About a month ago I got the code 32 which is the EGR system. I only get it in highway driving conditions and not in town driving condition which is my main driving condition. Last night was the 2nd or 3rd time in about a month that I have gotten it. The code goes away overnight so the next day I no longer have the SES light when I start the car.

Any suggestions on where to look or what to look for? Any simple test I can do without removing half the car

Since I only get it on highway driving conditions could that mean the EGR valve itself is dirty and/or stuck or the diaphragm is torn?

Car is a 1989 corvette

Any and all help is appreciated.

Thanks, Stephen

 

Check the connection on the wire to the EGR temp switch on the crossover from the exh manifold , typically breaks

In explanation ,
your EGR could be working fine , it may be that the above switch that sends the signal to the ECM
that EGR is actually working when the ECM commands it is playing up so the ECM puts up a code for a EGR fault


To check the electrical side of EGR operation
http://www.chevythunder.com/egr_code_32.htm

 

same symptoms with my 89. i learned on here that if the code sets immediately it is the egr solenoid. if it sets after a few miles it is the egr valve. picked up a valve at oreillys and took the old one off and it would not hold a vacuum. replace valve and no more codes.

 

Thanks for the info I am trying to gather up as much as possible before monday when I start to try and diagnose it.

I know sometimes the diaphragm ruptures and that can cause it, do you happen to know if I can vacuum test it while on the vehicle and see if it will loose vacuum or does it have to be off vehicle to do that test?

Thanks for the help, what you gave me should be very useful.

Thanks, Stephen

 

Was yours after a few miles of highway driving or in-town driving? Mine only comes on after around 7-10 miles of highway driving, 60mph or more.

Do you know if I can vacuum test the valve while on the car to see if it looses vacuum or not, or is it an only off the car test?

Thanks, Stephen

 

The point I was making was that you first have to determine if you have a real EGR fault or a EGR working, indication to the ECM fault.

It is very common to have a fault with the switch / wiring that has nothing to do with the EGR actually working
and does not require dismantling the intake or a vac test

 

This applies to L98s that have an EGR temperature switch.

There are two different ways to get an error code 32. I don't know why the engineers didn't give them different numbers, but we're stuck with it.

Error code 32A (as some people call it -- I think Ward Spoonemore was the first): When the ignition is turned on the ECM checks the EGR temperature switch to see if the input is grounded. If it IS grounded (it shouldn't be) then the ECM sets error code 32.

Error code 32B (This is what I call the "cruisin' down the road" error code 32): (All numbers approximate) When the coolant temperature is higher than 194°F and the TPS stays between 6% and 30% for more than 4 minutes, then the ECM commands EGR. It does that by grounding one side of the EGR solenoid. The EGR solenoid applies ported vacuum from the throttle body to the EGR valve. The EGR valve opens, which allows exhaust gases to go from the exhaust manifold through the EGR tube, through the intake manifold, through the small runner tube and into the plenum. When the hot exhaust gases pass through the EGR tube the EGR temperature switch closes, which grounds the input to the ECM. If the ECM does NOT see that ground (meaning the EGR SYSTEM (<-- note caps) is not working) then it sets error code 32.

What will typically happen is that you're "cruisin' down the road" and the SES light will just come on for no apparent reason. There is no change in the way the engine is running or any other indication that something is wrong. If you shut off the ignition and then restart the SES light will be out.

The whole EGR system must be working to keep that error code 32 from happening. If any one part in the system doesn't work then you get the error. In many cases people replace the EGR temperature switch just because it's easy and relatively cheap. In my case the EGR solenoid failed, which caused the EGR valve to freeze up from non-use.

Watch out for new EGR valves that have a bad vacuum diaphragm. It happened to me and several others who have posted here. Fortunately I tested mine with a vacuum pump before I put it on the car.

 

mine would come on while on the hway. 25 miles into a 35 mi commute. with 100k miles i went ahead and bought the egr valve on the way home so that i would have it when i took the phlenum off. i did not attempt to test it until after i got it off the car, so i dont know if you can while still on the car.

maybe you can follow the vacuum line away from the valve and find a place that you can seperate the line and apply vacuum.

 

Ok, I should be checking it today. On the switch am I just looking for broken/screwed up looking wire/wires?

And hopefully it is that cause I don't wanna take off the plenum, because then I will want to fix a million other things, I think everyone knows how that goes

Also on that flow chart you sent me, it says to "ground the ALDL" a few times. I was wondering when it said to ground the ALDL what pins was it wanting me to ground?

Also it says "connect a voltmeter between harness term and ground" Does that mean just connect one probe to the harness and the other to a nice ground location on the car?

Sorry, not great with electrical.

Thanks, Stephen

 

Mine is definitely the code 32b as it only come on at highway driving not the start of the car. So, from what I understand since it is code 32b it could be anything in the car to due with EGR even the EGR temp switch? And all I need to do it follow the diagnostic flow chart given above?

Thanks for the info, Stephen

 

Same problem my previous 89 had.

Just replace the EGR valve and it'll be fixed.

Your Vette is 25 years old and parts don't last forever...




.

 

I would love for that to be the problem and I could just replace and fix, but I don't have a ton of money and don't feel like buying something that might or might not fix the problem.

Thanks anyway though. Maybe that will be the problem and you could say "I told you so"

 

Had the 32b a while back and changed out the valve. Was fine for a few miles then the light again appeared. Changed the valve again and has been fine ever since.

 

Buy the OEM EGR valve since, their are different types of egr valves and your 89 Vette uses the "Positive Back Pressure" type valve.






.

 

I think If I buy one it will probably be the BWD valve from O'Reilly if that is what is wrong. It looks the same, although looks don't mean everything, and is listed as an exact fit on a few different websites and parts suppliers. And I also get discounts with them. If it is anything else I will most likely be ordering through corvette central as no local places have anything but the EGR valve.

 

In which case you will still have the code for little time wasted
Many have dismantled the car to fix the EGR valve only to find it fine and the cause of the code was the temp switch

 

Not to high jack the thread but does anyone have the diagnostics for a 91 that does not have the temp switch? I have the "32b" code but I have no temp switch..

This seems to be a good diagnostic for the pre-90 with the temp switch.
http://members.shaw.ca/corvette86/Code%2032.pdf

 

Note, that your 91 Vette uses a "Positive Back Pressure" EGR Valve not, the Negative back pressure egr valve type described in your link, which operates differently.

 

The only difference in your system is that the EGR temperature switch function is replaced by a change in pressure in the plenum, which is measured by the MAP sensor.

You need to be looking at the EGR solenoid, EGR valve, vacuum connections and electrical connection to the EGR solenoid.

 

That's why you need to troubleshoot the system rather than just wasting time and money by throwing parts at it.

One of the problems with the error code 32B is that it happens rarely, so it's difficult to tell if you've fixed it or not.

I currently have one of those myself.

I haven't seen the SES light in weeks (when I went down the freeway to the Corvette club meeting). I drive this car every day but it's mostly around town and short hops (10 miles or so) on the freeway. Other priorities are taking precedence right now...

Just FYI: my EGR solenoid measured 28 ohms, in case anybody is checking.