Circuit/System Testing

WARNING: This page is about a different car, the 2010 Cadillac STS. However, it is still accessible from the selected car via links, so may be relevant.

Ignition OFF, disconnect the harness connector at the outside moisture sensor.
Test for less than 5.0 Ω between the ground circuit terminal 3 and ground.
- If greater than the specified range, test the ground circuit for an open/high resistance.
Ignition ON, verify that a test lamp illuminates between accessory voltage circuit terminal 4 and ground.
- If the test does not illuminate, test the accessory voltage circuit for a short to ground or an open/high resistance.
Ignition ON, test for 4.0-8.5 V between signal circuit terminal 2 and ground.
- If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the outside moisture sensor.
- 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 outside moisture sensor.
Ignition OFF, reconnect the harness connector to the rain sensor.
Disconnect the (X4) harness connector at the BCM.
Ignition ON, test for 5-10 V between the signal circuit terminal 14 and ground.
- If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the outside moisture sensor.
- 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 outside moisture sensor.
If all circuits test normal, replace the BCM.