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Ask GM Tech (Cam) Your Own Question
GM Tech (Cam)
GM Tech (Cam), Chevy Technician
Category: Chevy
Satisfied Customers: 15201
Experience:  GM Grand Master Technician 2007. 14 years experience.
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What would cause code 308 top come on a Silverado 2002

Customer Question

what would cause code 308 top come on a Silverado 2002
Submitted: 1 year ago.
Category: Chevy
Expert:  Jared D replied 1 year ago.

To clarify, is the code a P0308?

Customer: replied 1 year ago.
code 308 thik it has something to do with trans or transfer
Customer: replied 1 year ago.
we put aoverhauled motor in it then he put a big thing that I think had to due with modules and before he put that on the truck run itwill run now but it wont move
Expert:  Jared D replied 1 year ago.

If the code is a C0308 then it would be a transfer case encoder motor problem. The transfer case encoder motor shifts the transfer case into 4wd when activated by the switch. This motor gets stuck or goes bad and triggers a fault code. The most common solution is to replace the motor.

Do you plan to replace it yourself?

Expert:  Jared D replied 1 year ago.

If it won't move the transfer case could be stuck in neutral because of a bad encoder.

Expert:  Jared D replied 1 year ago.

Here is how you can try to get it to shift manually:

1. Disconnect the module from behind the left side of the dash (behind the headlight switch).

2. Jump the Tan (1569) wire at terminal E1 of the Black connector to ground.

3. Jump the Orange (1640) wire at terminal D to the Red (1553) wire at terminal B.

4. Jump the Black (2150) wire at terminal C to the Black (1552) wire at terminal A.

5. Check for the transfer case to shift. Reverse polarity of the Red (1553) and the Black (1552) wires, and check for the transfer case motor to change directions.

6. If the transfer case does not shift, repeat the procedure using the same wire colors and the motor on the transfer case.