TR Sensor and PCM Interface

The TR sensor is a linear potentiometer device that provides the PCM with a percentage of input voltage proportional to the rotational angle of the sensor shaft. The TR sensor consists of:

• two independent signals (TR-A1 and TR-A2)
• two 5 volt reference lines (TR-VREF1 and TR-VREF2)
• two signal return lines (TR-RTN1 and TR-RTN2)

The TR-A1 signal has a positive voltage slope, meaning the voltage increases when the sensor angle increases. The typical TR voltage ranges from approximately 0.7 volt in the PARK position to approximately 3.8 volts in the LOW gear position. The TR-A2 signal has a negative voltage slope. Voltage decreases as the sensor angle increases. The typical voltage for the TR-A2 is approximately 4.3 volts in the PARK position to approximately 1.2 volts in the LOW gear position.

The TR-VREF circuits are bussed together internal to the TR sensor, and both TR-RTN circuits are bussed together internal to the TR sensor. One of the TR-VREF and one of the TR-RTN circuits are dedicated signals from the PCM. This design of redundant signals protects against an open circuit condition.