I just got my 90 out of the shop and now the infl rest light is on.It wasn't on when it went into the shop.I had injectors and ecm replaced.Mechanic swears it was on ....oh well.Can I turn this light out using the ALDL terminal?A grounding issue with this light was fixed 2 years ago.Did replacing the ecm have anything to do with this ?I'm starting to like this car more and more.

Thanks Wayne K

 

I have a 1990 with the same problem. Airbag light along with set belt warning light. I bought my car that way. Chevy dealer tried to fix problem but, Only managed to turn the light off for a few days by reseting somthing. They say they can't find the sensor needed to make repair since it's only used in 1990 model and has been out of production. Only used parts can be found and all of them bad. If you get it fixed Let us know how... I've learned to live with the light, Its the only thing wrong with the car.

 

You guys are experiencing one of the most common issues with the 90. I had the light come on several years ago due to the right sensor and just a few months ago the light came on again this time because of the left sensor.

The problem is corrosion between the frame and the sensor. Mine was very easy to fix. I just disconnected the battery, removed the two bolts holding the sensor, sanded both the sensor/frame faying surfaces, coated them with dielectric grease and reinstalled the sensor.

To turn off the light I use a special plug/switch I bought from Corvette Central (I think) for a nominal cost but there are other ways to do it.

Just make sure you disconnect the battery before you mess around with the sensors. Good luck.

90Indy

 

Yep most of the time it's the right front frame sensor that goes bad. Sometimes you can repair the problem by DISCONNECTING THE BATTERY then removing the sensor and taking a dremel tool or small grinder and removing the paint or corrosion on the frame where the sensor sits and sanding the bottom of the sensor and applying some dielectric grease to both areas then I put small star washers on the bolts (better ground) and re fastened em. Then ya gotta clear the code to turn the light off. Mid America sells the connector/button tool that hooks to your ALDL connector under the dash that will remove the code Remember sometimes cleaning the frame and sensor won't always work and the sensor must be replaced. Pipe

 

Just a fwiw on the InflRest + seat belt light. Most of the time it's not a part failure, but rather a loss of ground issue. The sensors are bolted to the frame rail and they use the bolts/mounting tabs as a ground. The fix is to remove the sensors and clean up the tab and frame area and apply some di-electric grease and use star washers on the remount.

Now to get rid of the code is the tough part. I tried several times and until I made a "tool" to do the grounding and un-grounding of the proper ALDL pins I had no luck. I found that the timming of the grounding & ungrounding was key.....my 90's FSM says 3 seconds on the grounding & ungrounding, +/- .5 sec. I bought a momentary switch and used phone wire as my leads because it fits into the ALDL sockets. Then I used my watch to do the timming. I was jazzed when my light went out.

Check the mounting points for crud and then try the switch thing. Ofcourse, if you have a TECH1A, clearing the DTC from memory is a snap.


Tom

 

This is a good write up on servicing the inflatRest light.

https://www.corvetteforum.com/techti...D=46&TopicID=2

 

I just fixed mine. The tech explanation on the forum is not very detailed. First you should find out what the codes are. I used Gordon Killebrews grounding plugs which work great. If you find out which code, it will probaly be a bad ground. There is GM bulletin describing the problem and fix. You must with the battery disconnected remove the sensors (little black boxes with a bolt front and back) from the front frame rails. Sand both the sensor and the frame rail clean and apply di-eletric grease to the bottom of the sensor and reinstall. I would suggest you do both sensors at the same time. This basically only applys to the 90 cars since GM put dieletric grease on the 91s and up. Getting to the sensors requires a little bit of work. On the drivers side you need to remove the fender, battery, inner wheel well cover and battery tray. On the passenger side remove the fender, inner wheel well cover and windshield washer fluid bottle. The passenger side is the harder one to get to. After you reassemble everything, hook up the battery and reset the codes. To do this I used the grounding plug for the airbag and plugged it in to the ALDL with the car off. Then I turned the car on(not starting), waited for the airbag light to start blinking.As soon as it does remove the plug and count 1001,1002,1003 and plug back in and then unplug and count 1001,1002,1003 and plug in.I did this about 3 or 4 times. Then turn off ignition, unplug ground plug and start car. The airbag light should come on for a few seconds and then go out. If not then try the reset procedure again. The tech procedure on the forum tells you how to reset with a wire which will do the same thing. Or you can use the switch one from Mid America or where ever and reset it with that. I personally like Gordons ground plugs cause they are simple and you can use them whenever you have any other fault lights come on. Hope this helps. It took myself and a friend about two hours to do this, with less info than what I'm writing here.

 

When I grounded the pins in the ALDL Connector I had a trouble code #26 which is the right front frame sensor fault so no matter how much I would have cleaned the corrosion and sensor it would still have the INFL REST light on no matter what I did. The sensors have Ohm specs and the connector is down in the footwell area of the driver & passenger compartment. Pipe

 

Yeah, I just did mine as well, It was a P.I.T.A. to get at the right sensor however it is doable. The problem becomes obvious cause the only ground is the mounting bolts. Getting rid of the codes is tricky doing the 3 second counting thingy. But I did follow the F.S.M. and I did succeed. Just sand the frame and sensor, put on the grease and feel good about fixing it yourself. Remember, the tech at the stealership has probably never done this repair as well. Think about paying them $90 bucks or so an hour to learn how to fix your Vette. By the way it is a good thing to learn how to read the codes by grounding the correct pin to the seat frame. As a old Mack Truck retiree it gives me great pleasure to fix a problem myself and keep the money in my pocket, Happy Corvette motoring. Allentown Ernie.

 

According to Gordon Killebrew, "If fault codes 15,16,25 or 26 are set, refer to GM bulletin 90-436-9J. There may be corrosion between the right or left uniframe impact sensors and the uniframe." So if you clean the sensors and the frame like I suggest and reset the light you should have no more problems. Of course there is a possibilty it could be a bad sensor, but more than likely it will be a bad ground(the sensor to the frame). If all else fails Gordon is only a phone call away.........

 

Peel back the carpet in the footwell area an OHM them then you'll know for sure. Pipe

 

I wouldn't put an ohm meter on those sensors unless you want your airbag to go off. The easy fix is to clean the sensors, put the di-electric grease to them and reset the light. Trust me this is the most common problem with the 1990 airbag system

 

If the battery is disconnected it wont happen cause your not testing the connector that goes to the DERM your testing the pigtail to the frame sensor Pipe

 

Goodluck

 

You are absolutely right .The timing sequence is important."K" terminal to "A" and follow the instructions .It helps if you run 2 wires from the aldl terminal long enough that you can sit in cars seat with watch on dash,makes the timing seq. MUCH EASIER.Car fixed.

Thanks Wayne K

 

Glad to be of some help.

After many years on this forum (almost the beginning) I have seen what seems to be just about every problem imaginable posted again and again and usually a solution. Unfortunately, the answers
often have been buried in the archives and the archives seem to have been lost through program "updates" etc. This one was still there!

Since I noticed the trend for the archives to go "missing", I have made copies of the "good stuff" and keep them in a loose leaf binder for future reference. They have come in handy!

Good luck with your 1990. (I have had mine for 17 years).

 

Where is this sensor physically located in the car??? I have this problem as well on my '90

 

I have this light on, been on forever, I hate it and I hate the service ride control light, I know what needs to be done. Always an adventure/pita fixing stuff on this car... But man does it make a guy happy to do it himself and save cash. Found this image via google images on the forums here. What a great tool google images.

 

Yes, this is the way I did it. I ran one wire to ground and another wire to the proper terminal on the plug. I sat in the drivers seat and touched the wires together at the proper time. I followed the factory manual instructions and the wife called out the seconds to me. The sensor is on the right frame rail and a little tough to get at but doable. Sand sensor put on dialectic grease and the damn lite goes out after doing the reprograming thing. Mine has worked properly for years after this fix.

 

When all else fails, pull the bulb. I understand that the air bag is still functional when the light is on so it matters little if the bulb is in the socket or not. Sure beats black tape.