Service Engine Soon

[my_1_corsica]

Hi! I have a 1991 Chevy Corsica, 4 cylinder - 113000 miles, and i have a 'Service Engine Soon' problem : I checked the car and it has an error 34. I have replaced my ECM three weeks ago, i just replaced MAP sensor and oxygen sensor but my car still does the same problem, even more frequently. The car runs smooth on a neat road, but any shaking induced by the road (like holes in pavement or a higher portion of road) makes the engine to stop for a few seconds (1-5) ... the Service Engine Soon light appears and the engine continues to run and after a while the light disappears sometimes, if the SES light stays on i observed that if i turn off the engine and then turn it on the light disappears. Sometimes the light appears and the engine stops while waiting at a stop. I don't know what's wrong with it. Please help!

[rejean]

Hi there
I would like to know if you've had the problem solve and how?? I have the exact same probleme?? Can you help??

Thanks
rej

[my_1_corsica]

I did a car check at MIDAS and they told me that the problem is the ECM. I had my mechanic change the ECM and I had no more problems like that. Now it runs very good.

[rejean]

Thanks

I had the ecm replace and it works fine now. I was told by my mechanic that there was small water leak that reach my my ecm and that was the source of the problem.

thanks rej

[Wicorsica]

did you try changing the egr valve cuz that happen to mine and thats what i had to change.

[acider]

I had the same problem and the answer was in a bad contact to the computer on the passanger side

[bellguy24]

A common problem when these cars get older is that water will leak into the ECM thru the wiring harness that runs from engine compartment thru the firewall. I sealed around the harness with some RTV silicone and have not had any problems. (200K)