Reseting SES Light
Instructions on How to Reset the LS1 ECM
Submitted by: Scott Harroff
This is intended to reset that aggravating 'Service Engine Soon' light so many of us seem to see. The light is normally set due to a loose gas cap or a high frequency error on the mass air flow sensor in front of the intake manifold. If the light persists, you may want to have you car checked by a GM dealer. It may be a good idea to remove your K&N air filter, and replace it with the stock filter or equivalent before your visit to the dealer. Dealers, in the past, have been known to blame the MAS error on excessive oil in the K&N leaking onto the MAS. If the fuses aren't removed in this procedure, the codes will be stored in the ECM until the fuses are removed, or the dealer clears them with a scan tool. Rumors have it that stored codes retard timing and spark ignition which will hender the performance of you LS1.
1. Turn key on but don't start car.
2. Pull PCM BAT and PCM IGN fuses in engine compartment.
3. Wait a few minutes.
4. Turn ignition off.
5. Replace fuses.
It will take the car a while to relearn the fuel and timing curves so don't worry about a temporary performance loss.

I still say disconnect the battery.
Why would you want to disconnect the Battery for 10 minutes when it takes you 2 minutes to reset your ECM. I have done it several times and it works. I still say reset the ECM. Trending Topics
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