Ok, so originally I was out to get the codes for my car the 95 cavalier with obd1 with ob2 connector finally after a long period of time i finally got them read. Originally it was only code 35 (idle speed error).
With tuner pro rt my rpms were being measured at between 1100 and 1250 rpms (thus setting off the light). I then replaced my upper intake gasket with a new one after finding part of the old gasket had broken down from age. After gasket replacement, my idle speed went down to the normal 650 rpms and the engine was now running correct and the check engine light immediatly went away (yeay!)

When I was putting the upper intake stuff back together I couldnt figure out where the throttle valve cable was supposed to reconnect to, so I left it off till I could either figure it out or post it in the forums which I did. I then took the car for a test drive (about an hour and a half) and ran into some problems that you might expect with the tv cable disconnected (flaky shifting) but no codes were being thrown and the check engine light did not return. I took the car out 3 times after this (short trips) and not once did the check engine light return (even after reaching full operating temp). Yesterday, I finally figured out where the T.V. cable mounted to and promply reconnected it. I then took it for another test drive to see if the flaky shifting went away and it had, but now the check engine light has returned, (almost within minutes of the cable being re-attached). This time I have a code 27 quad driver module 1 circuit.

My question is specifically what components are being controlled by that specific quad driver unit? ,(keep in mind it is a 95 cavalier with obd1), Which components on that quad would ACTUALLY trigger the check engine light (for example, if one of the features that the quad controls or monitors is cruise control and you dont have cruise control then obviously not having a sensor reading from that non-existant component would not trigger a check engine light because it doesnt have that particular component to begin with), and has anyone here had a similar problem with a solution? I'm ready to start line tracing the individual components but need to know EXACTLY which components or sensors that quad controls so as to troubleshoot the sensors and harness wiring on that circuit.

The only thing that my car doesnt have working now (that I know of) is my A.C. which went out a few years ago.(compressor does not come on at all) but this sensor was disconnected after it went out and no code was being reported with the sensor line disconnected.

Any takers?

Thanks in advance.

Steffon

a vaccum hose leak. or not connected.