Diagnostic Test
- TEST FOR INTERMITTENT CONDITION NOTE: Open the hood and ensure the Hood Ajar Switch is connected before proceeding
- Using the scan tool, record and erase DTCs
- Close the hood.
- Cycle the ignition from on to off.
- Turn the ignition on.
- Open then close the hood.
- Using the scan tool, read DTCs.
Does the scan tool display B1820-HOOD AJAR INPUT CIRCUIT HIGH?
Yes
- Go to step 2
No
- The conditions that caused this code to set are not present at this time. Using the SYSTEM WIRING DIAGRAMS as a guide, inspect the wiring and connectors.
- Perform the BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
- INCORRECT HOOD AJAR SWITCH INSTALLED
- Inspect the retainer ring on the hood ajar switch.
- A dark brown retainer ring identifies the hood ajar switch used for certain export applications, while a white retainer ring identifies the remote starter system application.
Is the correct switch installed?
Yes
- Go to step 3
No
- Replace the Hood Ajar Switch.
- Perform the BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
- HOOD AJAR SWITCH OPEN
- Disconnect the Hood Ajar Switch harness connector.
- Measure the resistance between the two terminals of the Hood Ajar Switch
Is the resistance approximately 1000 Ohms?
Yes
- Go to step 4
No
- Replace the Hood Ajar Switch.
- Perform the BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
- (Z384) GROUND CIRCUIT OPEN
- Using a 12-volt Test Light connected to 12-volts, check the (Z384) Ground circuit.
Does the test light illuminate?
Yes
- Go to step 5
No
- Repair the (Z384) Ground circuit for an open.
- Perform the BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
- Using a 12-volt Test Light connected to 12-volts, check the (Z384) Ground circuit.
- (G70) HOOD AJAR SWITCH SENSE CIRCUIT SHORT TO VOLTAGE
- Disconnect the Front Control Module 49-way connector.
- Turn the ignition on.
- Measure the voltage between the (G70) Hood Ajar Switch Sense circuit and ground.
Is there any voltage present?
Yes
- Repair the (G70) Hood Ajar Switch Sense circuit for a short to voltage.
- Perform the BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
No
- Go to step 6
- (G70) HOOD AJAR SWITCH SENSE CIRCUIT OPEN
- Turn the ignition off.
- Disconnect the Integrated Power Module C2 40-way connector.
- Measure the resistance of the (G70) Hood Ajar Switch Sense circuit between the IPM connector and the Hood Ajar Switch connector.
Is the resistance below 2.0 Ohms?
Yes
- Go to step 7
No
- Repair the (G70) Hood Ajar Switch Sense circuit for an open.
- Perform the BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
- (G70) IPM HOOD AJAR SWITCH SENSE CIRCUIT OPEN
NOTE: Use the graphic connector pinout as a reference to check the Integrated Power Module.
- Measure the resistance of the (G70) Hood Ajar Switch Sense circuit between the IPM C2 40-connector and the Front Control Module 49-way connector.
Is the resistance below 1.0 Ohm?
Yes
- Replace the Front Control Module (FCM) in accordance with the Service Information.
- Perform the BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
No
- Replace the Integrated Power Module (IPM) in accordance with the Service Information.
- Perform the BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
- Measure the resistance of the (G70) Hood Ajar Switch Sense circuit between the IPM C2 40-connector and the Front Control Module 49-way connector.