B2708
B2708 - Gearshift Unlock Circuit HighSchematic:
CIRCUIT DESCRIPTION
The brake transmission shift interlock (BTSI) solenoid is energized by the body control module (BCM) switching circuit 816 to ground while ignition is in RUN. When energized, the BTSI solenoid will allow shifting from PARK. A condition for shifting from PARK is the foot brake must be applied. The BCM receives this information over the serial data link from the engine controller. The BTSI solenoid will allow shifting from PARK when ignition is in the ACC position without a brake pedal input.
The BCM also monitors ignition 1 circuit 339 and ignition 2 circuit 743 to determine if the ignition switch is in the RUN or ACC position.
DTC SET CONDITIONS
^ Foot brake is applied (output is On)
^ Ignition in RUN or ACC position
^ Circuit 816 is shorted to battery voltage
^ Security light, service (wrench) light, and MIL light are always On with ignition Off
^ Allows you to shift out of PARK without applying the brake pedal
DIAGNOSTIC AIDS
^ Inspect wiring harness for damage. Check for broken or chaffed insulation.
^ If fault is suspected to be intermittent, wiggling harness wiring may help in locating fault.
^ Check for poor connection at the BCM. Inspect harness connectors for backed out terminals, improper terminal mating, broken connector locks, improperly formed or damaged terminals and poor terminal to wire connection (terminal crimped over wire insulation and not conductors).
TEST
Diagnostic Chart:
