Transmission Range Sensor (A/T)
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. See Figure . The electrical connector extends through the transaxle case. The TRS has 4 switch contacts that monitor shift lever position and send the information to the Transmission Control Module (TCM). The TRS also has an integrated temperature sensor (thermistor) that communicates transaxle temperature to the TCM and powertrain control module. See Fig 1 . The TRS communicates Shift Lever Position (SLP) to the TCM as a combination of open and closed switches. Each shift lever position has an assigned combination of switch states (open/closed) that the TCM receives from 4 sense circuits. The TCM interprets this information and determines the appropriate transaxle gear position and shift schedule. Since there are 4 switches, there are 16 possible combinations of open and closed switches (codes). Seven of these codes are related to gear position and 3 are recognized as between gear codes. This results in 6 codes which should never occur. These are called invalid codes. An invalid code will result in a DTC, and the TCM will then determine the shift lever position based on pressure switch data. This allows reasonably normal transmission operation with a TRS failure.