The starter/generator control module (SGCM) monitors the voltage input of the hood open switch signal circuit and the hood open closed switch signal circuit. With the hood open, the hood ajar portion of the switch is closed, grounding the hood ajar switch signal circuit from the ECM, and the hood closed portion of the switch is open. With the hood closed, the hood closed portion of the switch is closed, grounding the hood closed switch signal circuit from the SGCM, and the hood ajar portion of the switch is open. During proper operation, the two separate voltage signals at the SGCM should never be at the same voltage.

The hood ajar switch status is also sent to the engine control module (ECM) via serial data.

The SGCM continuously monitors for this DTC

Both the hood open switch signal circuit and the hood closed switch signal circuit are simultaneously in an active or inactive state.

Auto-start and auto-stop operation will be disabled.

Schematic Reference

Immobilizer Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Keyless Entry System Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, observe the scan tool SGCM Hood Position parameter. With the hood open, the Hood Position parameter should read Open. With the hood closed, the Hood Position parameter should read Closed.

1. Ignition OFF, disconnect the harness connector at the hood ajar switch.
2. Ignition OFF, test for less than 10 ohms between the ground circuit terminal A and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON, test for 10.0-12.5 volts between the signal circuit terminal B and ground.

⇒	If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the SGCM.

⇒	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 SGCM.

4. Ignition ON, test for 10.0-12.5 volts between the signal circuit terminal C and ground.

⇒	If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the SGCM.

⇒	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 SGCM.

5. Ignition OFF, disconnect the harness connector at the hood ajar switch.
6. Ignition ON, observe the scan tool SGCM Hood Position parameter. With the hood open, the Hood Position parameter should read Open. With the hood closed, the Hood Position parameter should read Closed.

⇒	If the parameter does not change between the specified values, test or replace the hood ajar switch.

7. Observe the scan tool ECM Hood Position parameter. With the hood open, the Hood Position parameter should read Open. With the hood closed, the Hood Position parameter should read Closed.

⇒	If the parameter does not change between the specified values, replace the ECM.

Hood Ajar Switch

1. Ignition OFF, disconnect the harness connector at the hood ajar switch.
2. With the switch in the hood closed position, test for infinite resistance between the ground terminal A and the signal terminal C.

⇒	If not the specified value, replace the hood ajar switch.

3. Test for less than 2.0 ohms between the ground terminal A and the signal terminal B.

⇒	If greater than the specified range, replace the hood ajar switch.

4. With the switch in the hood open position, test for infinite resistance between the ground terminal C and the signal terminal B.

⇒	If not the specified value, replace the hood ajar switch.

5. Test for less than 2.0 ohms between the ground terminal C and the signal terminal A.

⇒	If greater than the specified range, replace the hood ajar switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.