Circuit/System Testing
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2012 GMC Yukon XL, 2012 GMC Yukon, 2012 Chevrolet Tahoe, 2012 Chevrolet Suburban, and 2012 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
- Front impact sensor
- SDM module
- Front impact sensor wiring harness connector
- SDM wiring harness connector
- Ignition OFF, disconnect the front impact sensor harness connector.
- Remove the SDM harness connector.
- Test for infinite resistance between the front impact sensor signal circuit terminal 1 and ground.
- If less than the specified value, test the circuit for a short to ground.
- Ignition ON, test for less than 1 volt between the front impact sensor signal circuit terminal 1 and ground.
- If greater than the specified range, test the circuit for a short to voltage.
- Ignition ON, test for less than 1 volt between the front impact sensor low reference circuit terminal 2 and ground.
- If greater than the specified range, test the circuit for a short to voltage.
- Test for less then 1 ohm between the front impact sensor signal circuit terminal 1 and the SDM terminal.
- If greater than the specified range, test the circuit for an open/high resistance.
- Test for less then 1 ohm between the front impact sensor low reference circuit terminal 2 and the SDM terminal.
- If greater than the specified range, test the circuit for an open/high resistance.
- If the circuits test normal, replace the appropriate front impact sensor.
- Reconnect all SIR components. Ignition ON, with a scan tool clear and recheck for DTCs.
- If the front impact sensor DTC returns and is current, replace the SDM.
IMPORTANT:
When removing connectors, inspect for damage or corrosion. Damage or corrosion in the following requires repair or replacement of the affected component/connector: