B1820

B1820 - Hood Ajar Input Circuit High






For a complete wiring diagram, refer to

• When Monitored: Continuously.

• Set Condition: When the totally integrated power module senses the hood ajar switch sense circuit is open.






Test Step 1 - Test For Intermittent Condition

• Open the hood and ensure the hood ajar switch is connected before proceeding.

• With 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.

• With the scan tool, read DTCs.

Does the scan tool display B1820 - Hood Ajar Input Circuit High?

Yes

• Go to Test Step 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. Refer to => Non-DTC Based Diagnostics. Body Interior

Test Step 2 - Hood Ajar Switch Open

• Disconnect the hood ajar switch harness connector.

• 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

• Go to Test Step 3.

No

• Replace the hood ajar switch.

• Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior

Test Step 3 - Sensor Ground Circuit Open







• Using a test lamp connected to 12 volts, test the sensor ground circuit.

Does the Test lamp illuminate?

Yes

• Go to Test Step 4.

No

• Repair the circuit for an open.

• Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior

Test Step 4 - Hood Ajar Switch Sense Circuit Short to Voltage







• Disconnect the TIPM connector.

• Turn the ignition ON.

• Measure the voltage between the hood ajar switch sense circuit and ground.

Is there any voltage present?

Yes

• Repair the circuit for a short to voltage.

• Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior

No

• Go to Test Step 5.

Test Step 5 - Hood Ajar Switch Sense Circuit Open







• Turn the ignition OFF.

• Measure the resistance of the hood ajar switch sense circuit between the TIPM connector and the hood ajar switch connector.

Is the resistance less than 2.0 ohms?

Yes

• Replace the TIPM..

• Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior

No

• Repair the circuit for an open.

• Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior