B2708 Gearshift Unlock Circuit high

Diagnostic Chart:

Schematic:

CIRCUIT DESCRIPTION
The Body Control Module (BCM) controls the A/T shift lock control solenoid. Positive voltage is supplied through the ERLS fuse through circuit 439 to terminal B of the A/T shift lock control solenoid. The BCM supplies a ground signal to the solenoid through circuit 323 to terminal A of the solenoid. When the brake pedal is depressed, the BCM removes the ground signal allowing the solenoid to disengage. This action allows the vehicle to be shifted out of park.

CONDITIONS FOR RUNNING THE DTC
^ The ignition switch is in the on position.
^ The brake pedal is depressed.

CONDITIONS FOR SETTING THE DTC
The shift lock control circuit is shorted to battery positive voltage for 1 second.

ACTION TAKEN WHEN THE DTC SETS
The BCM disables the A/T shift lock control output for the remainder of the ignition cycle.

CONDITIONS FOR CLEARING THE DTC
^ A current DTC B2708 will clear when the malfunction is no longer present and the ignition switch is cycled.
^ All BCM history codes will clear after 100 ignition cycles with no current codes active during the 100 ignition cycles.

DIAGNOSTIC AIDS
^ If the shift lock control circuit is shorted to battery positive voltage, the A/T shift lock solenoid will be inoperative. The vehicle will shift out of park without depressing the brake pedal.
^ Perform the tests while wiggling the wires and connectors. This may often cause an intermittent malfunction to appear.

TEST DESCRIPTION
The number(s) below refer to the step number(s) on the diagnostic table.
2. Listen for an audible click when the A/T shift lock solenoid operates. Command both the ON and OFF states. Repeat the commands as necessary.
3. Tests for voltage at the coil side of the A/T shift lock solenoid. The ERLS fuse supplies power to the coil side of the A/T shift lock solenoid.
4. Verifies that the body control module is providing ground to the A/T shift lock solenoid.
5. Tests if ground is constantly being applied to the A/T shift lock solenoid.