The Auto Trans Shift Lock Control system on vehicles equipped with the column mounted gear shifter uses the following components:

When the ignition switch is turned to ON, ignition positive voltage is supplied from the ignition switch to the coil side of the park relay in the rear fuse block. The opposite side of the coil is wired to the Rear Integration Module (RIM). The Internal Mode Switch in the transmission determines the position of the gear shifter and provides this information to the powertrain control module (PCM) via four additional circuits. When the gear shifter is in PARK, the PCM sends a Class 2 message informing the RIM of the position of the shifter. The RIM then provides a ground path for the Park Relay coil side control circuit. With the park relay thus energized, battery positive voltage is provided from the Park/Reverse fuse in the rear junction block through the switch contacts of the park relay and the normally-closed brake-pedal mounted stoplamp/auto trans shift lock control switch connector to the auto trans shift lock actuator. The auto trans shift lock actuator, which is always grounded, then energizes and physically moves a mechanical pin out to lock the gear shifter in the PARK position. Depressing the brake pedal opens the contacts of the stoplamp/auto trans shift lock control switch, removing power from the auto trans shift lock actuator. The actuator de-energizes, the mechanical pin retreats into the body of the actuator, and the driver is allowed to move the gear shifter out of PARK.

When the gear shifter moves out of PARK, the internal mode switch in the transmission signals the PCM of the change via its four input circuits, and the PCM provides this information to the RIM via Class 2 message. The RIM then opens the ground path of the park relay control circuit , thus de-energizing the park relay and disabling the auto trans shift lock actuator. Once the vehicle is out of PARK, the auto trans shift lock actuator remains de-energized when the brake pedal is released and the stoplamp/auto trans shift lock control switch contacts return to the normally-closed state.

The Auto Trans Shift Lock Control system on vehicles equipped with the console floor shifter uses the following components:

It works in a way that is similiar to the column shifter. However, the actuator for the column shifter is energized in order to mechanically lock the gear shifter, while the actuator for the console shifter is de-energized to accomplish the same thing.

When the ignition is turned ON, battery voltage is supplied to the coil side of the Park Relay. The opposite side of the park relay is wired to the Rear Integration Module (RIM). The RIM communicates via the Serial Data Class 2 line with the Powertrain Control Module (PCM), and the PCM communicates with the transmission Internal Mode Switch (IMS) via four additional circuits. When the IMS signals the PCM that the gear shifter is in PARK, the PCM sends a class 2 message to the RIM informing it of the position of the shifter. With the ignition On, and battery voltage applied to the coil side of the park relay, the RIM then provides a ground path to energize the coil side of the relay. This closes the switch side contacts of the park relay and allows battery voltage to flow through the switch side control circuit of the park relay, the normally closed contacts of the stoplamp/auto trans shift lock control switch, and the control circuit of the stoplamp/auto trans shift lock control switch, to the coil side of the shift lock relay, which is mounted internally in the auto trans shift lock control actuator assembly. The opposite side of the coil of the shift lock relay is always grounded at a ground splice pack located at the right front corner of the passenger compartment, under the sill trim plate. With battery voltage and ground thus supplied, the coil side of the shift lock relay is energized and it's switch side contacts are opened

The Ignition 3 Relay controls the battery voltage supply to the switch side of the internally mounted shift lock relay. When the ignition is turned ON, battery voltage is supplied to coil side of the the ignition 3 relay. The relay is then energized to close it's switch side contacts. With the switch side contacts closed, battery voltage flows through the ignition 3 relay and the switch side control circuit to the switch side of the shift lock relay mounted internally in the auto trans shift lock actuator assembly.

Because the switch side of the shift lock relay controls the internally mounted shift lock actuator's battery voltage supply, the actuator is de-energized and its mechanical pin is released to physically block the floor shifter from shifting the transmission out of Park. When the brake pedal is depressed, the contacts of the stoplamp/auto trans shift lock control switch are opened, which de-energizes the internally mounted shift lock relay. This, in turn, allows the switch side contacts of the internally mounted shift lock relay to close, and battery voltage is supplied by the ignition 3 relay, through the switch side actuator control circuit, and the now closed contacts of the internally mounted shift lock relay, to the actuator. With the actuator now energized, the mechanical pin is pulled to the inward position and gear shifter movement is now possible.

On vehicles equipped with the floor mounted console shifter a Reverse Lockout System is used to prevent the vehicle from being accidently shifted from a forward or neutral gear into reverse. The following components are used to control the reverse lockout function:

When the ignition switch is turned ON, battery voltage is supplied to the coil side of the reverse lockout relay. The opposite side of the reverse lockout relay coil is wired to the dash integration module (DIM). When the DIM determines that the ignition is ON and the vehicle has been traveling at over 5 mph for 15 seconds or longer, it provides a ground path for the coil side of the reverse lockout relay through the coil side control circuit of the relay. This energizes the relay to close the switch side contacts of the relay. Battery voltage that is supplied at all times through the reverse lockout fuse to the switch side of the reverse lockout relay then flows through the switch side contacts and the switch side control circuit of the relay to the reverse lockout actuator. The actuator is always grounded by the actuator ground circuit, which is wired to a splice pack located at the right front corner of the passenger compartment, under the sill trim plate. With battery voltage and ground thus supplied to the reverse lockout actuator, it becomes energized to thrust it's mechanical pin to the outward position to physically block the movement of the floor shifter to the reverse position from the neutral or forward drive gear positions.