Grand Caravan V6-3.3L VIN R (2005)
Transmission Position Switch/Sensor: Description and Operation
40TE Automatic 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. The electrical connector extends through the transaxle case (Fig. 303).
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 sensor (thermistor) that communicates transaxle temperature to the TCM and PCM (Fig. 304).
OPERATION
The Transmission Range Sensor (TRS) (Fig. 303) 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 interprets this information and determines the appropriate transaxle 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 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/TCM will then determine the shift lever position based on pressure switch data. This allows
reasonably normal transmission operation with a TRS failure.
