Service Engine Soon Light
Thread Starter
Drifting
Joined: Jul 2005
Posts: 1,891
Likes: 2
From: Baltimore MD
Service Engine Soon Light
In Maryland you are required to get an emissions test every two years. So I did the 95 this past Saturday, she passed the test with flying colors. On sunday I decided to take a cruise. Drove about 100 miles along the upper Chesapeake. On the way home I notice the "Service Engine Soon" light had come on. I do have a scanner for the OBD I/II. Havent' had time to run the codes. But what is the most common cause of this fault condition? According to the owner's manual it should only come on and stay on if a fault is detected. The car IS NOT running rough at all - like when an oxygen sensor went out and I had an over Rich condition - computer was actually dumping more fuel then required because of the lack of the feedback from the sensor I guess.
Thread Starter
Drifting
Joined: Jul 2005
Posts: 1,891
Likes: 2
From: Baltimore MD
I suppose but, the basic impression I get from the owner's manual is that is mainly deals with the fuel system and the emissions system.
Le Mans Master
Joined: Sep 2003
Posts: 5,874
Likes: 0
From: Littleton CO
The items in the owner's manual (I haven't looked in a long time) are likely just the things that can be easily corrected by the owner before deciding to take the car in for service. Tightening the fuel filler cap comes to mind.
Safety Car
Joined: Jan 2004
Posts: 3,783
Likes: 15
From: Northern California
Same thing just happend to my "91".
My Vette passed a California emmisions test with flying colors but, six months earlier the SES light lit up. It would only light up occassionally about once a week and then it started to come on once every night on the way home from work.
The trouble code was a #32 (EGR system).
The engine ran fine and if I shut the ignition off and restarted, the SES light would go out. I checked the EGR valve and EGR solenoid vacuum and everything was fine also, the "91" Vette doesn't use an EGR temperature switch like previous C4's.
After reading here on the forum, I found that the ECM could be bad so, I ordered a rebuilt ECM from Ecklers for $114 and so, far no more SES light!
My Vette passed a California emmisions test with flying colors but, six months earlier the SES light lit up. It would only light up occassionally about once a week and then it started to come on once every night on the way home from work.
The trouble code was a #32 (EGR system).
The engine ran fine and if I shut the ignition off and restarted, the SES light would go out. I checked the EGR valve and EGR solenoid vacuum and everything was fine also, the "91" Vette doesn't use an EGR temperature switch like previous C4's.
After reading here on the forum, I found that the ECM could be bad so, I ordered a rebuilt ECM from Ecklers for $114 and so, far no more SES light!
Last edited by GKK; Sep 17, 2007 at 11:05 AM.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Originally Posted by IrishJoker
I suppose but, the basic impression I get from the owner's manual is that is mainly deals with the fuel system and the emissions system.
RACE ON!!!
Thread Starter
Drifting
Joined: Jul 2005
Posts: 1,891
Likes: 2
From: Baltimore MD
Got a code 32 back from Actron Scanner - EGR valve. So I'll check all the connections form the EGR to the ECM and all the vacuum lines, then reset the Service Engine Soon light and see what happens.
