I have been experiencing an intermittent code 32 which I believe to be due to the EGR Temperature Switch (which went out of production in 2009 & cannot be found at a price I want to pay).

A week or two ago I found this link & posted it in another EGR temp switch thread with the caveat that I'd never tried it myself:

http://chevythunder.com/fuel%20injec...temp%20sw..htm

A forum member PM'ed me that he'd found this useful. I asked some questions and encouraged him to post his experience. He has chosen to remain anonymous but PM'ed the following, which I hope he doesn't mind my forwarding:

"The switch is one part threaded into another. The wire is soldered into the inner part. I think there is a hex on the inner part just above the threads. The outer part is threaded into the EGR pipe. On mine the inner part can be screwed in and out by hand; it's just a matter of not breaking the wire. It's a bi-metal switch and the two parts have contacts that touch when heated, letting the voltage in the wire go to ground. The article shows how to calibrate the temperature at which they touch, but it's not that difficult to find a happy place just using trial and error. I had made the mistake of screwing the two parts together tight. Once loosened a coupe of turns all was well."

I have a cold & skipped my fiddle lesson this morning. While laying about croaking like a frog, I decided to see if I could adjust my switch following his advice. I was surprised to find it was quite easy to turn the shaft of the switch. It required a pair of needle nose pliers to get it started but then was easy to turn by hand as stated above. I turned it one or two revolutions & started the engine and the SES light came on---the usual symptom. I then disconnected the wire & turned it till about 1/16" to 3/32" of the threads were exposed, hooked up my laptop to the ALDL connector and datalogged a short drive using Datamaster software.

So far, everything seems fine. The SES light did not come on, the EGR valve did switch, and the EGR diagnostic status changed state as the engine warmed up.

Here is a screen capture at t=152.8 seconds showing the EGR has been switching but the EGR diagnostic in state 1 (which I hope means the voltage on circuit 935 is high, i.e the temp switch is open).



Here is a screen shot at t=152.8 seconds showing the diagnostic in state 0, which hopefully means the temp switch has closed:



At this point all this proves is that what I did has done no harm. I won't know that it has solved my code 32 problem for a week or so & will post an update as I learn more.

My thanks to the member who PM'ed me. Please step forward and take the credit for trying this first.

Oh...I should mention: Disconnecting the wire is easy, the connector just pulls apart. Getting it back together is tricky. There isn't much room for big hands and it's awfully hard to see. I used a mirror to reflect sunlight into the area of interest.

 

Update:

It's been almost a week now with no Service Engine Soon light. I believe this problem is solved.

If you're getting a code 32 right after starting & don't have any obvious shorts or other problems this may be the fix for you.

 

I get a code 32 after driving for 10 mins on the highway

 

The only "happy" place for the switch is too ground when EGR is commanded and that's Closed Loop, steady cruise. The ECM senses the voltage drop and that prevents the Code. Yours isn't doing that meaning that: 1. The Switch is dead. 2. The EGR didn't take place when commanded. The latter is the more frequent cause usually because the solenoid that allows vacuum to open the EGR valve is broken OR the wiring is open OR the vacuum lines are broken. I'd started by checking the vacuum lines.

 

The factory service manual has a diagnostic chart you can follow to figure out what's wrong. To be honest I didn't actually go through the procedure, but with the manual and a scanner (Datamaster) it was fairly ovious what was going on in my case.

A 10 minute delay is much longer than I was experiencing which suggests, to me, the switch isn't closing when it should or the egr itself isn't working right (i.e. what SunCr said).

Someone posted the code 32 diagnostic chart for an '87 a while back. I couldnt find that original thread but still have a copy I'd be glad to email to you if you don't have the FSM---PM me if you want it.

 

That link has been truncated (it's no good)...Do you have the original link somewhere???

 

The forum is truncating the link when it wraps it in the url coding. Here it is wrapped in quotes. Copy and paste it (without the quotes) into your browser address and you can get to it

"http://chevythunder.com/fuel%20injection%20egr%20temp%20sw..htm"

Oh, and since we're updating this thread, I should mention that the temp switch is available for sale again from a couple of the forum vendors.

 

This link works...

http://chevythunder.com/fuel injection egr temp sw..htm

...even though Chevy Thunder put too many periods in the URL...

BTW: I looked in my spare parts bin and found 84 - 89 EGR TEMP SENSOR SWITCH 1408 7415 which Google shows as still a good number, and which is listed at GM NOS Parts at $125.00...

 

Thanks for posting the link.

It's about half that price on corvette central & probably similarly priced on other forum vendors.

It wasn't available at any of the vendors when I was messing with it. I could only find it on ebay for $400 to $600!!! That's what gave me the nerve to try adjusting it.

 

Yes. I was getting code 32's on start-up. Unscrewing the temp switch shaft 2 to 3 turns solved the problem. Datalogs indicated EGR function after the fix & code 32's have never returned.

 

I also had a code 32 at cold start and, after reading this thread, unscrewed the top of the EGR Temp Sensor a few turns. It soved the problem and passe New Jersey Emissions, so I'm very pleased.
It's great to have a repair that doesn't cost anything.
Thanks for the great advice!

 

You're welcome.

 

I remember that stupid little switch. I broke the one on my 85 trying to remove it so I could unbolt the EGR valve. I figured it was no big deal and I could just get a replacement. WRONG

I looked for 2 weeks online and locally and found nothing. I finally was able to get a cross reference to a Standard part number and found one in a local autoparts store. When they said they had it, I was prepared to pay almost anything. When we told me the price, I was floored! $15! I then asked how many more he had, he told me it was the last one. I thanked him and while still on the phone, texted my wife to pick it up for me.

 

They are in production again, but not for $15.
Want to share the standard #?

 

I did find this on the MAM site:

https://www.mamotorworks.com/corvett...329-11663.html

The original part AC/Delco part number for the 85 is 212-337. The Standard Part # should be ETS2. I heard the ones for the F-body cars with work too (ETS3 I believe).