Circuit/System Testing

WARNING: This page is about a different car, the 2008 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.

Ignition OFF, disconnect the harness connector of the suspect rear object alarm sensor.
Test for less than 1.0 ohm of resistance between the low reference circuit terminal 2 and ground.
- If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the rear object alarm module.
Ignition ON, with the transmission in reverse, test for 8.2-8.8 volts between the rear object alarm sensor supply voltage circuit terminal 1 and the low reference circuit terminal 2.
- If greater than the specified range, test the supply voltage circuit for a short to voltage. If the circuit tests normal, replace the object alarm module.
- If less than the specified range, test the supply voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the rear object alarm module.
Test for 7.2-9.2 volts between the rear object alarm sensor signal circuit terminal 3 and the low reference circuit terminal 2.
- If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the rear object alarm module.
- 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 rear object alarm module.
If all circuits test normal, replace the suspect rear object alarm sensor.