B1820–HOOD AJAR INPUT CIRCUIT HIGH

For a complete wiring diagram Refer to Section 8W

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.

Possible Causes

INCORRECT HOOD AJAR SWITCH INSTALLED

HOOD AJAR SWITCH OPEN

(Z384) GROUND CIRCUIT OPEN

(G70) HOOD AJAR SWITCH SENSE CIRCUIT SHORT TO VOLTAGE

(G70) HOOD AJAR SWITCH SENSE CIRCUIT OPEN

FRONT CONTROL MODULE (FCM)

1.TEST FOR INTERMITTENT CONDITION

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

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 BODY VERIFICATION TEST - VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE)

2.INCORRECT HOOD AJAR SWITCH INSTALLED

Is the correct switch installed?

Yes

3.HOOD AJAR SWITCH OPEN

Is the resistance approximately 1000 ohms?

Yes

4.(Z384) GROUND CIRCUIT OPEN

Does the test light illuminate?

Yes

Repair the (Z384) Ground circuit for an open.
Perform BODY VERIFICATION TEST - VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE)

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

Is there any voltage present?

Yes

Repair the (G70) Hood Ajar Switch Sense circuit for a short to voltage.
Perform BODY VERIFICATION TEST - VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE)

6.(G70) HOOD AJAR SWITCH SENSE CIRCUIT OPEN

Is the resistance below 2.0 ohms?

Yes

Repair the (G70) Hood Ajar Switch Sense circuit for an open.
Perform BODY VERIFICATION TEST - VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE)

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

Is the resistance below 1.0 ohms?

Yes

Replace the Front Control Module (FCM) in accordance with the service information.
Perform BODY VERIFICATION TEST - VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE)

Replace the Integrated Power Module (IPM) in accordance with the service information.
Perform BODY VERIFICATION TEST - VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE)