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Code Reader Problems, Please Help, Assistance Needed


Jamison350
06-11-2005, 08:12 PM
My electric fans do not work, so I bought a Helms manuel to check it
out myself.

After going through the trouble shooting section on the cooling fans,
it tells me to first check the "PCM DTC codes". So I buy one of those
code readers from Kragen, and plug that thing into the connector
underneath the dash--but I get nothing... not even code 12 like the
code reader manuel says I should get-- but the primary fan do turn on, but nothing else, not even the engine code light blinks or anything. When I start the car with the code reader inserted-- then the check engine light blinks-- nothing more though, just blinks in the same monotoneous fashion.

I looked up this problem in the Electrical section of the Helms manuel
(A problem with non-code showing), but I got nothing again... not even a section on it. So it seems to me that I have a problem with the part of my car that checks problems (HUGE paradox, this stuff happens to me all the time though). So before I fix my fans I need to fix this PCM DTC problem. What is a 94' 9C1 owner to do?

I know my horns did not work when I first got the car, and upon
investigation I found there was some disconnected wires underneath the dash that led to the problem. The source I bought the car from did a 'snappy' job of dissconnecting all the old police equipment I think. Maybe this would explain my code reader problems?

Does anybody have a diagram on how the reader connector should be
connected? Maybe I could trace the wires and ensure that it is wired
up right. I don't know, give me some insight! I need some clues or
suggestions to push me in the right direction. All else fails then I
will just take it into the shop, but electrical problems are usaully
scary fixs because the hours they can 'suggest' it took to do.

Jamison350
06-12-2005, 06:31 PM
I pulled this off of the 9c1 Forum. Might be usefull information it somebody else runs into the same problem as me. Thanks to Peter Cordes (9C1 Forum):

"Well Mr Jamison, this is going to be a quick reply.
First off, 94+ cars don't work with those cheapie code
readers or the famous paperclip method of diagnosing
GM cars. To read codes on a 94+ you need a real code scanner like a Tech-1 or a cable and software for a computer to read the codes. On the fan problem itself, its probably an electrical issues somewhere in the fan circuit. Check the fuses, check for any visible wire breaks, it could even be a bad fan relay. A quick
check would be to turn on the AC and see if the fans
come on. If they do then that rules out all the above,
but if they don't keep checking. To check the relays
take them out and jumper the socket between the relay
switch contacts(NOT THE COIL CONTACTS, read the relay to see which contacts are where to prevent other damage to the car!!!). If the fan(s) come on when jumpering the relay socket then you probably found your problem. Also the PCM of your car is most likely fine so don't really worry about that. Hope that helps clear some things up a bit for you. - Peter Cordes"

radioman2002
06-14-2005, 07:33 PM
Most cars older than 1998 won't work with the cheap code readers, because they are not true ODB II, as the 94 is. The 94 is a hybrid of OBD I and II.

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