Hey guys! Well i have tried the search feature and i still cant find the answers im looking for so im turning to yall. About 3 months ago i purchased a 90 vette with 103k and the motor was replaced 2k before i got it... she runs great. On the driver info center the air bag light stays on as well as the seatbelt light on the cluster. What would cause this as well as where do i start with diagnosis? Also i have a very slight miss at idle. What are the areas I need to watch for? any help is greatly appreciated!!

Thanks
David

 

ummm please

 

Superdave, I have a 1990 coupe also. I purchased a corvette service manual along with the electrical supplement manual off of ebay for 60 bucks. It is the best $60 you will ever spend. You can pretty much fix almost anything with it. I would send you some info on how to troubleshoot that however looking in the manual it has 48 pages limited just to that problem. I told you it was thorough!. My lights on mine are on the same as yours, I just haven't gotten around to fixing it yet. Basically, it has tripped the error code in the DERM which maintains a record and it will be that way until it is cleared. Of course if the problem still exists it will come right back. There are 18 error codes and they can be read using the following procedure. Turn the ignition to off. Ground ALDL terminal "K". Turn the ignition on. The flashes of the INFL REST indicator lamp correspond to the digits of the two digit malfunction codes. Code 12 will be displayed three times followed by any other codes which may be stored. This will also flash 3 times and when all the codes have cycled through it will repeat indefinitely. To clear the codes, turn ignition off, ground ALDL terminal K. Turn ignition on. When the codes begin flashing, unground ALDL terminal K for 3 seconds. After ungrounding for 3 seconds ground it again for 3 seconds. Unground terminal K and wait 10 seconds. Before truning the ignition off, verify that only code 12 is flashing. If not they have not cleared properly. As you can see, there is a very detailed way to troubleshoot this including several flow charts. I think you could fix it with this manual. If you send me your email address to alzado77@***.net, maybe I can get my scanner up and running and scan them to you. I know this probably wasn't much help but there is hope, Al

P.S. Whatever you do, don't use electrical test equipment such as a voltmeter etc, you could cause the airbag to inflate! :flag

 

Hey guys my 90 had the same problem a few years back. Before I did anything I disconnected the battery. Some guys just remove the frame sensors and clean the bottom of them and the frame where they mount. They are located on the frame rails close to the firewall. You will have to remove the side panels behind both front wheels to get to them. Most of the time just cleaning them won't work. If you peel back the carpet on both sides down by your feet you will see the connector coming through the firewall it is covered in a yellow covering , the connector comes apart right there. It is a 3 prong round connector pull it apart. With the small notch in the connector down at the bottom PIN 1 is at the top PIN 2 lower left PIN 3 lower right. Use your ohm meter and jump pins 1&2 they should ohm at 10,000 or a little above 1&3 about the same 2&3 less than 1 If any of those are off then the frame sensor is bad and must be replaced they are $60 some bucks at a chev dealer. If both test out ok then it is the main DERM unit which is behind the radio and the side panels of the console must be taken off to access it. The wires leading to it will also be covered in yellow pain in the a to get to. Take a paper clip and jump the top 2 pins on the right hand side of the ALDL link which is under the drivers side dash where your right shin would be and see what codes it blinks out. LET ME KNOW HOW YA MAKE OUT OR IF YA HAVE ANY QUESTIONS I DID THIS REPAIR FOR 6 GUYS ALLREADY PIPE

 

thanks for the advice.. at least i know where to start! :cheers:

 

How did ya make out SuperDave? What codes did it blink out?

 

If anyone else has this problem, let me know. I scanned the first 10 pages of troubleshooting and emailed them to superdave. Now that I have them scanned, if anyone else wants them let me know and I'll email them to you. Give you a good place to start anyways. That and the advice Pipe gave I can't see anyone not being able to fix this problem Al alzado77@***.net :flag

 

sorry i was just able to get back here. I havent been able to do it as of yet. I have been studying the schematics before i even attempt this plus my heater core has ruptured and i must focus on that at the moment. Hopefully tommorow i WILL be trying to tackle the air bag problem and will post all results. I really appreciate all your help.

 

Last year, I cleaned the left sensor. Code went away without me having to clear it by grounding K. Infl. Rest light came back on again last March. So, I cleaned the right one. A couple weeks later, the warning lights came back. Last weekend, I cleaned both again. Tried for an hour last night to clear 26 from the DERM. No luck. My next step is to check the 3-prong connection as you suggest with a ohm meter. I think I know which one you're talking about. By removing the panel under the dash where the ALDL connector is, I should find it. Have you replaced a sensor? If so, how hard is that? :smash:

 

lakerat code #26 is the right front frame sensor. To get to it you must remove the louvered side panel right behind your wheel. It is located on the frame rail about 7 inches from the firewall and the connector goes through the firewall and connects down by your feet in the passenger compartment. DON'T FORGET TO UNHOOK YOUR BATTERY!!!!!!!!!!

 

well i pulled the codes from the computer and got 16, 26, 35, 41. thought that was a lot of codes for that system so i cleared them all out. The light has been out and has stayed out for the last couple of days and there are presently no error codes. so im thinking that it might have had a momentary fault in the sensors and they just have never been cleared. am i thinking right? thanks for all the help!

 

Dave code16 says left front frame sensor #26 is the right hand frame sensor #35 is inflator squib current open circuit and#41 is indicator lamp circuit shorted to battery or ground. Thats good that you got the codes cleared and the lights are out now hope they stay out PIPE

 

My 1990 from brand new has had this problem on and off for 14 years. I have had the dealership replace the sensor 3 times, at my cost and clear the codes only to have them come back a year or two later. The corvette specialty shop called Tony's Corvette in Gaithersburg, Md. Removed the sensor and gound down the frame rail alot, then applied alot of dieletric grease between the sensor and the rail. It has not come back in a year so far, and am crossing fingers.

 

Corvette1990 that was my first try at fixing it. I cleaned the frame rails with a dremel tool where the sensor mounted cleaned the bottom of the sensor applied a coating of dielectric grease and even put toothed washers on the bolts when I remounted them but the INFL REST light stayed on. Thats when I checked the sensors and found out the one was bad, replaced it cleared the code and never had a problem since. ONLY HAPPENS TO 90 VETTES :rolleyes:

 

There is a good tech-tip writeup on this problem on the forum.
https://www.corvetteforum.com/techti...D=46&TopicID=2

All 90's have this problem. Good luck

 

Yeah I hate that damn air bag light mine has been great since I have onwed my 90 ZR1 now a couple of months ago I got the dreaded light I pulled the code and its a 42 which if I remember is an open circuit to the indicator light.

so I need to remove my DIC and check the light backing but im not sure of the point of this light being on with this discrepancy? because the light is obviously getting power and a ground because it is lit?

oh well I just havent had any time to do it I will tomorrow

johnny

 

Phrogs #42 is Indicator lamp circut, open circut GOOD LUCK PIPE