EGR Question
Thread Starter
Instructor
Joined: Jan 2005
Posts: 145
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From: Ft.Worth Texas
EGR Question
My 91 keeps getting a code 32,I have gone through all the tests,solenoid ok,EGR new,ok, and all lines check out good.Question is ,What tells the ECM what the EGR is doing.Is it the Map sensor or is it the Manifold Temp Sensor?The SES light comes on only after I am on the freeway for about 5 minutes.When I get off and park the SES light goes away untill I get on the freeway again.Any help would be appriciated.
Thanks,
Randall.
Thanks,
Randall.
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
A little temperature switch that's in a tube from the right header to the intake. The ECM is supplying voltage to this switch whenever the ignition switch is in the run position. When EGR is commanded, exhaust flows through the tube and the heat from that exhaust grounds the switch. The voltage at the ECM drops to 0 which is what the ECM expects it to do. The ECM has no idea if the EGR valve actually worked or opened fully - it assumes that it did. If the voltage doesn't drop - or some other voltage source is shorted to this switch, you get a 32. Easiest to check with a scanner though some don't have the capability to read whether the switch is open or closed. Absent that, check wiring - especially the connector that's often buried inside of the injector harness. Or just fork over the bucks for a new one. When removing, it often helps to have it heated up, so before you attempt to wrench it off, run the engine until the header is nice and toasty.
Thread Starter
Instructor
Joined: Jan 2005
Posts: 145
Likes: 0
From: Ft.Worth Texas
A little temperature switch that's in a tube from the right header to the intake. The ECM is supplying voltage to this switch whenever the ignition switch is in the run position. When EGR is commanded, exhaust flows through the tube and the heat from that exhaust grounds the switch. The voltage at the ECM drops to 0 which is what the ECM expects it to do. The ECM has no idea if the EGR valve actually worked or opened fully - it assumes that it did. If the voltage doesn't drop - or some other voltage source is shorted to this switch, you get a 32. Easiest to check with a scanner though some don't have the capability to read whether the switch is open or closed. Absent that, check wiring - especially the connector that's often buried inside of the injector harness. Or just fork over the bucks for a new one. When removing, it often helps to have it heated up, so before you attempt to wrench it off, run the engine until the header is nice and toasty.
Thread Starter
Instructor
Joined: Jan 2005
Posts: 145
Likes: 0
From: Ft.Worth Texas
There are no wires anywhere close to that tube or any conectors unpluged.When you say the right side you do mean the passenger side,right? Ihave looked all through the manuels and they have no referance to this switch.Perhaps you could please tell me what it's tech name is.
Thanks .
Randall
Thanks .
Randall
Le Mans Master
Joined: Sep 2006
Posts: 6,050
Likes: 147
From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
code 32
1. did you put headers on it?
2. did it ever run ok without a code 32?
3. did you break off the little tab that holds the connector on the EGR solenoid?
My tab broke off a couple years ago, and the connector comes out once in a while. I ty-wrapped it in, and no more problems.
2. did it ever run ok without a code 32?
3. did you break off the little tab that holds the connector on the EGR solenoid?
My tab broke off a couple years ago, and the connector comes out once in a while. I ty-wrapped it in, and no more problems.
Thread Starter
Instructor
Joined: Jan 2005
Posts: 145
Likes: 0
From: Ft.Worth Texas
1. did you put headers on it?
2. did it ever run ok without a code 32?
3. did you break off the little tab that holds the connector on the EGR solenoid?
My tab broke off a couple years ago, and the connector comes out once in a while. I ty-wrapped it in, and no more problems.
2. did it ever run ok without a code 32?
3. did you break off the little tab that holds the connector on the EGR solenoid?
My tab broke off a couple years ago, and the connector comes out once in a while. I ty-wrapped it in, and no more problems.
2,Yes it did
3,replaced the connector and solinoid,all check good.
Everything in diognostic mode works fine.Just when I drive on freeway for 5-8 minutes I get the light.
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Thread Starter
Instructor
Joined: Jan 2005
Posts: 145
Likes: 0
From: Ft.Worth Texas
Thanks
Safety Car
Joined: Jan 2004
Posts: 3,783
Likes: 15
From: Northern California
Same thing happens on my "91".
Every couple of days, only when driving home on the freeway for about 5 minutes the service engine light will come on. The only code is a 32. If I shut the engine off and restart it the service engine light goes out and never comes back on.
I just passed an emmisions test with flying colors and the engine runs fine. The "91" does not have an EGR Temperature switch in the egr tube like my "89" did.
I also, don't know what to check for since everything seems to check out ok (egr valve, solenoid, vacuum lines ). This problem is intermittent and hasn't affected the engines performance, it's just annoying when the bright service engine light suddenly comes on.
Every couple of days, only when driving home on the freeway for about 5 minutes the service engine light will come on. The only code is a 32. If I shut the engine off and restart it the service engine light goes out and never comes back on.
I just passed an emmisions test with flying colors and the engine runs fine. The "91" does not have an EGR Temperature switch in the egr tube like my "89" did.
I also, don't know what to check for since everything seems to check out ok (egr valve, solenoid, vacuum lines ). This problem is intermittent and hasn't affected the engines performance, it's just annoying when the bright service engine light suddenly comes on.
Last edited by GKK; Jun 25, 2007 at 11:03 AM.
Race Director
Joined: Sep 2000
Posts: 17,298
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From: The Top of Utah
Originally Posted by rcr103
Ihave looked all through the manuels and they have no referance to this switch.Thanks .
Randall
Randall
RACE ON!!!
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
Yikes - always thought all of the L98's were the same. More modern versions have the PCM looking at the Integrator to tell if the event took place. The PCM turns the valve off for a nano second and looks to see if the Integrator swings lean. As it turns back on, that value drops. If it doesn't, trouble code time. As pointed out, your Shop Manual will outline what it's got - Section 6E: Driveability & Emissions.