1991 INTL REST light gone crazy

[billschroeder5842]

My INFL REST light comes on and off intermittently with no apparent reason on my 91.

There seems to be no rhyme or reason. I can start the car, watch the flashes go off drive it and it sometimes comes on. A few more miles, and it may go off or stay on-- you pick. Most of the time I don't see it and everything is normal, but every now and then It pops out of no where.

Also, the car seems to reset itself when I turn it off and/or go through a new start cycle again.

Now, I've read about the 90s having issues and the fix was made for 91. I read that due to the location of the sensors, they are prone to corrosion and the fix is to pull them off, clean the surfaces and reinstall.

I've also read that the code need to be cleared, but the light goes off. Does the system store the code or does it disappear?

Any ideas?

[jss06c6]

Bill,

Check out Mike's post. (MickeyD). Good write up there. He's dealing with the same issue on his '90..

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[MickeyD]

Boy am I. Don came up and he tried to help clear it with paper clip and then we went to his house and tried Cliffs code clearer. Didn't help. Infl rest an seat belt light still on. Thanks to Don (32valvesftw), what great help today. Did bring his ramps to help with oil change. Thanks again.

[jss06c6]

Mike,

Feel free to come over here and put it up on my lift for next oil change!

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[jss06c6]

Mike,

Let's see if we can clear it up. How's your schedule next week?

We can put it in my shop and get after it.

Steve

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[WVZR-1]

OP - Diagnostics, codes and procedures for a '91 are way different than anything you see mentioned for a '90 MY. Disregard everything and do diagnostics in the FSM. A FLASH diagnostics will only do current codes I believe BUT if there are HISTORY codes it will I believe flash a 13 and then the HISTORY needs read using a scanner.

Doing the sensor maintenance is time wasted without doing the diagnostics first for '91 or later (MY THOUGHTS). Since your SIR is intermittent it "hints" that when there is NO SIR there's only a stored history likely. If checked when "LIGHT ON" you could likely assume that if one FLASHED is likely the same in the history. A read of the FSM 9J before doing a thing. A poor connection maybe at the connectors at the column base, the air bag itself, the DERM or to the sensors. A '91 also has an ARMING sensor.

[billschroeder5842]

OP - Diagnostics, codes and procedures for a '91 are way different than anything you see mentioned for a '90 MY. .....A poor connection maybe at the connectors at the column base, the air bag itself, the DERM or to the sensors. A '91 also has an ARMING sensor.

I drove her yesterday with about 5 on/off sequences-- nothing-- all ops normal.

One thought I had is that I've been doing a lot of cleaning under the hood and engine (Oil line replace) as of late. Simple green, hose rinsing, brake cleaner..etc. The under hood is looking better, but some of the water may have worked its way to a sensor causing a short?

I'm thinking of taking the panels off and getting after the sensors (cleaning and re-grounding) as a preventative maintenance, but other items keep taking precedence as long as the light is out!

BTW... is there a "preferred" code reader/clear or is the paper clip method the way to go? I had an 82 with the ALDL and I bought a connector to my laptop. Very cool program.

[32valvesftw]

Mike, the more I think about your situation, its the sensor on the passenger side. What we were seeing when the light momentarily went out was the system recognizing that the process was done, and the resetting due to the fault. The next step should be cleaning the connections and checking the wiring, then see if there is a code. I'm happy to help f you need.

[jss06c6]

I drove her yesterday with about 5 on/off sequences-- nothing-- all ops normal.

One thought I had is that I've been doing a lot of cleaning under the hood and engine (Oil line replace) as of late. Simple green, hose rinsing, brake cleaner..etc. The under hood is looking better, but some of the water may have worked its way to a sensor causing a short?

I'm thinking of taking the panels off and getting after the sensors (cleaning and re-grounding) as a preventative maintenance, but other items keep taking precedence as long as the light is out!

BTW... is there a "preferred" code reader/clear or is the paper clip method the way to go? I had an 82 with the ALDL and I bought a connector to my laptop. Very cool program.
Bill,

Check the ALDL connector you have for the '84, I suspect it is early style. You can pick up a cheap OBD1 code scanner at most auto parts stores. It will give you the codes, but not clear the codes.

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[WVZR-1]

I'm thinking of taking the panels off and getting after the sensors (cleaning and re-grounding) as a preventative maintenance, but other items keep taking precedence as long as the light is out!



This I believe would be "time wasted" without doing diagnostics 1st.

Scanning and diagnostic requirements are very different dependent upon the system that you want to check. The "jumper" FLASH or the ECM/CCM through the DIC are very reliable for some. Short of a quality Tech1/1a or the Snap-on offering everything else is insufficient. A laptop for "run diagnostics" yes but NOT for "controlled devices" in the car.

[MickeyD]

Mike, the more I think about your situation, its the sensor on the passenger side. What we were seeing when the light momentarily went out was the system recognizing that the process was done, and the resetting due to the fault. The next step should be cleaning the connections and checking the wiring, then see if there is a code. I'm happy to help f you need.

I think so too. The only thing that weird to me is the code 12, when we try to clear. But also the drivers side has been done. Unless I screwed it up changing the battery this year.

I'm up for anything. Your place, my place, Steve's place. I'm open Mon and Tues. Out of town Wed-Fri afternoon. Open next weekend.

Btw Bill, didn't mean to hijack your thread! Once I learn how to do this, I'll come up and help you or you can come down. Guess I'm gonna be forced to learn how to mechanic if I'm gonna keep these cars.

[MickeyD]

I deleted my post as I have totally different experience regarding clearing Codes.....I have NO Codes on five ZR-1s including a 91' and 95'. Also use my ALDL Code Reader on all of them including the 95' and a standard Corvette (L98). Good Luck Guys :cheers:

Dynomite thanks for all your help. Your posts helped Don and I a lot yesterday, even though we didn't get it fixed, it was a great reference.

[32valvesftw]

Same here Cliff. No reasons to delete your post. I think your advise was spot on. A code cannot be cleared unless the underlying issue is addressed, in this case the underlying issue still exists.

[WVZR-1]

I deleted my post as I have totally different experience regarding clearing Codes.....I have NO Codes on five ZR-1s including a 91' and 95'. Also use my ALDL Code Reader on all of them including the 95' and a standard Corvette (L98). Good Luck Guys :cheers:

Well I didn't say a thing about what you call a "CODE READER" - I mentioned to the OP who has a '91 that he needed to read 9J in the FSM and do "FLASH" diagnostics FIRST. Your "CODE READER" is nothing more than a "FLASH" READ DEVICE. I don't believe there's any similarity of the codes '90 to '91 and later.

Your links etc all seem to be directed towards '90 SIR which didn't address "squat" for the OP. AGAIN - "MY THOUGHTS"!!

I mentioned CURRENT and HISTORY retrieval for a '91 and what's required for clearing HISTORY - I don't believe your "CODE READER" can accomplish what's required on '91+ removing HISTORY. If you attempted to READ a '91+ that had been repaired after displaying CURRENT CODES it would likely ALWAYS display a CODE 13 which I believe means there's HISTORY in there.

Anyone with any year needs to familiarize themselves with 9J if they've SIR issues - anyone and any year!

[billschroeder5842]

Btw Bill, didn't mean to hijack your thread! Once I learn how to do this, I'll come up and help you or you can come down. Guess I'm gonna be forced to learn how to mechanic if I'm gonna keep these cars.

Mike- no hijack made- I really like to learn about the nuances of our cars.Who'd have thought that the 90 and 91 had those differences.

BTW... I did the "Flash" read on my car today. Nothing but "12s".

Poltergeist. I'm convinced of it.

[MickeyD]

Mike- no hijack made- I really like to learn about the nuances of our cars.Who'd have thought that the 90 and 91 had those differences.

BTW... I did the "Flash" read on my car today. Nothing but "12s".

Poltergeist. I'm convinced of it.

Poltergeist, no. I'm convinced it's a virus. When Dave moved his car from between ours in Buffalo your car gave it to mine.

[billschroeder5842]

Well, guilt, paranoia and flashing 12s over came me (coupled with a free day) so I tackled the passenger side SIR module.

While everything was apart, it also gave me an excuse to do some wiping, cleaning, vacuuming (the previous owner must have parked under a pine tree), zip tieing wires, rerouting, painting brackets, scrubbing wheel wells and the finally body panel alignment.

When I finally got to the SIR module, the contacts seem to be "ok" but just barely- there was enough of that white corrosion stuff to notice. I also saw that the mounting was on the frame, just "down hill" enough that it would have been in the flow of water and other chemicals that I would have used when cleaning the engine. As someone mentioned, the water may have caused a short.

I wire brushed the frame mounts, both sides of the module and bolts. I put di-electric grease on the frame and both sides of the module mounts. The PITA of the reassembly was the 10mm bolt on the SIR module as there is limited room and my hand are too big.

I re attached the battery cable, started the car and had zero INFL REST flashes as there was before, so I'm guessing that I "got it."

Thanks everyone for giving me the direction to "get after it!"

[Dynomite]

I just did the Drivers Side on my 1991 today.....much easier than the Passenger side ;)

I also did a couple other ground wires when I was there including my Starter Relay Ground Wire.
Followed up by painting the area and ground connections with Black Rustoleum.

http://i287.photobucket.com/albums/ll142/dynomite007/Dynomite20/1ca6af37-9139-4c49-87ee-1bcdb2afcba0.jpghttp://i287.photobucket.com/albums/ll142/dynomite007/Dynomite20/cf28500a-7065-489c-849e-22b002bf3412.jpg

[billschroeder5842]

Dynomite--Driver side is next for me!

So how much easier is the drivers side than the passenger? I'm numb at the moment from the afternoons project or maybe its the second glass of wine. I'm not sure which?

[Dynomite]

Dynomite--Driver side is next for me!

So how much easier is the drivers side than the passenger? I'm numb at the moment from the afternoons project or maybe its the second glass of wine. I'm not sure which?

Very easy.......especially if you have a 1/4 socket wrench with 3 inch extension and a 13mm and 10mm 1/4 drive socket. You just have to remove battery and battery platform (4 - 10mm bolts/screws). You can see in the photo you have plenty room. On the battery platform one lower 10mm screw is a bit tight but you can get at it with a 10mm flex head ratchet or just a plain 10mm open end box wrench.

The Side Panel with 3 #30 Torx and two 10 mm bolts (the lower 10mm bolt you just loosen a bit in the gap) is easy to remove as well.

[Dynomite]

Very easy.......especially if you have a 1/4 socket wrench with 3 inch extension and a 13mm and 10mm 1/4 drive socket. You just have to remove battery and battery platform (4 - 10mm bolts/screws). You can see in the photo you have plenty room. On the battery platform one lower 10mm screw is a bit tight but you can get at it with a 10mm flex head ratchet or just a plain 10mm open end box wrench.

The Side Panel with 3 #30 Torx and two 10 mm bolts (the lower 10mm bolt you just loosen a bit in the gap) is easy to remove as well.

You will get a kick out of this.........and a BIG thanks to Marc Haibeck for answering my questions :thumbsup::thumbsup:

This from Marc.......(edited a bit) :handshak:
For the 1991 through 1993 the Air Bag Sensors do not have to be grounded to work in a crash....they DO need to be attached to the Frame Rails however. The Grounding requirement (Code 16 and Code 26) of the Air Bag Sensors on the 1990 was set up to assure the sensors were attached to the Frame Rails. If the bolts were removed from the sensors the sensor would pass as air bag deployable but would not actually deploy the air bag for obvious reasons. This explains why I got NO INFL REST warning on the panel when I totally removed the 1991 Sensor from the Frame Rail in my test.

I am now thinking the Air Bag Sensors on the 1990 ZR-1 will function and Deploy the Air Bag even if not grounded. The 1990 Air Bag Sensors will only appear not grounded/not connected on the panel as INFL REST indicating/suggesting the Air Bag Sensors are not installed when in fact they ARE Installed. To get rid of that INFL REST Indication on the Panel (as well as the Red Seat Belt Indication) requires the Air Bag Sensors be Re-Grounded. I am not going to jar the Air Bag Sensor to see if the Air Bags Deploy to test that theory.

If any of the listed faults 21 - 26 for the 1991-1993 were detected in a self test the INFL REST will appear on the 1991-1993 panel. These faults are listed for the 1991-1993 in the ALDL Fault Code Sticky above this technical section.

21 Steering Column Resistance Too High
22 Steering Column Resistance Too Low]
23 Steering Column Circuit Voltage Too High
24 Steering Column Circuit Voltage Too Low
25 Short to Battery in Steering Column
26 Open in Steering Column

Now for the 1994-1995 since two air bags are used has different codes and there is NO SIR diagnostic terminal as indicated.
The 1994-1995 design requires a TECH 1 diagnostics because the data is sensitive as a result of Government Regulations. On the 1994-1995 ALDL Code Reader when used with Adapter I have noted SIR (the RED BUTTON) is NOT used See Item #3 ALDL Fault Code Reader/Eraser (http://forums.corvetteforum.com/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-3.html#post1581564097). All other Codes are readable using the 94'-95' Adapter with the ALDL Code Reader.

Marc Haibeck ALDL Connector Functional Description (http://www.zr1specialist.com/HAT%20Web/Tech%20Info/aldl.htm)

[MickeyD]

Dynomite--Driver side is next for me!

So how much easier is the drivers side than the passenger? I'm numb at the moment from the afternoons project or maybe its the second glass of wine. I'm not sure which?

Congrats Bill, glad to see you got it fixed. Why don't you make a run down here and fix mine! Lol. Thanks for coming back Dynomite!

[billschroeder5842]

Very easy.......

Thanks for the direction. I tackled the drivers side this afternoon (there is no l could leave one side "not done") as there is no way I could not be symmetrical.

Straight forward with nothing goofy. I did take your advice and clean up connections and grounds while I was in there messing around.

I probably could have done it in 90 minutes but it took longer with all the cleaning, wiping, vacuuming, wire brushing, taping.... etc.

One less thing to worry about!

[Dynomite]

Thanks for the direction. I tackled the drivers side this afternoon (there is no l could leave one side "not done" as there is no way I could not be symmetrical.

Straight forward with nothing goofy. I did take your advice and clean up connections and grounds while I was in there messing around.

I probably could have done it in 90 minutes but it took longer with all the cleaning, wiping, vacuuming, wire brushing, taping etc.

Excellent........and yes on that junction block.....me also ;)

and yes on being symmetrical .......me also.....had to take a wheel back to Discount Tire the other day to get remounted......turns out I had two left Sawblade Rims for new Nitto 555s. Just bugged me one side did not look like a saw blade :D

[ssrszz4]

Does the infl

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[ssrszz4]

Does the Info rest light being on affect secondary throttle operation?

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[billschroeder5842]

Does the Info rest light being on affect secondary throttle operation?


No, nothing related.