Automatic Transmission Shift Lock Control System
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. The system consists of the following components:
• | The automatic transmission shift lock control solenoid |
• | The automatic transmission shift lock control switch |
• | The body control module (BCM) |
• | The powertrain control module (PCM) |
With the ignition in the ON position, battery positive voltage is supplied
to the automatic transmission shift lock control switch. The circuit continues
through the normally-closed switch to the automatic transmission shift
lock control solenoid. The BCM provides a ground for the automatic
transmission shift lock control solenoid when the transmission is in the
PARK position. The BCM receives the transmission gear position information
via class2 serial data from the PCM. This causes the automatic transmission
shift lock control solenoid to energize and lock 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. This causes
the automatic transmission shift lock control solenoid to release. This
allows the shift lever to move from the PARK position. The BCM turns
off the automatic transmission shift lock control solenoid ground circuit
when the transmission is out of the PARK position.