So I've had a recurring issue with my 03 Monte lately. I will get in the car, crank it up, drive, park, and turn it off. Then a half hour later, I'll be stranded in the parking lot bc it will not crank. I cant even get the doors to unlock, no lights on the dash....NOTHING. Out of nowhere, about two to three hours later, itll crank like a champ. I thought i had a bad cell the first time it happened cuz i jumped it off, replaced the battery and it happened three days later with the new battery. Battery checks out fine and it wouldnt be that anyways if it will crank after a time period. Im thinking it may be my terminal wires, (terminals have all been completly cleaned), or even a computer issue. Thoughts???

 

Sounds like it could be BCM issues beginning and it will get worse in time if it is.

 

sadly thats what i was afraid of

 

Ive been reading threads from a while back and people seem to be having the same problem and it turns out to be the lock cylinder thats bad.

 

Well then...if thats what you think it may be then change out the lock cylinder or just change the complete unit on your dash. My Monte was doing the same thing yours is doing and it was the BCM and not a lock cylinder...It got worse as i let it go...even the so called ASE mechanics at my chevy dealer could not find the problem using their scanner and plugging into the car...there was no code stored and they also checked the ignition switch if thats what you mean by lock on your car and not the door locks.I made a lucky guess because i read about all the BCM problems people were having here and strange electrical issues with their Montes so i had the great ASE mechanics change the BCM and re-program it for my vehicle and i havent had a problem with it since FEB 2011...but that was my problem and may be not your problem but the issues were exactly the same..Good Luck!