Transmission Range Sensor - Chrysler 300M Service Manual

21 - 150 TRANSAXLE
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
assembly. The electrical connector extends through
the transaxle case (Fig. 402).
Fig. 402 Valve Body Assembly
1 - SOLENOID/PRESSURE SWITCH ASSEMBLY
2 - TRS
3 - TRANSFER PLATE
4 - SEPARATOR PLATE
5 - VALVE BODY
The Transmission Range Sensor (TRS) has four
switch contacts that monitor shift lever position and
send the information to the PCM.
The TRS also has an integrated temperature sen-
sor (thermistor) that communicates transaxle tem-
perature to the PCM (Fig. 403).
OPERATION
The Transmission Range Sensor (TRS) (Fig. 402)
communicates shift lever position (SLP) to the PCM
as a combination of open and closed switches. Each
shift lever position has an assigned combination of
switch states (open/closed) that the PCM receives
from four sense circuits. The PCM interprets this
information and determines the appropriate trans-
axle gear position and shift schedule.
Since there are four switches, there are 16 possible
combinations of open and closed switches (codes).
Seven of these codes are related to gear position and
Fig. 403 Transmission Temperature Sensor

1 - TRANSMISSION RANGE SENSOR

2 - TEMPERATURE SENSOR
three are recognized as "between gear" codes. This
results in six codes which should never occur. These
are called "invalid" codes. An invalid code will result
in a DTC, and the PCM will then determine the shift
lever position based on pressure switch data. This
allows reasonably normal transmission operation
with a TRS failure.
TRS SWITCH STATES
SLP T42
P CL
R CL
N CL
OD OP
3 (AS) OP
L CL
TRANSMISSION TEMPERATURE SENSOR
The TRS has an integrated thermistor (Fig. 403)
that the PCM uses to monitor the transmission's
sump temperature. Since fluid temperature can
affect transmission shift quality and convertor lock
up, the PCM requires this information to determine
which shift schedule to operate in. The PCM also
monitors this temperature data so it can energize the
vehicle cooling fan(s) when a transmission "overheat"
condition exists. If the thermistor circuit fails, the
PCM will revert to calculated oil temperature usage.
T41 T3
CL CL OP
OP OP OP
CL OP CL
OP OP CL
OP CL OP
OP CL CL
LH
T1