INF REST issue

[tomtom72]

Hi guys,

air bag issue and it's not the corrosion under the sensors on my 90....I checked the drivers side, code 16, and it is still clean from when I did both of them when I got the car.

Looks like the diagnostic chart for 16 says it's either the ground or the wiring or the DERM. Also seems to be some special equipment to run the flow chart properly. Seems without tool # J---- I'm taking a guess unless I find fried wiring or something unplugged.

Need any advice as the only part of the dash I've been behind is the center stack to do the Dr Don thing w/the head unit. The wiring for the SIR sys looks to be burried fairly well and the DERM itself looks like it's half way to doing a heater core job.....oh joy!....looks like if I do this SIR thing I might as well do the "while we're this far" thing on the H/C...just for sh&t$ and giggles.:o I know, wrong side of the car for the H/C but the FSM makes it look like the center stack and the driver's side dash has to be out to get to the DERM..... might as well take apart the other side & do the H/C at the same time?

I guess I need some one to tell me not to pull the bulbs from the I/P cluster(little guy w/the seat belt) and the DIC but to fix the SIR properly. Oh, yes, the DERM's are ava @ about 500+ a copy. I'm not cheap but this stuff keeps eating at my mod buget!:mad:

Any opinions?
:cheers:
Tom

[We Gone]

Tom,
Don’t give up yet… I went thru about the same issues with the 90 I had. Find the connectors under the dash and check them. As you probably know they are yellow wires, one of them on mine had some corrosion in the plug. After I got it fixed it still took me several attempts to get the code cleared over many days.. Like 20+ tries each time

[tomtom72]

Ah, the voice of reason from the PSP!

:hello: Hi ya Steve! Okay.....I'm gonna take the bolster down and hunt up the wiring and pray that it's something like what you encountered. Yea, I'm easy....but not cheap!:mrgreen:

Thanks for listening bud!:thumbsup: but it's gonna have to wait till next week sometime because I have a Fall Folliage run to attend tomorrow.:wink:

:cheers:
Tom

[TNorthcott]

I just developed the same problem on my 90. The INFL REST light came on and my seat belt light on my dash stays on when my seat belt is engaged. I haven't messed with it yet, but if it is a simple plug check I am in. Can you tell me where exactly the yellow wires are? The driver or passenger side and if I need to remove anything to get to them?

Thanks for the input, I had some real issues with this baby initially and got some great advice and parts from this site, especially from Jeff.:-D

[tomtom72]

TN,

Over at the netregistry site in the maintenance section under the "how too" and "common issues" tabs is all the simple fixes. The factory put out a TSB on the grounding issue with the sensors at the front of the frame, left side under the brake M/C on that rail and the right side just inboard of the washer reservior on that rail.

Briefly, the sensors loose the ground to the frame due to corrosion & dirt. Ya got to r & r them and clean up the mounting points and that does the grounding issue and usually allowes the DTD to be cleared & you're dunn.

Driver's side = r & r gil panel, batt & tray and the sensor is forward & inboard from the batt tray, on the frame.
Pass side = r & r rear wheel house panel after r & r'ing middle w/h panel and the sensor can just be seen aft of the rear w/h panel on the rail. That one is a bit blind but doable without any further disassembly.

I haven't started looking for the connectors yet. Driver's side ya take down the knee bolster and it's down by the base of the steering collum, thick yellow wire.

Post up if ya need more specifics....I'll share what I've dunn so far.:thumbsup:

:cheers:
Tom
Oh, yea, welcome to the asylum!:hello: :mrgreen:

[John Boothby]

I had the same problem. Inf Rest light was on as well as seat belt light. I believe I had code's `14; 16 and 24. I removed front sensors and cleaned them. Replaced them using electric grease. Light stayed out for a little while, then came back on when car was warm. Code 24 was showing. I replace the right front sensor and lights are now out and have remained out. Part from Tom Henry Chev was around $126.

[John Boothby]

By the way, DISCONNECT THE BATTERY before tinkering with these. You do not want an unscheduled deployment of the airbag!!

The passenger side connector is under the carpet below the glovebox. Just pull the carpet back and you will see it.

[tomtom72]

Thanks John for the head's up on the location of the pass side connector!:thumbsup:

If I'm gonna check the driver's side connector....I'm gonna do the pass side also.

:cheers:
Tom

[John Boothby]

To be clear on the location of the right connector, it is under the FLOOR carpet against the firewall under the glovebox. Just pull it down and you will see a gray connector.

[TNorthcott]

Thanks for the information, unfortunately I have to go to Taledega for a race this weekend but I hope to fix this problem on Monday. Of course then I will be asking for help with what I am sure will be yet another issue. As my dad always said, it isn't the cost of the car it's the cost to keep them on the road!

[jrd1990zr1]

Thanks John for the head's up on the location of the pass side connector!:thumbsup:

If I'm gonna check the driver's side connector....I'm gonna do the pass side also.

:cheers:
Tom

Tom,

I had a similar problem. Cleaned both sensors, cleared the codes worked for about 6 months. Then the code came back for passenger side. pulled the plug apart in the passenger foot well, cleared the code and has been working since.

Someone told me not to use dielectric grease on the bolts and connectors, it could cause an open in the circuit.

Clearing the codes is a PITA

John

[tomtom72]

Thanks John for your thoughts. I did the proceedure described over at the netreg site about correcting the frame grounding issue as soon as I got my Z.

I redid the driver's side sensor as my DIC is giving me a code 16, but there was no corrosion to interfere with the frame ground. I figured the next thing was to ohm out the sensor as per the FSM proceedure but I was caught off gaurd by the admonishments in the FSM about using a VOM. The FSM says to use this K-M tool kit for testing on the SIR system.

The warnings gave me pause to think about what I was doing. I reasoned that I can't see what could go wrong if I used my VOM to ohm out the sensor only and not any other part of the system.

Hopefully today I will have time to ohm the sensor to see if it is the cause of the code 16. I can't find any corrosion at any of the connectors' terminals and on the frame....I'm hoping I can isolate the trouble with my VOM and not set off the bag or harm any of the other parts in the system....I just can't figure what could go wrong if I ohm out just the sensor and not any other part of the system.

:cheers:
Tom

[jrd1990zr1]

Tom,

I disconnected my battery for about 1/2 hour then disconnected the yellow sensor lead from the sensor inside at the passenger footwell. Then used the procedure to test the resistance, used an ohm meter on the sensor. It checked out OK. Cleaned up the pins on the connector and put it back together, Cleared the code and (knock on wood) has worked since. The lock that holds the connector together or the connector itself might have loosened up, at least on my car.

Best Regards, John