Computer went crazy after new battery...
Thread Starter
Burning Brakes
Joined: Jan 2002
Posts: 885
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From: Long Island NY
Computer went crazy after new battery...
Well I finally got around to putting in my battery tonight...and I went to start it up. As soon as I put the key in and turned it to ACC power, the "Corvette by Chevrolet" computer screen lit up like usual, and all the gauges went to max and then back down again...the first weird thing I noticed was that my lights were off, but the center console lights (radio/HVAC) were on, which never happened without the exterior lights on. Also, upon starting the car, the whole gauge cluster went dead, with no lights or gauges responding. The DIC screen just read all "AAAAAAAAAAAAAAAAAAAAAAA" adn wouldn't respond to anything I did. I turned the car off, and back on again, with the same result. Radio and climate control work fine, exterior lights work fine, and the engine runs fine (needs to relearn idle etc.) but I'm not sure what to make of the gauges. Any help is appreciated...thanks in advance
-Pete
-Pete
Melting Slicks
Joined: Jan 2001
Posts: 2,635
Likes: 2
From: Aloha, Oregon
Re: Computer went crazy after new battery... (Pete99SS)
This is a common thing after disconnecting power. remove the PCM fuses (fuses 16 and 23, i believe), then disconnect the battery for about 10 minutes. Reconnect, reinstall fuses, try again.
Get in the habit of removing the PCM fuses before disconnecting the battery; the arcing sometimes accompanied with removing battery power can damage the PCM's.
Get in the habit of removing the PCM fuses before disconnecting the battery; the arcing sometimes accompanied with removing battery power can damage the PCM's.
Thread Starter
Burning Brakes
Joined: Jan 2002
Posts: 885
Likes: 0
From: Long Island NY
Re: Computer went crazy after new battery... (rwj383)
Thanks a bunch, problem solved....after relearning idle and driving her around she just fixed the problem herself it seems...everything is working fine now, and i'm happy to be driving her again :D
-Pete
-Pete
Le Mans Master
Joined: Mar 2002
Posts: 5,718
Likes: 2
From: Flower Mound TX
Cruise-In V Veteran
St. Jude Contributor
Re: Computer went crazy after new battery... (Pete99SS)
Just curious...you mentioned idle relearn a couple of times. The PCM should not loose it's memory, correct? Why would it need to do an idle relearn?
Just curious, thanks.
Just curious, thanks.
Melting Slicks
Joined: Jan 2001
Posts: 2,635
Likes: 2
From: Aloha, Oregon
Re: Computer went crazy after new battery... (C5 StockSwap)
there are certained 'learned' parameters that are held as static memory only. STFT/LTFT averages, for instance, are lost and have to be relearned through driving. this is a very basic and quick explanation of this. Charles Probst's book on Corvette Fuel Injection is a good source to understanding this.
[Modified by rwj383, 9:30 AM 12/8/2002]
[Modified by rwj383, 9:30 AM 12/8/2002]
