Help! 1992 C4 ASR issue

[daddydug]

I have a 1992 corvette base coupe and a couple of days ago while I was driving it The check engine light came on, the service ASR light came on, The speedo quit working, the AC went hot, and the security light on the left of the instrument cluster began to blink. I turned the car off and then back on and problem was gone. It has happened a couple of times since then. It seems that after it sits for a while it resets. Any ideas? Anyone else had this same set of circumstances and know what I should do to fix the issue? Thanks for any help guys. It is my first corvette at 42 year old and I love it. I sure hope there is a simple fix.

 

[93Rubie]

First thing you are going to want to do is pull any codes from the ECM, ASR, etc...systems. I would start there. Do a search here to find out how to pull the codes. You can access them via the CCM and thru the instrument cluster. It is detailed how to do this in the Field Service Manual. You might find it on here if you do a search.

 

[tmkassin]

Clean all your grounds and the positive wires connected under the battery. Hope that helps.

 

[daddydug]

Thank you

Thanks for the info guys. I am going to clean all pos and grounds under battery and try to pull codes through the ccm. Will let you know what I get. Thanks a bunch. Ok. So I got the codes. Easy to do BTW. Grounded top right and bottom left where you plug in the diagnostic tool with a paper clip(A and G). Got a bunch of codes H41= RF valve solenoid fault, H27=LF wheel speed sensor continuity fault, H28=speed sensor frequency error, H69=couldnt find what this code means, and H72=serial data link fault. What should I do next guys. Thanks again for all the help. I really appreciate it.

 

[John Robinson]

The grounds are the life blood of these cars. The way they are wired is to have several sensors go to a common ground bundle and then to the ECM The ECM then monitors those ground bundles for the ground voltage and from that it adjust the fuel trim etc. So if you have a weak ground then the ECM perceives a problem with the circuit but can only name the sensor for that circuit. For that reason do not assume a part is bad just because it shows up as a code. Again the ECM can not diagnose the wires so it can only point in the direction you should look.
As you can see there are pleanty of grounds to check.

 

[ACROCK]

Asr problem help

Same problems ck eng flashes asr comes on air stops mph stops sys light flashes

checked all connections to ecm etc all clean 1993 with 56000 miles grounds look clean

 

[John Robinson]

Low milage has nothing to do with the grounds being good or not. Nineteen years of moisture and corrosion between the ground and the frame is the problem. I used a die grinder with a small wire brush in it to clean the wire connector and the frame so that they would make good contact. Also the ground wire on the front of the block for the coil/tachometer needs to be done. While you are there remove the coil and use brake cleaner to clean all the dirt and grease from behind the coil were it goes against the block. Don't forget to liberally cover the back of the coil with heat sink grease (I use Dielectric Grease) before reinstalling it. That is spelled out to be done in the Field Service Manual (FSM)


Welcome to the CAC

 

[Schrade]

Are your spark plug wires routed properly? IN the sp wire plastic looms?

Wires laying on metal surfaces causes grounding out, AND, EMI - electro-magnetic interference, same as a nuke. Causes problems with ALL solid state electronics, false codes, etc., ... (straight out of FSM).