Pinpoint Tests AX: The Trunk Ajar Message Is Inoperative/Always On
Instrumentation, Message Center and Warning Chimes
Pinpoint Test AX: The TRUNK AJAR Message Is Inoperative/Always On
Refer to Wiring Diagram Set 113 (Fusion/Milan/MKZ, Fusion Hybrid, Milan Hybrid, MKZ Hybrid), Luggage Compartment for schematic and connector information. Diagrams By Number
Normal Operation
The Instrument Panel Cluster (IPC) receives the trunk ajar status from the Smart Junction Box (SJB) over the Medium Speed Controller Area Network (MS-CAN) communication bus. The luggage compartment lid ajar switch (part of the luggage compartment lid latch) is hardwired to the SJB through the trunk ajar input circuit. The luggage compartment lid ajar switch is grounded externally. When the luggage compartment lid is ajar, the luggage compartment lid latch removes the ground to the luggage compartment lid ajar switch input to the SJB. When the luggage compartment lid is closed, the luggage compartment lid release grounds the luggage compartment lid ajar switch.
When the SJB detects an open on the trunk ajar input circuit, the SJB sends a message to the IPC to turn on the TRUNK AJAR message in the message center.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Luggage compartment lid ajar switch (part of the luggage compartment lid latch)
- SJB
- IPC
PINPOINT TEST AX: THE TRUNK AJAR MESSAGE IS INOPERATIVE/ALWAYS ON
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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AX1 CHECK THE MESSAGE CENTER OPERATION
- Close all doors, hood and luggage compartment lid.
- Ignition ON.
- Open the driver door while monitoring the message center displays.
- Does the message center display DRIVER DOOR AJAR?
Yes
GO to AX2.
No
INSTALL a new IPC. REFER to Instrument Panel Cluster (IPC) Instrument Panel Cluster (IPC). TEST the system for normal operation.
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AX2 RETRIEVE THE RECORDED DTCs FROM THE IPC SELF-TEST
- Retrieve the recorded DTCs from the IPC self-test.
- Is DTC U0140:00 recorded?
Yes
GO to Pinpoint Test BM. Pinpoint Tests BM: DTC U0140:00
No
GO to AX3.
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AX3 CHECK THE LUGGAGE COMPARTMENT LID LATCH OPERATION
- Press the luggage compartment lid release switch on the instrument panel.
- Does the luggage compartment lid release function operate?
Yes
GO to AX4.
No
REFER to Handles, Locks, Latches and Entry Systems Testing and Inspection.
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AX4 CHECK THE LUGGAGE COMPARTMENT LID AJAR SWITCH
- Ignition OFF.
- Disconnect: Luggage Compartment Lid Latch C429 .
- Ignition ON.
- Measure the voltage between the luggage compartment lid latch C429-1, circuit CPL58 (GY/OG), harness side and ground.
- Is the voltage greater then 10 volts?
Yes
INSTALL a new luggage compartment lid latch. REFER to Handles, Locks, Latches and Entry Systems Service and Repair. TEST the system for normal operation.
No
GO to AX5.
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AX5 CHECK THE TRUNK AJAR INPUT CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: SJB C2280c .
- Measure the resistance between the SJB C2280c-16, circuit CPL58 (GY/OG), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to AX6.
No
REPAIR the circuit. TEST the system for normal operation.
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AX6 CHECK THE TRUNK AJAR INPUT CIRCUIT FOR AN OPEN
- Disconnect: Negative Battery Cable .
- Connect a fused jumper wire between the luggage compartment lid latch C429-1, circuit CPL58 (GY/OG), harness side and ground.
- Measure the resistance between the SJB C2280c-16, circuit CPL58 (GY/OG), harness side and ground.
- Is the resistance less than 5 ohms?
Yes
GO to AX7.
No
REPAIR the circuit. TEST the system for normal operation.
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AX7 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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