Chrysler Dodge Caravan 2002 Manual page 1833

21 - 276 41TE AUTOMATIC TRANSAXLE
SHIFT INTERLOCK SOLENOID (Continued)
OPERATION
The Brake/Transmission Shift Interlock (BTSI)
Solenoid prevents the transmission shift lever from
being moved out of PARK (P) unless the brake pedal
is applied. The BTSI solenoid is hardwired to and
controlled by the Intelligent Power Module (IPM).
Battery voltage is applied to one side of the solenoid
with the ignition key is in either the OFF, ON/RUN,
or START positions (Fig. 302). The ground side of the
solenoid is controlled by a driver within the IPM. It
relies on voltage supplied from the stop lamp switch
to the stop lamp sense circuit within the IPM to tell
when the brake pedal is depressed. When the brake
pedal is depressed, the ground circuit opens, de-ener-
gizing the solenoid. When the brake pedal is
released, the ground circuit is closed, energizing the
solenoid.
Fig. 302 Ignition Key/Switch Positions
1 - ACC
2 - LOCK
3 - OFF
4 - ON/RUN
5 - START
When the ignition key is in either the OFF,
ON/RUN, or START positions, the BTSI solenoid is
energized, and the solenoid plunger hook pulls the
shift lever pawl into position, prohibiting the shift
lever from moving out of PARK (P) (Fig. 303). When
the brake pedal is depressed, the ground circuit
opens, de-energizing the solenoid. This moves the
gearshift lever pawl out of the way (Fig. 304), allow-
ing the shift lever to be moved into any gear position.
Fig. 303 Pawl Engaged to Shift Lever
1 - GEAR SHIFT LEVER
2 - GEAR SHIFT LEVER PAWL
Fig. 304 Pawl Disengaged From Shift Lever
1 - GEAR SHIFT LEVER
2 - GEAR SHIFT LEVER PAWL
RS