B1820

B1820-HOOD AJAR INPUT CIRCUIT HIGH





For a complete wiring diagram, refer to the Wiring Information.

- When Monitored:
Continuously

- Set Condition:
When the FCM senses 12 Volts on the Hood Ajar Switch Sense circuit for over 10 seconds, this code will set.





1. TEST FOR INTERMITTENT CONDITION

NOTE: Open the hood and ensure the Hood Ajar Switch is connected before proceeding

1. Using the scan tool, record and erase DTCs
2. Close the hood.
3. Cycle the ignition from on to off.
4. Turn the ignition on.
5. Open then close the hood.
6. Using the scan tool, read DTCs.

Does the scan tool display B1820-HOOD AJAR INPUT CIRCUIT HIGH?

Yes

- Go To 2

No

- The conditions that caused this code to set are not present at this time. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

2. INCORRECT HOOD AJAR SWITCH INSTALLED
1. Inspect the retainer ring on the hood ajar switch.
2. 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 3

No

- Replace the Hood Ajar Switch.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

3. HOOD AJAR SWITCH OPEN
1. Turn the ignition off.
2. Disconnect the Hood Ajar Switch harness connector.
3. Depress the plunger of the Hood Ajar Switch.
4. Measure the resistance between the two terminals of the Hood Ajar Switch.

Is the resistance approximately 1000 Ohms?

Yes

- Go To 4

No

- Replace the Hood Ajar Switch.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

4. (Z384) GROUND CIRCUIT OPEN




1. Using a 12-volt Test Light connected to 12-volts, check the (Z384) Ground circuit.

Does the test light illuminate?

Yes

- Go To 5

No

- Repair the (Z384) Ground circuit for an open.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

5. (G70) HOOD AJAR SWITCH SENSE CIRCUIT SHORT TO VOLTAGE




1. Disconnect the Front Control Module 49-way connector.
2. Turn the ignition on.
3. 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. Body Verification Test.

No

- Go To 6

6. (G70) HOOD AJAR SWITCH SENSE CIRCUIT OPEN




1. Turn the ignition off.
2. Disconnect the Integrated Power Module C2 40-way connector.
3. 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 7

No

- Repair the (G70) Hood Ajar Switch Sense circuit for an open.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

7. (G70) IPM HOOD AJAR SWITCH SENSE CIRCUIT OPEN





NOTE: Use the graphic connector pinout as a reference to check the Integrated Power Module.

1. 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).
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Replace the Integrated Power Module (IPM).
- Perform the BODY VERIFICATION TEST. Body Verification Test.