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Got the SES light on my drive home from work today, and when I pulled the code, it was 32.
Ok, not the best, not the worst, time to diagnose.
A little research turned up this, in a couple of threads;
Originally Posted by Cliff Harris
There are two ways to get an error code 32. When the ignition is turned on the ECM checks the EGR temperature switch to see if it's grounded (it should not be). If it sees a ground it sets error code 32.
The second way to get an error code 32 is when the ECM commands EGR and the EGR temperature switch does not send a ground to the ECM. The sequence goes like this: the ECM commands EGR by turning on the EGR solenoid. The EGR solenoid applies vacuum to the EGR valve. The EGR valve opens and hot exhaust gases flow through the EGR valve and into the intake manifold. The EGR temperature switch senses the hot exhaust gases flowing through the EGR pipe and closes, applying a ground to a pin in the ECM connector. If the ECM does not see that ground it sets error code 32. There is some time delay built in to all this and the ECM waits several minutes to see if the EGR temperature switch ground is there. That's why the SES light just seems to come on for no reason while you're driving down the road.
You can check for which error code you're seeing by clearing the error codes and then turning on the ignition. If you get an error code 32 right away, then it's caused by the first type of problem. Clear the error codes by disconnecting this connector for a second or so:
Thanks Cliff, for that write up.
So, based on that, cleared the codes turned the engine over and no SES light. Went for a drive of about twenty miles, got coolant and oil temperature into the 210 range, and still no SES light.
I assume that would have been warm enough to kick off the EGR valve. Is that correct?
The car only has 27k miles on it. I've put 1500 on since the tune up, and no issues until today.
Checked the vacuum lines as best I could without pulling off the intake, they all look brand new still, and if there were a hole in one of them, or the solenoid was flaky, I think that would have caused the error again.
The one thing I did find that was not looking good, was the EGR switch wire.
I've circled it in red in that pic, just to be sure it's what I think it is. Correct me if it isn't please?
Not sure if you can see it in the pic, but where the wire goes into the ceramic, there's a bit of crud built up, that looks almost like powdered ceramic. There's very small amounts.
It's the one part of the entire set of mechanisms that doesn't look entirely pristine though.
The wire also spins freely where it inserts into the ceramic. So, I am leaning toward wire in the process of breaking, as an explanation.
Given that I've changed spark plugs, spark plug wires, rotor and distributor cap, jostling and moved that thirty year old wire might be a contributor too.
Obviously will keep an eye on things, but am not going to have the time to pull things apart to the point where I can vacuum check the valve itself for a couple of weeks yet. So, wanted to see if you all had any thoughts, felt like telling me how mistaken I am, any of that kind of thing.
It would only set if I was on the highway at a nearly steady speed (cruise control) for about 10 minutes. I would never see it in town or for short trips even if warmed up.
The FSM for an '87 (your '90 is probably similar) gives the following conditions to set the code 32. On mine it was the EGR valve itself.
Sorry, I cut off the image too short. It says 4 minutes and I cut off the word minutes.
Good luck.
Last edited by QCVette; 06-21-2017 at 07:14 PM.
Reason: cut off picture
Yeah, got home, and my FSM has the exact same set of conditions. Was planning on driving it into work tomorrow to see if I can replicate the issue in any case, and that means about twenty minutes of highway time.
Thanks for that adjustment procedure. I'll definitely start there, should the code reoccur.
Naturally, nothing happened on the way to work this morning, and I definitely met the conditions listed in the FSM. However, it happened, the first time, on the way back from work yesterday, when it was above ninety degrees external temperature.
So, I'll see what happens under identical conditions this afternoon.
If the throttle closes, the 4 minute timer starts over. So the most likely conditions to set a 32 under is steady state cruise in light traffic. Using cruise control really helps keep the throttle from closing.
20 miles one way from home to work, on I75, and then back, cruise set to 75mph for a good ten minutes each way. My work hours have me travelling outside peak traffic times.
The trip home was pretty close to identical conditions to that under which the SES light turned on the first time. I'm fairly confident that I met all the conditions listed in the FSM.
You met the conditions for the diagnostic to run. The switch was closed, or it would have set 32.
A cross-check I've used is to disconnect the switch, and drive it again noting the conditions and duration it requires for the system to set 32. If you can intentionally set the code on your drive home from work, then you know your meeting the conditions for the diagnostic to run. Won't hurt the car any. Clear the code and plug the switch back in when you get home. Just another way to check your checking. Cheers.
Again, thanks. Will absolutely try that the next opportunity I have. Appreciate all the help.
06-21-2017, 06:04 PM
Code 32 diagnosis check (my logic good or not?)
