position. The system consists of the following components:
z
The automatic transmission shift lock control solenoid.
z
The automatic transmission shift lock control switch.
z
The park/neutral position switch.
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.
Park Lock Solenoid
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.
2004 Hummer H2
2004 TRANSMISSION Shift Lock Control - Hummer H2