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Ask GM Tech (Cam) Your Own Question
GM Tech (Cam)
GM Tech (Cam), Chevy Technician
Category: Chevy
Satisfied Customers: 29522
Experience:  GM Grand Master Technician 2007. 14 years experience.
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I have a 2003 chevy silverado that wont start and my mechanic

Customer Question

I have a 2003 chevy silverado that wont start and my mechanic doesnt know what is wrong with it he hooked up the computer to it and it say something about the security alarm he checked with chevy and they say that the security alarm is keeping it from starting do you know how to fix this i hear it is common problem
Submitted: 7 years ago.
Category: Chevy
Expert:  GM Tech (Cam) replied 7 years ago.

WElcome. If the security is keeping it from starting, then lets try a relearn and see what happens. If this works, then it may be the passlock sensor which is in the ignition cylinder housing.

Turn ON the ignition, with the engine OFF.

Attempt to start the engine, then release the key to ON (vehicle will not start).

Observe the SECURITY telltale, after approximately 10 minutes the telltale will turn OFF.

Turn OFF the ignition, and wait 5 seconds.

Repeat steps 1 through 4 two more times for a total of 3 cycles/30 minutes ( the vehicle is now ready to relearn the Passlock Sensor Data Code and/or passwords on the next ignition switch transition from OFF to CRANK).

Important: The vehicle learns the Passlock Sensor Data Code and/or password XXXXX the next ignition switch transition from OFF to CRANK. You must turn the ignition OFF before attempting to start the vehicle.

 

Start the engine (the vehicle has now learned the Passlock Sensor Data Code and/or password).

Customer: replied 7 years ago.

they have tried this and nothing

 

Expert:  GM Tech (Cam) replied 7 years ago.
OK, have they checked for spark and fuel pressure?
Customer: replied 7 years ago.
yes all is fine
Expert:  GM Tech (Cam) replied 7 years ago.
What is the code?
Customer: replied 7 years ago.

I cant remember the code but the answer you just gave me in the beggining is what it says to do and thats what they did but its not working

 

Expert:  GM Tech (Cam) replied 7 years ago.
OK, If that does not work, then there is one of 3 issues. First is the Wiring, second the sensor and third the Body control module.