders and still have that code? It is like the overheat limp home mode except it does not switch which 4 cylinders it is running on.

Submariner409
01-02-12, 04:09 PM
Those cylinders - 2,3,5,8, - are the two right hand coils on the ICM. Something's fishy there.

95_Aurora
01-02-12, 08:24 PM
Well after the dealership soaked me for 90 dollars in labor and 8 dollars for a fuse, turns out that the fuse was blown for the 4 non squirting injectors. I checked them before, should have again. Now I have more problems as I can't get the new PCM to learn the TPS. I thought the dealership would have done it for me for that 100 dollar bill for a fuse but they didn't :/

89falcon
01-02-12, 08:49 PM
Well after the dealership soaked me for 90 dollars in labor and 8 dollars for a fuse, turns out that the fuse was blown for the 4 non squirting injectors. I checked them before, should have again. Now I have more problems as I can't get the new PCM to learn the TPS. I thought the dealership would have done it for me for that 100 dollar bill for a fuse but they didn't :/

why not put the old pcm back........

Ranger
01-02-12, 10:53 PM
After reading post #1 I was just about to suggest the fuse, which should have been obvious after a short circuit. Then I saw post #3.

Doesn't it relearn on it's own after a few days?

95_Aurora
01-02-12, 11:06 PM
Old PCM was turned in as a core to the parts store. But no they never will relearn the tps on their own. The procedure is a bit easier for Caddys with the diagnostic mode that the Aurora does not have. Procedure from a post on ACNA:

1. Engine off, turn ignition to on
2. Turn ign to off
3. wait a min of 20 seconds
4. Turn ign to on
5. Turn ign. to off
6. Wait a minimum of 20 seconds
7. Turn ign to on
8 . Turn ign to off
9. Wait 20 seconds

Then do the idle learn procedure:

1. Start the engine and let it idle until the temp reaches 176 degrees, then idle it an additional 5 minutes.
2. With the gear in park, briefly accelerate the engine to over 1500 RPM
3. Return to idle
4. Apply the brakes, put it in drive, and idle it for two minutes or until the check engine light goes out.

tateos
01-03-12, 06:02 PM
If it were me, I would have been happy to pay $98 to get my car running on all 8 cylinders again...and a little annoyed at myself for not figuring it out on my own.

95_Aurora
01-04-12, 08:12 PM
Well it's still not fully running all the way, two clogged injectors and the TPS won't set. Regardless my car wasn't even there for an hour and they first only quoted me only a half hour of labor. You don't charge somebody a full hour to change a damn fuse that's not even a half hour job and you don't charge somebody for a 9 dollar fuse when they have a spare in the holder

94CaddyConcours
01-10-12, 01:20 AM
After the initial inspection they should've have ask you if you want the work to be perform before replacing the fuse. :helpless: