B1820-HOOD AJAR INPUT CIRCUIT HIGH

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

When Monitored:
Continuously
Set Condition:
When the Totally Integrated Power Module senses 12 volts on the Hood Ajar Switch Sense circuit for over 10 seconds, this code will set.

Possible Causes
(G931) SENSOR GROUND CIRCUIT OPEN
(G70) HOOD AJAR SWITCH SENSE CIRCUIT SHORT TO VOLTAGE
(G70) HOOD AJAR SWITCH SENSE CIRCUIT OPEN
HOOD AJAR SWITCH OPEN
TOTALLY INTEGRATED POWER MODULE (TIPM)

1. TEST FOR INTERMITTENT CONDITION

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

1.	With 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.	With the scan tool, read DTCs.

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

Yes

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. (Refer to 28 - DTC-Based Diagnostics/MODULE, Totally Integrated Power (TIPM) - Standard Procedure).

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

3. HOOD AJAR SWITCH OPEN

1.	Disconnect the Hood Ajar Switch harness connector.

2.	Depress the plunger of the hood ajar switch and measure the resistance between the two terminals of the switch.

Is the resistance approximately 1k Ohms?

Yes

4. (G931) SENSOR GROUND CIRCUIT OPEN

1.	Using a 12-volt Test Light connected to 12-volts, check the (G931) Sensor Ground circuit.

Does the test light illuminate?

Yes

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

1.	Disconnect the TIPM C4 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. (Refer to 28 - DTC-Based Diagnostics/MODULE, Totally Integrated Power (TIPM) - Standard Procedure).

6. (G70) HOOD AJAR SWITCH SENSE CIRCUIT OPEN

1.	Turn the ignition off.

2.	Measure the resistance of the (G70) Hood Ajar Switch Sense circuit between the TIPM C4 connector and the Hood Ajar Switch connector.

Is the resistance below 2.0 Ohms?

Yes

Replace the Totally Integrated Power Module (TIPM) in accordance with the service information.
Perform the BODY VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Totally Integrated Power (TIPM) - Standard Procedure).

Repair the (G70) Hood Ajar Switch Sense circuit for an open.
Perform the BODY VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Totally Integrated Power (TIPM) - Standard Procedure).