<H1>Automatic Transmission Shift Lock Control Description and Operation</H1>
<H5>Automatic Transmission Shift Lock Control System</A></H5>
The automatic transmission shift lock control is a safety device that
prevents an inadvertent shift out of PARK when the ignition is ON. The driver
must press the brake pedal before moving the shift lever out of the PARK
position. The system consists of the following components:</P>
<UL type=BULLET>
<LI>The automatic transmission shift lock control solenoid.
<LI>The automatic transmission shift lock control switch.
<LI>The park/neutral position switch. </LI>[/list]
With the ignition in the ON position, battery positive voltage is supplied to
the park/neutral position switch. When the transmission is in the PARK position
the contacts in the park/neutral position switch are closed. This allows current
to flow through the switch 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 automatic transmission
shift lock control solenoid is permanently grounded. This energizes the
automatic transmission shift lock control solenoid, locking the shift linkage in
the PARK position. When the driver presses the brake pedal the contacts in the
automatic transmission shift lock control switch open, causing the automatic
transmission shift lock control solenoid to release. This allows the shift lever
to move from the PARK position.</P>
<H5>Park Lock Solenoid</A></H5>
The park lock solenoid is a safety device that prevents an inadvertent shift
out of PARK when the key is in the OFF position. The key must be in the RUN
position to release the park lock solenoid. The system consists of the park lock
solenoid. With the ignition in the ON position, voltage is supplied to the park
lock solenoid. The park lock solenoid energizes through a permanent ground
unlocking the shift lever. With the ignition in the OFF or ACCY position the
park lock solenoid de-energizes and locks the shift lever in the park
position.</P>