Pinpoint Test B: The Alarm System Does Not Operate Correctly - Alarm Does Not Activate With Hood Ajar/Open
Anti-Theft
Pinpoint Test B: The Alarm System Does Not Operate Correctly - Alarm Does Not Activate With Hood Ajar/Open
Refer to Wiring Diagram Set 117 (Fusion/Milan/MKZ, Fusion Hybrid, Milan Hybrid, MKZ Hybrid), Remote Keyless Entry and Alarm for schematic and connector information. Diagrams By Number
Normal Operation
The hood switch is a normally closed switch. The Smart Junction Box (SJB) receives the hood switch status through circuit CPL25 (hood switch ajar sense circuit), the hood switch, and the hood switch ground circuit GD123. When the hood is open, the hood switch opens, removing the ground to the SJB.
- DTC B1520 (Hood Switch Circuit Open) - an on-demand DTC that sets when there is an open in the circuit between the hood switch and the SJB, an open in the ground circuit to the hood switch, or the hood switch is stuck open during the on-demand self-test. If the hood is detected as always being open, the perimeter alarm will never arm for the hood.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Hood switch
- SJB
PINPOINT TEST B: THE ALARM SYSTEM DOES NOT OPERATE CORRECTLY - ALARM DOES NOT ACTIVATE WITH HOOD AJAR/OPEN
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
NOTE: Failure to disconnect the battery when instructed will result in false resistance readings. Refer to Battery, Mounting and Cables Battery Disconnect.
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B1 CHECK THE HOOD SWITCH
- Ignition OFF.
- Disconnect: Hood Switch C127.
- Measure the resistance between the hood switch C127-1, component side and the hood switch C127-2, component side while pressing the hood switch plunger in and then releasing it.
- Is the resistance less than 5 ohms with the hood switch plunger pressed and greater than 10,000 ohms with the hood switch plunger released?
Yes
GO to B2.
No
INSTALL a new hood switch. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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B2 CHECK THE HOOD SWITCH CIRCUIT CPL25 (HOOD SWITCH AJAR 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 B3.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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B3 CHECK CIRCUIT CPL25 (HOOD SWITCH AJAR SENSE CIRCUIT) FOR AN OPEN
- Measure the resistance between the SJB C2280f-10, circuit CPL25 (BU/OG), harness side and the hood switch C127-1, circuit CPL25 (BU/OG), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to B4.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
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B4 CHECK CIRCUIT GD123 (HOOD SWITCH GROUND CIRCUIT) FOR AN OPEN
- Disconnect: Negative Battery Cable.
- Measure the resistance between the hood switch C127-2, circuit GD123 (BK/GY), harness side and ground.
- Is the resistance less than 5 ohms?
Yes
GO to B5.
No
REPAIR the circuit. CONNECT the negative battery cable. CLEAR the DTCs. REPEAT the self-test.
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B5 CHECK THE SJB FOR CORRECT OPERATION
- Connect: Negative Battery Cable.
- 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. CYCLE each key to the ON position for a minimum of 6 seconds to PROGRAM the Remote Keyless Entry (RKE) function of the Integrated Keyhead Transmitter (IKT) keys. CLEAR the DTCs. REPEAT the self-test. 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. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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