EGR testing
Thread Starter
Race Director
Joined: Apr 1999
Posts: 15,156
Likes: 477
From: NM
EGR testing
I have been getting an intermident "Service Engine Soon" light. Pulled the codes today and had a history code 32 which is EGR System Error. I looked at the testing procedure in the manual and got totaly lost, may as well have been written in Greek. Can anyone provide an easy way to test the EGR system? If the EGR should need to be replaced, what is involved since it is under the intake plenum?
Got to get this thing running right since it is going to be making a 20 hour trip next week from Austin TX to the Chicago area for the Bloomington show.
tom...
Got to get this thing running right since it is going to be making a 20 hour trip next week from Austin TX to the Chicago area for the Bloomington show.
tom...
Burning Brakes
Joined: Feb 2000
Posts: 958
Likes: 1
From: SF Bay area, CA USA
Re: EGR testing (Tom73)
If your year has the EGR temp switch ( sensor in the top of the tube that comes of the ehaust on the passenger side, the wire connects behind the distributor) you might replace it. It costs about $12 and is a common problem. Other than that go by the steps listed in the shop manual. If you don't have a GM shop manual get on. The procedures really aren't very difficult.
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: EGR testing (Tom73)
This test involves using the EGR Solenoid to activate the EGR valve and then verifying the EGR Temp feedback.
First verify all vacuum lines are in tact.
The EGR solenoid is under the front of the plenum and has two vacuum lines and an electrical connector, the EGR valve is atop the intake base under the rear of the plenum, the EGR Temp sw is atop the upper EGR pipe.
Open the connector to the EGR solenoid and connect a jumper across solenoid contacts with the engine at idle. You should see the EGR valve bellows move. With a DMM connected between the EGR Temp switch wire and ground you should soon see that voltage go from +5Vdc to 0.
When my '88 threw that code a copla years ago it was the EGR valve, which still isn't an expensive item. However, when done at a dealer it came to over $500 with diagnostic labor charges.
First verify all vacuum lines are in tact.
The EGR solenoid is under the front of the plenum and has two vacuum lines and an electrical connector, the EGR valve is atop the intake base under the rear of the plenum, the EGR Temp sw is atop the upper EGR pipe.
Open the connector to the EGR solenoid and connect a jumper across solenoid contacts with the engine at idle. You should see the EGR valve bellows move. With a DMM connected between the EGR Temp switch wire and ground you should soon see that voltage go from +5Vdc to 0.
When my '88 threw that code a copla years ago it was the EGR valve, which still isn't an expensive item. However, when done at a dealer it came to over $500 with diagnostic labor charges.
