This has been driving me nuts since November. I just recently installed the bulb for the MIL light so I can be sure to remember to correct this problem. I have the Alldata procedure for diagnosing this problem but I wanted to just post online first and ask if this is a common problem at all among 89,C4's; and of course if there is a common solution. I only ask because I absolutely hate tracing down wires, and will avoid it at all costs! Unfortunately, I know the reality of the situation is that I will have to start tracing, but I figured i would ask.

DG

Where are all the resident gurus??????

out getting their ass kicked at team trivia.

With any code related to the MAF, I do suggest a quick wiring inspection.

If that relay is OEM, I would replace it... they don't last forever, sadly. And they are not that expensive. Don't be shocked if you need to replace the MAF soon, too.

Hey Dan, well I started to try to help on this problem. I also have a 89, and I have been screwing with this same code #36 for awhile. I thought it was fixed until today after driving the car some. Thought wrong! I have replaced relays, checked wiring, did all the FSM says and this code still keeps coming back. I must be over looking something. Sorry I couldn't help, I'll keep looking and if I do find the problem I'll let you know.

Joel

silly question, Joel, have you replaced the MAF?

I mean, they do fail.

How does the car run when the code hits?

Hey Bogus, MAF was replaced 11 years ago when I bought the car. No problems at all when code appears. Last time I looked at MAF was 2 months ago and it was perfectly clean. But I wasn't trying to hijack this thread, thanks for asking.

Joel

no, not a problem. it is continuing the discussion, so I don't even consider this close to a hi-jack.

If it helps you and the OP, then so be it!

The problem with the 1990 and earlier Vettes (hell, all cars, really) is the wiring. The SAE decided to improve the insulation in 1990, so newer cars don't have this problem. The earlier insulation is prone to chaffing, cracking, shrinking, you name it. It's bad news. Hence, checking the wiring is so important!

I agree,

I just hate having to diag wiring its a trememdous pain, and you can still miss the problem if you are not extremely careful. But I would be willing to bet you are probably correct. The wiring is so corroded on these cars there very well could be a short, or break somewhere. Only thing that worries me is that the wiring may have just corroded causing resistance, in which case good luck finding it.

DG

[IMG]http://i142.photobucket.com/albums/r97/BG528/57561871.gif[/IMG]
[IMG]http://i142.photobucket.com/albums/r97/BG528/57561872.gif[/IMG]
CIRCUIT DESCRIPTION
The Mass Air Flow (MAF) sensor measures the amount of air which passes through it. The Electronic Control Module (ECM) uses this information to determine the operating condition of the engine, to control fuel delivery. Due to contaminates in the atmosphere a residue may build up on the MAF sensor sensing wire. To maintain an accurate reading from the sensor, a "burn-off' cycle will occur when the ignition is turned off after the engine had been running a specified amount of time and engine warmed up. The burn-off function is enabled when the ECM grounds circuit 900 which energizes the MAF sensor burn-off relay. With the MAF sensor burn-off relay energized, voltage will be supplied to the MAF sensor terminal "D". Voltage will also be supplied through the normally closed set of contacts in the MAF power relay which will supply 12 volts to terminal "E" of the MAF sensor.

TEST DESCRIPTION
Numbers below refer to circled numbers on the diagnostic chart.



This test will determine if the burn-off function is operative or if the code was set due to an intermittent condition.
Check for continuous 12 volts supply to burn-off relay.
Grounding circuit 900 should energize the relay and close the contacts. If the test light is dim, check for corroded or fauly connections. If O/K replace relay.
With the burn-off relay energized there should be 12 volts supplied to the MAF sensor on terminal "D" & "E" (circuits 993 and 994).
DIAGNOSTIC AIDS
The Code 36 could have been set due to a poor connection at any of the relays or the MAF sensor. Be sure that these connections and terminals are OK. A faulty MAF sensor should not be considered as the cause if Code 36 is set

LOOKS LIKE LOTS OF FUN AHEAD!!!!!

Hey Dan, just curious did you find any problems yet with your code #36? I finally dedicated some time today to go thru the test procedure on mine. All was good, so still no closer. But before I type in a long dry paragraph on some suggestions and tips thought I would check in.

Joel

Shoot,.. no luck let...

It doesn't look very good as far as time to diagnose this week either. Tips would be great,

DG

OK, first I assume you have the FSM as per post #9. I removed the fender, and the battery for a better working area. I know someone will jump on this, but it makes all the difference in the world to be able to reach those relays without excessive bending and twisting those 20 year old wires! I just used a set of jumper cables to feed power back to the car when I needed to. Second, the burn-off relay is the inboard relay, having 4 wires. One large orange, one smaller orange, one small black,one dk blue. The only " back-probe" is in step #3, "ground burn-off relay ckt 900." This is the small black wire on the relay. I used a paper clip that I sharpened the tip with a disc sander. A good straight pin might work also. Also in step #3: probe terminal "D" of MAF sensor harness, on my MAF the terminals are lettered A thru D. So you will just have to look at the harness end as they attach to MAF for correct terminal.Mine checked out thru the entire test. But notice the last paragraph on page 6E3-A-45, refers to possible high resistance in relay. I'm going to replace both relays with AC Delco and drive it. One more thing you might want to read, page 6E3-C1-2 talks about when a code #36 is set. Good luck now that I've got you totally confused.

Joel

Joel,

Thanks for the info, I will see if I can get some time tomorrow to get out there and give it a try.

Unfortunately I STILL do not have a FSM, although I have been using Alldata and has worked pretty well for me up until now.

I already pulled the relay's (both of them) and used the battery to jump the connection and close the contacts. I heard a loud click with signifies that the relay is in fact closing, but you bring up a very good point. There might be resistance formed within the relay that is causing this whole mess... maybe on the side that the relay grounds the MAF wire. Unfortunately, I know that our cars are notorious for wires corroding and shorts occurring, so I am really keeping my fingers crossed that the resistance isn't somewhere else. Ill let you know how it works out; keep me posted on how your car is working out too!

DG

Yea I know this is a old thread, but I said I would check back with any progress on my Code 36 saga. Like I said earlier I did replace both relays with GM parts. After finally driving the car some the trouble code is BACK. So, guess I'll go thru the procedure one more time. Hope yours is fixed by now. Sorry it took so long to get back with you.

Joel

Bringing back the dead!

Does anyone know if I can just have this tuned out. Its only the burnoff wire, and on most GM vehicles the MAF doesn't even require one??

DG

Don't know exactly where you are on diags, but here's a tap test - may be a shortcut...

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HI CWB!

Well, Mr. NCKid - what's up! LeesVette said you were on the boards here somewhere...

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That damn tattle tale!

HELP!!!!!!!!
i have a 1985 corvette and i was wondering what the MAF Burnoff control module does? its the lil box hiding behind the "breadbox" i just want to know what it controls to see if contributed to all my other problems please help!!!!! help

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Frank, first off welcome to the forum. Second, I recommend starting a new thread with your specific problems, including information about your car, history, and any tests/diagnoses done.

Matthew