The automatic transmission shift lock control system is a safety device
that prevents an inadvertent shift out of PARK when the engine is running.
The driver must press the brake pedal before moving the shift lever
out of the PARK position.
Column Shift
The column shift system consists of the following components:
• | The automatic transmission shift lock solenoid |
• | The automatic transmission shift lock control switch |
• | The rear integration module (RIM) |
• | The powertrain control module (PCM) |
With the ignition ON, positive voltage is supplied from the ignition
switch to the coil side feed circuit of the park relay. The RIM receives
a gear position input signal from the PCM through a class 2 serial
data message. When the RIM receives a PARK position message from the
PCM, the RIM applies a ground to the control circuit of the park relay.
This energizes the relay, closing the switch contracts in the relay.
Battery voltage flows through the relay to the automatic transmission
shift lock control switch. With the brake pedal released, voltage flows
through the normally closed contacts of the automatic transmission
shift lock control switch to the automatic transmission shift lock
control solenoid. The automatic transmission shift lock control solenoid
is permanently grounded. This energizes the automatic transmission shift
lock control solenoid, mechanically locking the shift lever in the PARK
position. When the driver presses the brake pedal, the contacts of
the automatic transmission shift lock control switch open, de-energizing
the automatic transmission shift lock control solenoid. This allows the
shift lever to be moved out of the PARK position.
When the shift lever is moved out of the PARK position , the PCM sends
a class 2 serial data message to the RIM. The RIM then opens the ground
path of the park relay control circuit , de-energizing the park relay
and disabling the automatic transmission shift lock control solenoid.
Once the vehicle is out of PARK, the automatic transmission shift
lock control solenoid remains de-energized until the RIM receives a
PARK signal from the PCM.
Console Shift
The console shift system consists of the following components:
• | The automatic transmission shift lock control switch |
• | The automatic transmission shift lock control solenoid |
• | The automatic transmission shift lock control relay |
• | The rear integration module (RIM) |
• | The powertrain control module (PCM) |
With the ignition ON, battery voltage is supplied to the coil side feed
circuit of the brake to shift relay. When the RIM receives a PARK signal
though a class 2 serial data message from the PCM the RIM grounds
the control circuit of the brake to shift relay. This energizes the
brake to shift relay coil and closes the switch contacts in the relay.
Battery voltages flows through the switch side of the park relay to
the automatic transmission shift lock control switch. The contacts in the
automatic transmission shift lock control switch are normally closed
allowing voltage to flow to the coil side of the shift lock relay. The
coil side of the shift lock relay is permanently grounded. This energizes
the shift lock relay, opening the normally closed switch side contacts.
With the switch contacts open the automatic transmission shift lock control
solenoid de-energizes, locking the shift lever in the PARK position.
When the driver presses the brake pedal the contacts in the automatic
transmission shift lock control switch open, de-energizing the shift lock
relay. The switch side contacts close and voltage form the ignition 3
relay flows through the shift lock relay contacts to the permanently
ground automatic transmission shift lock control solenoid. The solenoid
energizes and unlocks the shift lever, allowing the driver to move the
shift lever out of the PARK position.
When the shift lever is moved out of the PARK position , the PCM sends
a class 2 serial data message to the RIM. The RIM then opens the ground
path of the park relay control circuit , de-energizing the park relay
and the shift lock relay. Once the vehicle is out of PARK, the automatic
transmission shift lock control solenoid remains energized or unlocked
until the RIM receives a PARK signal from the PCM.
Shift Lock Bypass Procedure
In the event that service is required, a park lock solenoid manual release
lever is located on the right side of the floor shift assembly. To operate
the manual release, block the wheels and apply the parking brake. Remove
the shift lever trim panel and depress the release lever, move the shift lever
to the NEUTRAL position while the lever is depressed.