System error code diagnostic process
Thread Starter
Racer
Joined: Apr 2003
Posts: 365
Likes: 0
From: Cupertino in Northern California
System error code diagnostic process
My L98 is showing the "sys" indicator. I have read the threads
on how to obtain the error codes. Being a non-techie I was not
surprised when I was not even able to obtain the initial 12 code.
When I shorted a&b with the key turned on but the engine not
running, it sounds like the fan starts up. From there I only see
the "sys" flashing and stopping in the same pattern/timing as when the
engine is running. No numeric codes are showing. I had the pins
shorted through the entire process.
Maybe I did not have the pins completely shorted ? Any thoughts
with my limited information. Sorry to :beatdeadhorse: with this
post but I prefer to identify the codes prior to bringing the car
into a service shop. Car has only 11k so I am miffed.
Plus I want the car running smoothly in time for the Hooters opening
in the east bay :D :D :D :D :D :D
All assistance is greatly appreciated.
:seeya
on how to obtain the error codes. Being a non-techie I was not
surprised when I was not even able to obtain the initial 12 code.
When I shorted a&b with the key turned on but the engine not
running, it sounds like the fan starts up. From there I only see
the "sys" flashing and stopping in the same pattern/timing as when the
engine is running. No numeric codes are showing. I had the pins
shorted through the entire process.
Maybe I did not have the pins completely shorted ? Any thoughts
with my limited information. Sorry to :beatdeadhorse: with this
post but I prefer to identify the codes prior to bringing the car
into a service shop. Car has only 11k so I am miffed.
Plus I want the car running smoothly in time for the Hooters opening
in the east bay :D :D :D :D :D :D
All assistance is greatly appreciated.
:seeya
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
Re: System error code diagnostic process (90coupewithlowmiles)
You won't see numbers, you have to count the flashes.
One flash followed by a pause then two quick flashes indicates code 12, which is a normal code. This will repeat two more times for a total of three times.
Then any error code that is stored will begin to flash: say four flashes, then a pause then two quick flashes: indicates code 42.
That will also flash three times, then the system moves on to the next stored code, if there is one.
When all the stored codes have been flashed, code 12 will continue to flash until you turn the ignition key off and remove the jumper.
Jake
One flash followed by a pause then two quick flashes indicates code 12, which is a normal code. This will repeat two more times for a total of three times.
Then any error code that is stored will begin to flash: say four flashes, then a pause then two quick flashes: indicates code 42.
That will also flash three times, then the system moves on to the next stored code, if there is one.
When all the stored codes have been flashed, code 12 will continue to flash until you turn the ignition key off and remove the jumper.
Jake
Thread Starter
Racer
Joined: Apr 2003
Posts: 365
Likes: 0
From: Cupertino in Northern California
Re: System error code diagnostic process (JAKE)
Thanks for the info. I still have 2 more hours of daylight here
on the left coast to identify whether there are error codes.
on the left coast to identify whether there are error codes.
Pro
Joined: Oct 2003
Posts: 732
Likes: 2
From: Baxter MN
Re: System error code diagnostic process (90coupewithlowmiles)
Hi,
There is a different pin used to determine what "sy"' code has been triggered. Grounding A to B will give you the ECM codes. I have tried to find which other pin you need to ground, but I just can't recall. Perhaps someone else can help. Also, be extremely careful that your ignition is off if you decide to disconnect the negative battery cable. If you accidentally leave it on you could easily fry your ECM unit. Finally, Disconnecting your battey negative cable may NOT clear your codes. It did nothing for me. Nor was GM able to clear the code. I don't know what actually clears the code. Hope this is somewhat helpful.
Glen
There is a different pin used to determine what "sy"' code has been triggered. Grounding A to B will give you the ECM codes. I have tried to find which other pin you need to ground, but I just can't recall. Perhaps someone else can help. Also, be extremely careful that your ignition is off if you decide to disconnect the negative battery cable. If you accidentally leave it on you could easily fry your ECM unit. Finally, Disconnecting your battey negative cable may NOT clear your codes. It did nothing for me. Nor was GM able to clear the code. I don't know what actually clears the code. Hope this is somewhat helpful.
Glen
Le Mans Master
Joined: Jul 2002
Posts: 5,818
Likes: 2
From: Alive and well in Burlington NC
Re: System error code diagnostic process (90coupewithlowmiles)
Since you have a 90, you can short the A and G pins to display the codes. Here's a link to the procedure:
http://www.c4vettes.com/codes.htm
http://www.c4vettes.com/codes.htm
Burning Brakes
Joined: Dec 2002
Posts: 1,199
Likes: 4
From: Cairns Australia
Re: System error code diagnostic process (olefam)
Shouldn't you ground A and B THEN turn on the ignition ? or doesn't it make a difference.
The ECM codes should definitely disappear when the battery is disconnected
I'm no great expert but I think that if the codes don't clear, then either the fault still exists so the codes are retriggered (but you think they'd be gone untill the engine was re-started)
Or - a back up battery has been fitted by a previous owner, perhaps behind the centre facia panel.
S'nut
The ECM codes should definitely disappear when the battery is disconnected
I'm no great expert but I think that if the codes don't clear, then either the fault still exists so the codes are retriggered (but you think they'd be gone untill the engine was re-started)
Or - a back up battery has been fitted by a previous owner, perhaps behind the centre facia panel.
S'nut
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
Re: System error code diagnostic process (Stingraynut)
On a friend's 86 (same year as mine) I had to leave the battery disconected for well over a minute in order for his error codes to clear.
Mine clear in only a few seconds - Go Figure.
Jake
Mine clear in only a few seconds - Go Figure.
Jake
