Transmission Position Sensor/Switch: Testing and Inspection

Transmission Range (TR) Sensor Testing Using
Transmission Tester
The transmission tester allows a technician to operate the electrical portion of the TR sensor.
1. Perform Preparation and Hook-up procedures.

Caution: For resistance checks, be sure that the tester selector switch is set to the TR SENSOR TEST position or damage to the ohmmeter may result.

2. Resistance/continuity tests.
- Using a digital volt-ohmmeter, the transmission tester and Transmission Range (TR) Sensor Cable 49 UNO1 147 or equivalent, perform TR Sensor test based on the DTCs that were displayed.
- Perform services as indicated by the pinpoint tests. Always retest and road test vehicle after any service.




3. TR sensor resistance tests.
- Set ohmmeter to 1000 ohm range.
- Connect the positive lead of the ohmmeter to the TR/MLP jack.
- Connect the negative lead of the ohmmeter to the SIG RTN jack.
- Move transmission gearshift selector lever into each gear position.
- Record resistance at each position.
- Refer to the following chart for values.
- If out of range, perform TR Sensor test.
4. Voltage tests-park/neutral, backup lamp and optional circuit.
- Set tester selector switch to the TR SENSOR TEST position.
- Press and HOLD each button while moving the gear-shift lever through EACH gear position.
- Monitor each LED.
- The status LED should indicate RED only in the indicated position. Refer to overlay.

Note: LED will turn RED when the circuit closes and turn OFF when the circuit is open.

- If the LED does NOT indicate RED in the desired position or indicates RED in another position, first verify Transmission Range (TR) sensor alignment and then retest. If the sensor fails, replace.
5. Perform tester removal.