'92 3.3L Olds Cutlass Ciera, intermittent code 42, bad stumbling
Bert Hochwald
1992 3.3L Olds Cutlass Ciera w/55K miles
Today I was driving in 40-50 degree humid weather with the AC on to clear up
my windows, and the car ran fine. But, after about two miles I stopped
for gas, and, when I restarted, the car stumbled and had very low power.
The SES light came on, and I stopped and started the car two more times
with no improvement. However, after the fourth start, the car was
suddenly cured, the SES light went off, and away I went. The problem hasn't
reappeared today, but I don't want to wait until it does since the car was
basically undrivable when it was stumbling.
1) When I got home I read the diagnostic code from memory to be '42',
meaning 'Electronic Spark', or 'Ignition Module'. I fooled around a
little with what I thought was the module (is this the part with the 6
coil packs attached?) and wiggled all connections with engine running,
but no effect. Anybody had this problem happen to them? By the way,
where is the ECM? Behind the glove box? Did I freeze it with the AC?
2) My Chilton book says that to clear the codes in the ECM that I can
remove the ECM fuse for a few minutes and replace. I tried this, but
when I go into diagnostic mode the code '42' is still there. The SES
light remains off though, so no new codes are being set. How do I really
clear the codes?
Thanks,
Bert
John Lamb
Try clearing the codes by pulling the ecm B fuse. Sometimes there are more
than one ECM fuse. If you can't find the right one, disconnect the battery
to 15 seconds. Then see if the code resets. The AC should have had
nothing to do with it. Why did the light come on in the first place? Code
42 is one of the most commonly set unexplained glitches. If it comes back,
then worry about it. Meanwhile, get that code reset so that you will know
if it reappears.
--
-----------------
John Lamb
25 year ASE certified Master Mechanic +L1
Mechanical Investigation and Expert Witness Testimony
Lambs Automotive
Lincolnshire, Il.
847-821-2100
http://www.lambsauto.com
jo...@lambsauto.com
Bert Hochwald <hoch...@flood.ucsd.edu> wrote in article
<Pine.HPP.3.91.97012...@flood.ucsd.edu>...
Otto Matheke
Bert Hochwald wrote:
>
> 1992 3.3L Olds Cutlass Ciera w/55K miles
> Today I was driving in 40-50 degree humid weather with the AC on to
> remove the ECM fuse for a few minutes and replace. I tried this, but
> when I go into diagnostic mode the code '42' is still there. The SES
> light remains off though, so no new codes are being set. How do I really
> clear the codes?
>
> Thanks,
> Bert
Some ECM's have a capacitor that will store enough electricity to keep
codes in memory for 24 hours even when the battery is completely flat.
To clear the codes on such vehicles you need to be sure the key is in
the off position and disconnect BOTH battery terminals and touch the
positive cable to the negative to discharge the capacitor. BE
COMPLETELY SURE that the battery is completely disconnected and there is
no electrical supply to the car when you do this.
--
Otto Matheke
omat...@nhtsa.dot.gov
All statements or opinions offered above are my own and not those of the
National Highway Traffic Safety Administration, the Department of
Transportation, or the United States Government (which was foolish
enough to give me e-mail capability)
John Lamb
That process is a good idea to clear long term adaptive strategy, but is
not necessary to clear GM trouble codes, and may be some trouble, since if
you clear adaptive strategy, you will have to go through a certain amount
of retraining. If you are trying to clear adaptive strategy, you can
accomplish the same thing by stepping on the brake pedal while the battery
is disconnected. This effectively does the same thing as touching battery
cables together, since both circuits are always wired battery direct.
--
-----------------
John Lamb
25 year ASE certified Master Mechanic +L1
Mechanical Investigation and Expert Witness Testimony
Lambs Automotive
Lincolnshire, Il.
847-821-2100
http://www.lambsauto.com
jo...@lambsauto.com
Otto Matheke <omat...@nhtsa.dot.gov> wrote in article
<32EE55...@nhtsa.dot.gov>...
Care...@earthlink.net
Scott Dorsey
>1993 Grand Am 3.3L V6 (6-204) - Solved intermittent "Code 42 - electronic =
>spark timing" issue by replacing Mass Air Flow sensor, after checking all w=
>ires in harness (and replacing some) between the ECM and ICM, checking all =
>connections, and replacing all the other sensors. All work prior to replac=
>ing MAF improved performance but did NOT solve intermittent Code 42 problem=
throttle and were there any dropouts?
Does the MAF sensor by any chance share a reference ground in a cable with
something else? If something bad in the MAF sensor electronics was polluting
the ground, you could have seen spreading problems like that.
I have to say that's a hell of a weird one. I'm very curious what the
failure mechanism was.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
