Power Trunk / Liftgate Hazard Sensor: Testing and Inspection

DIAGNOSIS AND TESTING

SENSOR

WARNING: To avoid serious or fatal injury during testing of pinch sensor operation, use extreme caution to keep away from the closing liftgate.

To verify power liftgate system pinch sensor operation:

1. Cycle the power liftgate through two complete Open and Close cycles. During each of the Close cycles, while the liftgate is in mid-travel, depress one of the pinch sensors using a yardstick so as to keep hands from between the liftgate opening and the liftgate. The Power Liftgate Module (PLGM) (also known as the Power Liftgate/PLG control module) should halt the Close cycle and reverse the liftgate to the fully open position when a pinch sensor is depressed. Repeat the test for the second pinch sensor. If not OK, proceed to the next Step.
2. Remove the lower trim from the inside of the liftgate to access and disconnect the pinch sensor pigtail wire connectors from the liftgate wire harness. Using an ohmmeter, check the resistance between the two pins of each pinch sensor pigtail wire connector. When the sensor is depressed (contacts are closed), the resistance should be 300 ohms maximum. When the pinch sensor is released (contacts are open) the resistance should be 10,000 ohms minimum. If not OK, replace the ineffective pinch sensor.

THERMISTOR

The thermistor portion of the right pinch sensor provides a temperature sense input to the Power Liftgate Module (PLGM) (also known as the Power Liftgate/PLG control module). The temperature input is only provided when the pinch sensor is in a non-pinched (contacts are open) condition. When the pinch sensor contacts are closed (sensor is pinched) this input is unavailable because the thermistor is shorted. Remove the lower trim from the inside of the liftgate to access and disconnect the right pinch sensor pigtail wire connector from the liftgate wire harness. Refer to the Right Pinch Sensor Thermistor Resistance table and check between the two terminals of the sensor connector for the proper thermistor resistance at the listed temperatures. If the sensor fails this test, replace the right pinch sensor unit.