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Code 32 mystery

John '85

Well-known member
Mar 22, 2006
Fremont CA
1985 Red Coupe TKO500 Z51
Ok, all you code 32 head bangers, I have a good one for you. I have always had a check engine light come on at the same time everyday during my commute to work, and on the way home. With the little GM code reader 'jumper' in the ALDL, the light flashes 32.

I borrow a friend's AutoExray EZ scan 5000 and it shows, no codes! even when I get the light again, at the same location on my drive, I plug in the EZ Scan 5000, and 'no codes'!!!

So I plug in the EZ Scan and leave it powered up on my drive, to look at the parameters along the way. Guess what, the check engine light did not appear during the drive! (the first time it didnt appear!)

When I park in the lot at work, in goes the GM code reader, and you guessed it, light flashes 32.

So frustrating, it makes my ass want to chew Tobacco!

Car runs fine, all parameters are normal.


Well-known member
Dec 19, 2001
sonoma ca usa
2004 C5 coupe, MSGM & 2014 Cad SRX Crystal red
I have disconnected the battery numerous times, that should clear any history. Right??

Don't know about 85"s, but that won't work for the later model's 95, etc. Someone will come up with some help.


Code 32 is the EGR circuit

In the Haynes repair manual it has a code chart which says that code 32 is the EGR circuit. It continues to say check vacuum source and all vacuum lines. Check the electrical connectors at the ECM and EGR valve. Replace the EGR valve. If the car is running OK, I would just leave it alone, I have the same code on mine. ;)


Well-known member
Dec 31, 2002
1986 Pace Car
Code 32

Click here


New member
Sep 2, 2007
On the passenger side of the TPI intake, just behind the fuel rail, there is
a sensor (1pc - pn# 14087415) in the EGR tube which runs from the exhaust
manifold to the intake. The sensor has a single wire and consists of a ceramic
insulator captured in a metal body like a spark plug.

Check this sensor, it was the culprit for the Code 32's on my '89.

Mine felt loose where the wire enters the ceramic core and on inspection, the
threaded insert had begun to come out. (The hood release cable for the
passenger side was routed right beside the sensor and may have put pressure
on the connector each time the hood was opened.) Replacement of the
sensor takes about five minutes: disconnect the sensor wire, use a box end
wrench to remove the old one and then reverse these steps to insert the
new sensor.

This tip about the sensor is credited to Gordon Killebrew, of "For Your Car Inc".
It is mentioned in one of his publications - "Top 50 Questions From Corvette
Owners and Dealers" Either Vol 1 or Vol 2.



Well-known member
Mar 28, 2007
The 85 EGR temp. sensor is on the EGR valve 86 to 89 sensors are on an EGR crossover pipe the runs from the right side exhaust manifold to the intake but 85 used iron heads which have an exhaust cross over in the heads so all that was needed was ports in the intake to pull exhaust gases into the intake with the EGR valve so I suspect that is were the problems lies. In 85 to 89 the EGR is tested by the ECM by use of heat switch hot gases going through either the cross over (in 86-89) or EGR valve(85) close contacts in the sensor to confirm operation if the switch remains open after the ECM has been operating the EGR it will set a 32 for inoperation. And yes this is a timing thing so it would not suprise me to hear it always sets a the same time during your trip probably a little while after doing some highway driving. Some scan tools will have rread out for this sensor and you can check to see if it works. Vacuumn would be the first thing to check. If you had a scan tool that was bi-directional you could comand the EGR on and by uses of a small mirror check it's operation. With out a scan tool try unhocking the EGR solnoid and bringing the idle up to around 2,000rpms with the use of a mirror you can verify it's operation this is a quick check and what it doesn't test is the solenoid's operation but it does check valcuumn and the valve. The ECM turns the solenoid off to turn the EGR on.

David Fulcher

Tin butcher

I had the same trouble with my '85. The car would run fine, but set a code 32 everytime I drove it. The previous owner must have had the same trouble - it had a new EGR valve and EGR switch. I ran thru the tests in the shop manual - everything checked OK. I put a check valve (NAPA #730-1347) in the vacuum line from the plenum to the EGR solenoid. No more code 32 - unless I take the check valve out!


Well-known member
Nov 23, 2001
Savannah, GA, USA
87 Silver Coupe Way over 200k miles
It is a time/distance thing as i remember. like 30mins after the key is on and engine running it does the system test. It opens the egr and looks for a temp change.
My guess with the code scanner plugged in the system didn't do the diag. test
like it was memtioned those sensors are famously wacky.
Mine has turned on the light. Just some wiggling of the sensor has satisfied it for the past couple of years.
Look at the diagnostic chart and make sure all the solonoids and vacuum lines are in good shape.
It may have blocked egr passages if all else is good


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