Volt

Bonnet Ajar Indicator/Message Malfunction

The body control module (BCM) applies B+ to the bonnet ajar signal circuit and monitors the voltage to determine the position of the bonnet. The bonnet ajar switch contains a multiplexed resistor. This resistor will vary the voltage seen by the BCM by pulling down the applied voltage based on the position of the switch.

Schematic Reference

Immobiliser Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Keyless Entry System Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

1. Vehicle in Service Mode.
2. Observe the scan tool Bonnet Ajar Switch parameter. With the bonnet open, the Bonnet Ajar Switch parameter should be Open. With the bonnet closed, the Bonnet Ajar Switch parameter should be Closed.

⇒	If the parameter does not change

Refer to Circuit/System Testing.

⇓	If the parameter changes

3. All OK.

1. Vehicle OFF and all vehicle systems OFF, disconnect the harness connector at the B55 bonnet ajar switch. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 10 Ω between the ground circuit terminal C and ground.

⇒	If 10 Ω or greater

2.1.	Vehicle OFF

2.2.	Test for less than 2 Ω in the ground circuit end to end.

⇒	If 2 Ω or greater, repair the open/high resistance in the circuit.

⇒	If less than 2 Ω, repair the open/high resistance in the ground connection.

⇓	If less than 10 Ω

3. Vehicle in Service Mode.
4. Test for B+ between the signal circuit terminal B and ground.

⇒	If less than B+

4.1.	Vehicle OFF, disconnect the harness connector at the BCM.

4.2.	Test for infinite resistance between the B+ circuit and ground.

⇒	If less than infinite resistance, repair the short to ground on the circuit.

⇓	If Infinite resistance.

4.3.	Test for less than 2 Ω in the B+ circuit end to end.

⇒	If 2 Ω or greater, repair the open/high resistance in the circuit.

⇒	If less than 2 Ω, replace the BCM.

⇓

If B+

5. Vehicle OFF, disconnect the X4 and X7 harness connector at the K9 BCM. Vehicle in Service Mode.
6. Test for less than 1 V between the signal circuit terminal B and ground.

⇒	If 1 V or greater

Repair the short to voltage on the circuit.

⇓	If less than 1 V

7. Test or replace the B55 bonnet ajar switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.