gregl316

iTrader: (1)

I just reciently bought an 1991 RS convertable with a 305tbi and 4 speed auto and I pulled a code. It is 32. The light doesn't come on until I have been driving at 55 mph pluss for about 5 miniuts. It goes out when the car is shut off and stays off in city driving. I thought it was a temp issue due to the fact the thing doesn't get that hot. I just put an 195 deg thermostate in it thinking that would fix it but it still doesn't get past the first line. Code 32 seems like it may be linked somehow. Is code 32 a problem and how do I fix it? I hate the service engine soon light.

EagleMark

I'd put back whatever thermastat the car calls fo first.

32. Fault in exhaust gas recirculation valve diagnostic switch

Here is a link to a GM TBI diagnostic manual on how to check each part of the EFI system and error codes.
http://www.gearhead-efi.com/gearhead...c/TBIcodes.pdf

rarebmx

iTrader: (6)

I am pretty sure that is the EGR

EagleMark

Yes it is , but the EGR valve just has a vacuum line to it from the switch which has the wires to ECM and controls the EGR valve.

Most times this is caused by leaky vacuum lines to switch or vacuum line from switch to EGR valve... or vacuum diaphragm in EGR valve leaky... or could also be a wiring issue to switch and clogged EGR valve passage way.

Read how to diagnose it in the pdf document link above...

gregl316

iTrader: (1)

Thanks I will trouble shoot it tonite if I can and keep you informed.

bitchin_buick

Subscribed... My engine light came today for the first time in three years. Under the same conditions as the OP. Thanks for the info/diagnostic link....

FYRCHKN

I pulled my hair out for over a year trying to hunt down this issue on my 91 bird. I cleaned every thing that had to do with EGR. That didn't work so I replaced everything. That didn't work either.

Here's what finally fixed it: A new gas cap.

bitchin_buick

Hijacking for an educational purpose only: Not sure about the OP, but that was the first thing I did when I left work. Took off cap and put it back on to make sure it was on good. Light came back on 20 Minutes into my drive home(highway). FYRCHKN has a good point tho, same thing happened with my ole ladies 2001 Grand Am GT shooting codes....... I will get a new cap and chase down some hoses this weekend....... Hopefully the OP will check back in and give this a shot as well before going nuts! Thanks!

Ronny

iTrader: (1)

Did you disconnect the battery for a minute or two to clear code?

EagleMark

My son works at an auto parts store and one thing they have lerned about OBDII systems is a loose gas cap will set Check Engine Light... must be a PID for pressure in tank...

But how did a gas cap fix a code 32 on this old OBDI system? Is something in EGR even remotely hooked to fuel tank? Is there even a wire/code/sensor/anything connected to fuel tank?

FYRCHKN

I have no idea. But, even after replacing everything that had to do with emissions I still kept getting the code 32. The day I put the new gas cap on I reset it again and it never came back...as long as the cap was tight. There were 2 times that I didn't tighten the cap all the way and within 10 miles it threw the code again. So, I pulled the reset fuse, tightened the cap, it didn't come back.


As a test, if you don't get the code then put your cap on loosely (without the clicks) and drive around and see if you get the code.

EagleMark

The only way that would make sense is if Charcoal Canister Purge is somehow tied into EGR 32 ERROR code?

Which may be why it is sometimes such a hard error code to cure!

EDIT: Just noticed you have an LT1, which PCM? How was it installed and wired? LT1 has a 26 error code for CCP...

FYRCHKN

I was dealing with the issue on my 91 bird that originally had an LO3 and then later was swapped for a 350 block. All my code 32 issues were with that car that I had for many years and used as a daily driver.

rusty vango

it seems to me ,after studying this issue to death.our cars can set a FALSE code 32 (egr) there are many TSBs from back in the day about these issues. GM finally released a new PROM to fix this and other false code issues.

gregl316

iTrader: (1)

I checked the vaccuume hoses and they are all fine. Then I checked the EGR valve and I think it is blown it won't draw a vaccuume. I put my pump on it and it won't draw a vaccuume. Is it bad? I ordered a new one just for the hell of it. Now will the code come in with the vaccume to the EGR plugged? Do I have to disconnect the battery and clear the codes when I fix the problem so the code won't come in again or will it come in if I don't?

EagleMark

Yup it's bad. Yes the code 32 will still come back when qualifiers are met to do the test, because MAP vacuum will not change.

Your just fixng a vacuum leak by plugging the hose.

After EGR is replaced you will have to disconect power to ECM to clear codes.

There's also another thread here somewhere that found free flowing exhaust causes the Code 32, he plugged one side, it had a crossover and no more code 32. Unplugged exhaust and it came back?

EagleMark

I had thought if you could change MAP vaules in the test would help. Above posters says there is an updated chip from GM with this done.

In another post a guy had plugged one side of his free flowing exhaust, with crossover and never got a Code 32. Unplugged the exhaust and got Code 32 back.

Another problem seems to be a Negative Pressure EGR and Positive pressure EGR. This is the complete post on reserch I did about these and other parts of EGR system. so that could be why exhaust back pressure chnged the outcome of Code 32. But I still don't understand the gas cap loose causing it?

So if the car came with a P and you went free flow exhaust it may need a N ? But if it just comes up with no changes to car it is more likely part of the EGR system has failed.

Here's the conversation:
http://www.gearhead-efi.com/Fuel-Inj...BI-EGR-code-32


Well I knew what a thermal switch was. This is what is used on carburetors vehicles to ensure EGR only operated when vehicle is warmed up. It has a vacuum source but won't let it through until set temp.
http://www.gearhead-efi.com/Fuel-Inj...1&d=1326080177

==============================================================================

But with all the GM TBI engines I have seen use this solenoid to control the EGR valve via ECM. It too has vacuum from engine but ECM controls vacuum to EGR. The extra open vauum port on this one is suposed to have a filter on it..
http://www.gearhead-efi.com/Fuel-Inj...1&d=1326080177


==============================================================================
Found this picture of Positive EGR.
http://www.gearhead-efi.com/Fuel-Inj...1&d=1326080177


==================================================================
Found this picture of Negative EGR.
http://www.gearhead-efi.com/Fuel-Inj...1&d=1326080177



So there's the difference. An extra spring and a vent.

=====================================================================
Digital EGR http://www.gearhead-efi.com/Fuel-Inj...1&d=1326080177

gregl316

iTrader: (1)

Well I replaced the EGR it had an N on it. I disconnected the battery. The next time I had it on the hwy cruising at 60 for over 5 miles it came on again. Now I am lost again. Is this code a problem, or can I just not pay any attention to it? I hate the light. It goes away once I shut the car off, and doesn't come back till I am on the hwy at 60 for 5 miles or so.

FYRCHKN

Drop $5 on a new gas cap, clear the code, and see if it goes away. I know everybody is ignoring something this simple and cheap but that's what worked for me after putting a completely new EGR system on my old TBI.

EagleMark

I've seen weirder things happen but usually find a reason... can't find a reason why a new gas cap would fix it. But I would try cause it worked for you.

Code 32 is a test of EGR system. When qualifiers are met like above 50 mph for certain time etc... ECM will close EGR valve and measure MAP kpa. MAP kpa will increase when EGR closes and if it's with in specs in chip/bin it passes. If not it fails. If EGR valve and solenoid and vacuum lines are all good and to correct locations and passage under EGR into intake being clear and not plugged. It should pass. That said a vacuum leak in line to MAP or a bad MAP could cause this as well?

Reasons why it would fail could be change in MAP when test is run does not meet guidelines in chip/bin. This could happen when an engine is worn and not producing proper vacuum/kpa or if engine has a vacuum leak and not running correct vacuum/MAP kpa.

I don't know bin hex enough but you could change boundaries of MAP reading so test passes, ot turn off test, or turn of code 32... it would be bin specific.

I don't know if it was this thread but it was mentioned Code 32 was such an issue GM put out a new bin...

The only reason I can think of that a gas cap can fix this is something to do with CCP Charcoal Canister Purge venting to tank, but still can't understand how that would change MAP reading of Code 32 test. But if it was a leaky gas cap it could also be a leaky vent to Charcoal canister or hole in gas tank etc...

gregl316

iTrader: (1)

Well I have allready replaced the gas cap. I can't find any problems with the vac lines. I think the lines are rite. The motor does have 162000 miles on it but it runs great and get 18 mpg city. So are you saying the MAP may be bad? How do you check it? Oh and what kind of vac should this motor be putting out? Wouldn't I have other problems if it was low?
Thanks EagleMark you have helped me out.
Greg

Ronny

iTrader: (1)

My MAP failed and gave no codes. Failure caused the engine to go very lean and could barely run. Intermittant as well. MAP is a 0-5V devise. I would if you ran VAC to it could be tested. I would search for the actual test procedure. It may just be a voltmeter and mighty vac that can be borrowed at AutoZone.

ps. I think it is 17-20 hg for stock. Cannot be ported vac location.

xch3no2

I also have seen MAP sensor start to fail without setting a flag, in this case the engine started to idle rough & showed inaccurate vacuum through the ALDL.

EagleMark

Yup, like they said. 19 inches of vacuum is a good reading but will vary depending on your elevation. It should also be steady, no shaking/swinging of needle at idle (stock cam motor).

I'm only saying to look at vacuum and MAP because those are the numbers code 32 looks at to pass or fail. MAP is a very good reliable piece and rarely has intermittent problems. But as said above still happens. A vacuum leak of 1/2 inch of vacuum could put you outside of pass limits.

Also just because you got new parts do not mean they are good. Ever increasing problem with cheap parts. When I worked at a Cadillac dealership in 1979 we found bad brand new AC Delco factory parts. I have found many bad new parts of all brands and quality and price since.

I posted this TBIcodes.pdf earlier, it shows factory procedure for checking all parts. Get it, save it, learn it, do it. It's easy to diagnose each circut.

RBob

iTrader: (1)

It may also be that the EGR passages are clogged with carbon...

RBob.

gregl316

iTrader: (1)

Well I am stumped. I replaced the EGR, the vaccuume hoses are all good, I even replaced the gas cap. The lite is coming on when I leave my house and on the road for about 5 min. above 55. Then I stop and shut it off when I am at the gym. I get in it and head home and now it doesn't come on. So is it almost fixed? Why when it is warming up from sitting over nite and not after sitting for only an hour or so. Any ideas will help. Thanks.
PS the idel is hi too. After sitting at a lite for about 15 seconds or so it comes down to 800 from 1000 to 1100. In the morning it is at 2000 and stays there for the time it takes me to leave arround 15 to 30 seconds is this OK?

EagleMark

Idle is supposed to be higher when cold but not that high and your high idle at traffic light is all signs of a vacuum leak, or bad IAC, or worn throttle shaft. All would lower vacuum reading and could put you outside of limits of Code 32 EGR test.

You need a scan tool or record some data with TunerPro RT with cable to laptop and post up the data log. We may be able to find something wrong.

But at this point with out data it is useless since you've covered all bases.

Then again if we knew what BCC was realesed for this fix that also could be the issue?
What BCC was this. Even then you could probably not buy it anymore, would have to burn a new chip...

EagleMark

Just for kicks, when I filled the tank on my TBI truck, not an F body. I was so curious about this gas cap Code 32 issue I left the gas cap loose and went for a highway drive... no code 32... OK not an F body test but didn't set code 32 on TBI truck...

spoazzy1

I have been having the same exact issue with my 305, its an 89 stock. I haven't started to really dig too far into it yet, but that is why I am lurking these boards too. I got the car from my little sister and she had asked a mechanic about it at one time and he told her it was just because of the exhaust that was run on it? But this is also the same guy that replaced her distributor and never reset the timing, when I first got it from her, I was riding the brakes through the school zones! It was idling at 30mph...so I do not trust what he had to say. I doubt he even hooked it up to anything seriously. We tuned the timing back down, and made sure it wasn't tweaked to overcomepnsate for anything, and once I am at the end of my street the idle is leveled out and shes running at the right RPM, but then I get her out on the road and hit about 50, and lo and behold, the light comes back on? Code 32...that is why I am glad I found this thread, gives me a place to start, finally got the taxes and am focusing the money on giving the car a good round of long needed maintenance starting with this damn code! I like you just can't ignore it, it drives me crazy!

gregl316, have you noticed any fuel smells after you are parked? I only ask because I have also noticed that I have a slight fuel vapor smell at times after I get out of it when parked, which I know can be issues with the vapor canister system, and I have read that it can cause idle issues especially at cold starts so that was where I was going to start first.

EagleMark

That is when code 32 will set. Look around other posts here I have posted the Code 32 from GM manual. Even if your EGR system is perfect it can still set a code 32.

Code 32 is a test that after qualifiers are met, like 50 on highway it measure MAP kpa and closes EGR valve and measures Map kpa. MAP kpa will change because EGR open or close is like a vacuum leak. But if it does not match kpa measurements in bin file it will fail.

Exhaust has been proven to cause this. A guy had dual exhaust put on with free flowing mufflers and a cross over pipe and got code 32. He plugged one side of exhaust and did the highway drive and no code 32. Unplugged the one side of exhaust and code 32 was back.

I think this could be fixed by changing bin file qualifiers for this test, open up the MAP kpa parameters a little to meet code 32 test! Like say they are difference of 5 kpa change to 10 kpa.

In the $EE xdf there is actually a scaler for this!

Ronny

iTrader: (1)

Good info provided by Eagle.

They may have tweeked the MAP parameters for EGR test as stated by Eagle.

cdoyle

My 92 Z28 does the exact same thing.
If I'm just driving around town, I don't recall the light coming on.

but yesterday I drove the car to work (50 miles each way) in the morning, no light came on. But in the afternoon, half way home the light came on.

When I got home, I shut the car off and then immediately restarted it. No light???
I checked the code today, and it's 32.

The car seems to run OK, the only thing I've noticed is the temp gauge doesn't seem to ever go past 195. Takes a while to get there, but that would trigger a 32 would it? Plus I would think that would just be a bad sending unit or gauge. Right?

The .pdf that was listed earlier was for a TBI. Is there anything specific for a TPI car I should be checking?

EagleMark

There is a TPI .pdf, TBI.pdf and V6 .pdf in doc folder here:
http://www.gearhead-efi.com/gearhead-efi/
That should cover all ThirdGens.

Each one will have specific information to diagnose code 32.

They are all basically the same, it is a test of EGR system, So all information above is carrect, but even a perfect EGR system can fail the test becauae it does not fall within guidlines of test. Free flowing exhaust as mentioned above can cause Code 32... but then again new stock cars in the day did too and were supposed to have a bin upgrade.

If anyone knows what this upgraded bin is or has one I am curious to look and see if it indeed just changed MAP paremeters in test?

EagleMark

Well that's what I was thinking because my LT1 $EE has a scaler for code 32 test and measure in MAP kpa.

But looking at a $42 hac it looks like an Integrater change? I don't have a hac for specific thirdgen that keep failing test... but from this it looks like $42 truck use a Back Pressure EGR and I think the Thirdgen is N EGR...

The other thing is qualifiers that have to be met to enable a code 32 test. Looks like it is not a MAP reading that fails the test but an Integrator count? Several hacs have test fro 30 sec to 90 sec and Integrator change from 4 to 8? So this would be a simple fix so code 32 is still active but fixed to pass test, but if I read this right it could be that fueling is off to begin with because as it closes EGR for test it is looking for Integrator change? Less integrator would pass test easier!

spoazzy1

Just wanted to give an update on this for anyone else coming in to this thread with similar issues. I want to let you know what I have done so far tohelp my issue.

I just did a thorough overhaul of my vacuum lines and chack valves, found some in pretty bad shape and still went ahead and replaced the ones that weren't. Figured I had the line, and the stuff is almost 23 years old already, it wasn't going to hurt. In fact alot of the line that "looked" ok, once I touched it or tried to disconnect it, crumbled and cracked in my hands. I also replaced the gas cap, and canister purge valve too, and plan to slowly work on the other valves and diaphrams in the vacuum circuit. Along with the addition of a brand new alternator, the car is finally running great, the high and rough idle has smoothed out, and although I still pull a code 32 when on the interstate, I am no longer seeing it during city driving. I do have aftermarket 3" exhaust and no cat anymore, so I know I may not be able to fully clear the code with programming, BUT the difference in how she is running is amazing.

jman1234

some tpi have a t at tb vacume line that dose run to egr sylinoid

THCARGUY

I have owned an 85 TA with the 5.0 TPI since new and a 91 TA with the 5.7 TPI since 1995. Both of these cars always set a code 32, usually after getting up to highway speeds for a few minutes, and have done this pretty much all their lives. I originally started replacing egr valves and solenoids but with no fix. I remember reading something many years ago in one of the magazines that mentioned this problem being associated with free flowing exhaust, which both of mine have. Ever since then I have not worrried about that code. I too get tired of seeing the check engine light but don't worry about it since it doesn't seem to hurt anything.

EagleMark

The same thing happens with 87-9x Chevy trucks. In $42 I added the code 32 test so it can be changed to pass the MAP kpa test yet still have EGR enabled and not just turn off the error 32.

Same reason for failing the test... free flowing exhaust!

airblaine

the ECM sends a signal to a relay that allows manifold vacuum to the EGR, the EGR opens and hot exhaust gasses from the cylinders flow thru the EGR body heating up the thermal element that the ECM wants to confirm the EGR opened. it does this with the thermal switch that is in the EGR body, if the ECM detects the changes (open or closed) with heat, then its ok, if not then it throws a 32 code.
test the relay by applying 12 volts if it clicks then it seems to work, blow air thru it no air should pass, apply 12 volts and air should pass thru.
test the EGR by pushing up on the diaphragm from the bottom then hold your finger over the vacuum port. does it move freely and hold pressure? if so its good.
with the whole assy together just disconnect the vacuum hose from the manifold and apply vacuum, see if it activates the EGR, it shouldn't. apply 12 volts to the switch does it apply vacuum to the EGR, the diaphragm should move up if this does not happen you have a good idea what might be bad. if all this works you have a wiring issue.