service schedule CHRYSLER CARAVAN 2003 Owner's Manual

OPERATION
The relay is supplied fused B+ voltage, energized
by the PCM/TCM, and is used to supply power to the
solenoid pack when the transmission is in normal
operating mode. When the relay is ªoffº, no power is
supplied to the solenoid pack and the transmission is
in ªlimp-inº mode. After a controller reset (ignition
key turned to the ªrunº position or after cranking
engine), the PCM/TCM energizes the relay. Prior to
this, the PCM/TCM verifies that the contacts are
open by checking for no voltage at the switched bat-
tery terminals. After this is verified, the voltage at
the solenoid pack pressure switches is checked. After
the relay is energized, the PCM/TCM monitors the
terminals to verify that the voltage is greater than 3
volts.
TRANSMISSION RANGE
SENSOR
DESCRIPTION
The Transmission Range Sensor (TRS) is mounted
to the top of the valve body inside the transaxle and
can only be serviced by removing the valve body. The
electrical connector extends through the transaxle
case (Fig. 328).
The Transmission Range Sensor (TRS) has four
switch contacts that monitor shift lever position and
send the information to the PCM/TCM.The TRS also has an integrated temperature sen-
sor (thermistor) that communicates transaxle tem-
perature to the TCM and PCM (Fig. 329).
OPERATION
The Transmission Range Sensor (TRS) (Fig. 328)
communicates shift lever position (SLP) to the PCM/
TCM as a combination of open and closed switches.
Each shift lever position has an assigned combination
of switch states (open/closed) that the PCM/TCM
receives from four sense circuits. The PCM/TCM inter-
prets this information and determines the appropriate
transaxle gear position and shift schedule.
Fig. 327 Transmission Control Relay Location
1 - TRANSMISSION CONTROL RELAY
2 - LEFT FENDER
3 - INTELLIGENT POWER MODULE (IPM)
4 - BATTERY
Fig. 328 Transmission Range Sensor (TRS)
Location
1 - TRANSMISSION RANGE SENSOR
Fig. 329 Transmission Temperature Sensor
1 - TRANSMISSION RANGE SENSOR
2 - TEMPERATURE SENSOR
21 - 248 41TE AUTOMATIC TRANSAXLERS
TRANSMISSION CONTROL RELAY (Continued)
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