Hood: Testing and Inspection
Hood Ajar Indicator/Message Malfunction
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provides an overview of each diagnostic category.
Diagnostic Fault Information
Circuit/System Description
The body control module applies B+ to the hood ajar signal circuit and monitors the voltage to determine the position of the hood. When the hood is closed, the switch is open and voltage remains high. When the hood is open, the switch is closed and the voltage is pulled low.
Reference Information
Schematic Reference
Immobilizer Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
Keyless Entry System Description and Operation (without BTM) Keyless Entry System Description and Operation (with BTM)
Electrical Information Reference
* Circuit Testing
* Connector Repairs
* Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
1. Ignition ON.
2. Observe the scan tool body control module Hood Ajar Switch parameter. With the hood open, the Hood Ajar Switch parameter should be Open. With the hood closed, the Hood Ajar Switch parameter should be Closed.
• If the parameter does not change
Refer to Circuit/System Testing.
• If the parameter changes
3. All OK.
Circuit/System Testing
1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the B55 hood ajar switch. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 10 ohms between the ground circuit terminal C and ground.
• If 10 ohms or greater
1. Ignition OFF
2. Test for less than 2 ohms in the ground circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, repair the open/high resistance in the ground connection.
• If less than 10 ohms
3. Ignition ON.
4. Test for greater than 11.5 V between the signal circuit terminal B and ground.
• If less than 11.5 V
1. Ignition OFF, disconnect the harness connector at the K9 body control module.
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.
3. Test for less than 2 ohms in the B+ circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K9 body control module.
• If greater than 11.5 V
5. Ignition OFF, disconnect the X4 and X7 harness connector at the K9 body control module. Ignition ON.
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 hood ajar switch.
Component Testing
1. Ignition OFF, disconnect the harness connector at the B55 hood ajar switch.
2. Test for 2738-3350 ohms between the signal terminal A and the signal terminal B with the hood latch in the CLOSED position.
• If not between 2738-3350 ohms
Replace the B55 hood ajar switch.
• If between 2738-3350 ohms
3. Test for 658-806 ohms between the signal terminal A and the ground terminal C with the hood latch in the CLOSED position.
• If not between 658-806 ohms
Replace the B55 hood ajar switch.
• If between 658-806 ohms
4. Test for 2080-2545 ohms between the signal terminal B and the ground terminal C with the hood latch in the CLOSED position.
• If not between 2080-2545 ohms
Replace the B55 hood ajar switch.
• If between 2080-2545 ohms
5. Test for 2738-3350 ohms between the signal terminal A and the signal terminal B with the hood latch in the OPEN position.
• If not between 2738-3350 ohms
Replace the B55 hood ajar switch.
• If between 2738-3350 ohms
6. Test for 2080-2545 ohms between the signal terminal A and the ground terminal C with the hood latch in the OPEN position.
• If not between 2080-2545 ohms
Replace the B55 hood ajar switch.
• If between 2080-2545 ohms
7. Test for 658-806 ohms between the signal terminal B and the ground terminal C with the hood latch in the OPEN position.
• If not between 658-806 ohms
Replace the B55 hood ajar switch.
• If between 658-806 ohms
8. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
* CELL Link Error - Link target cell (cell ID 9383) is invalid for this publication.
* Control Module References for body control module replacement, programming, and setup