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Pinpoint Test B: The Alarm System Does Not Activate From An Unauthorized Entry At The Hood




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Pinpoint Tests

Pinpoint Test B: The Alarm System Does Not Activate From An Unauthorized Entry At The Hood

Refer to Wiring Diagram Set 117, Remote Keyless Entry and Alarm for schematic and connector information. Diagrams By Number

Normal Operation

When the alarm system is armed, the Smart Junction Box (SJB) monitors the hood ajar switch. If the hood is opened while the alarm is armed, the hood ajar switch removes ground from the signal circuit. This signals the SJB that an unauthorized intrusion to the engine compartment has occurred and the SJB activates the alarm.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors
- Hood switch
- SJB

PINPOINT TEST B: THE ALARM SYSTEM DOES NOT ACTIVATE FROM AN UNAUTHORIZED ENTRY AT THE HOOD

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

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B1 RETRIEVE THE RECORDED DTCs IN THE SJB


NOTE: DTC B1520 sets if the hood is open. Make sure the hood is closed prior to running the self-test.

- Retrieve the recorded DTCs from the SJB self-test.
- Is DTC B1520 present?

Yes
GO to Pinpoint Test C. Pinpoint Test C: DTC B1520

No
GO to B2.

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B2 CHECK THE HOOD SWITCH


- Ignition OFF.
- Disconnect: Hood Switch C127.
- Monitor the SJB PID (HOOD_SW) while disconnecting the hood switch.
- Does the SJB PID read AJAR when the switch is disconnected?

Yes
INSTALL a new hood switch. TEST the system for normal operation.

No
GO to B3.

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B3 CHECK THE HOOD SWITCH SENSE CIRCUIT FOR A SHORT TO GROUND


- Disconnect: SJB C2280F.
- Measure the resistance between the hood switch C127-1, circuit CPL25 (BU/OG), harness side and ground.




- Is the resistance greater than 10,000 ohms?

Yes
GO to B4.

No
REPAIR the circuit. TEST the system for normal operation.

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B4 CHECK FOR CORRECT SJB OPERATION


- Disconnect all the SJB connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the SJB connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?

Yes
INSTALL a new SJB. REFER to Multifunction Electronic Modules Service and Repair. TEST the system for normal operation.

No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.

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