Circuit/System Testing

IMPORTANT: When removing connectors, inspect for damage or corrosion. Damage or corrosion in the following requires repair or replacement of the affected component/connector:

The front end sensor
The SDM module
The front end sensor wiring harness connector
The SDM wiring harness connector

Ignition OFF, disconnect the front end sensor harness connector. Refer to front end sensor replacement for location of connector.
Remove the SDM harness connector. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement for location of connector.
Test for infinite resistance between the front end sensor signal circuit terminal 1 and ground.
- If less than infinite resistance, test the circuit for a short to ground.
Ignition ON, test for less than 1 volt between the front end 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 end 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 signal circuit front end sensor harness connector terminal 1 and SDM harness connector.
- If greater than the specified range, test the circuit for an open/high resistance.
Test for less then 1 ohm between the low reference circuit front end sensor harness connector terminal 2 and SDM harness connector terminal.
- If greater than the specified range, test the circuit for an open/high resistance.
If the circuits test normal, replace the appropriate front end sensor.
Reconnect all SIR components. Ignition ON, with a scan tool clear and recheck for DTCs.
- If the front end sensor DTC returns and is current, replace the SDM.