transmission

O/D light will flash if the electronic pressure control (EPC) solenoid circuit is open, shorted to battery, ground or a fault has been detected in a monitored sensor used for transmission operation.

I could not find any information in our database as to the diagnostics of the EPC.

Is there any other engine trouble codes?

Thanks for the reply and help KHLow2008. This transmission has a solenoid block that has been revised twice in design. I did replace it with a new one but unsure which revision. I swapped out the three identical pressure sensors on top of the transmision to seeing any change in the symptons but still after 3 miles down the freeway O/D light flashes and message center says to check transmission. It does the same with the O/D off but however doesn't when left in 3rd gear or if not 60mph or above for three miles. Also if shut off and restarted it goes off til 3 more miles.

Seems to be a problem with the OD gear and if no codes are available, the only way is to plug in a scan tool and monitor the running conditions and retrieve the freeze frame data for analysis when problem occurs.

I will do additional research on the problem see if I can come up with anything.

Ok I just wanted to thank you again for the help and let you know that my problem stopped occouring. When I finally got my scan tool back from who I lent it to I didn't get a chance to monitor it because it hasn't happened since. I did read that when you replace the epc solenoid that you should submerge it in trans fluid to purge out the air. I did not do this and maybe thats what was cause the light and eventually it purged the air out itself.

Glad to know the problem has been resolved.

I believe it shuld not be the presence of air but rather the EPC could be stuck and has since worked itself free.

Have a nice day.