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 four switch contacts that monitor shift lever position and send the information to the Powertrain Control Module (PCM). The TRS also has an integrated temperature sensor (thermistor) that communicates transaxle temperature to the PCM. See Fig 1 . The TRS 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 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 will then determine the shift lever position based on pressure switch data. This allows reasonably normal transmission operation with a TRS failure.