Diagnostic Aids

WARNING: This page is about a different car, the 2002 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.

When the class 2 serial data circuit is shorted to ground, U1300 will be set. Refer to DTC U1300, U1301, Or U1305 (Generic Short DTC) .
When the class 2 serial data circuit is shorted to B+, U1301 will be set. Refer to DTC U1300, U1301, Or U1305 (Generic Short DTC) .
Disconnecting modules and turning the ignition switch to RUN may cause DTCs in the vehicle modules. Check for DTCs in each module upon completion of the required repair.