Circuit/System Testing

WARNING: This page is about a different car, the 2011 GMC Acadia, 2011 Chevrolet Traverse, and 2011 Buick Enclave. However, it is still accessible from the selected car via links, so may be relevant.

Ignition OFF, disconnect the harness connector at the B71L liftgate object sensor - left.
Test for less than 10 Ω between the low reference circuit terminal A and ground.
- If greater than the specified range, test the low reference circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K39 liftgate module.
Disconnect the harness connector at the B71R liftgate object sensor - right.
Ignition ON, test for 4.75-5.25 V between the signal circuit terminal B and ground.
- If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K39 liftgate module.
- If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K39 liftgate module.
Test of infinite resistance between the signal circuit terminal A and ground.
- If not the specified value, test the signal circuit for a short to ground.
Test for less than 10 Ω between the signal circuit terminal A at the B71R liftgate object sensor - right and the signal circuit terminal B at the B71L liftgate object sensor - left.
- If greater than the specified range, test the signal circuit for an open/high resistance.
If all circuits test normal, test or replace the appropriate B71 liftgate object sensor.