Circuit/System Testing

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

Ignition OFF, disconnect the inline harness connector listed below:
- M29L headlamp leveling actuator-left inline harness connector X111
- M29R headlamp leveling actuator-right inline harness connector X112
Test for less than 30 Ω between the ground circuit terminal A and ground.
- If greater than the specified range, test the ground circuit for an open/high resistance.
Engine running, test for less than 30 Ω between the ground circuit terminal E and ground.
- If greater than the specified range, test the ground circuit for an open/high resistance. If the circuit tests normal, replace the K28 headlamp leveling control module.
Verify that a test lamp illuminates between the control circuit terminal D and ground.
- If the test lamp does not illuminate, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K28 headlamp leveling control module.
Test for 4.25 V-5.25 V between the signal circuit terminal M and ground.
- If less than the specified range, test the signal circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the K28 headlamp leveling control module.
- If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K28 headlamp leveling control module.
If all circuits test normal, test or replace the M29 headlamp leveling actuator