Pinpoint Tests AT: The Trunk Ajar Message Center Warning Indicator Is Never/Always On
Instrumentation, Message Center and Warning Chimes
Pinpoint Test AT: The Trunk Ajar Message Center Warning Indicator Is Never/Always On (Hybrid)
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 decklid ajar input circuit. The luggage compartment lid ajar switch is grounded through an external ground circuit. When the luggage compartment lid is ajar, the luggage compartment lid latch removes the ground to the luggage compartment lid ajar switch input. 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 decklid ajar input circuit, the SJB sends a message to the IPC to turn on the trunk ajar message center indicator.
If the decklid ajar status message is missing for less than 5 seconds, the trunk ajar message center warning indicator remains in the last state (on or off) based upon the last known good message received. If the decklid ajar status message is missing for greater than 5 seconds, the IPC sets DTC U0140:00 and defaults the decklid ajar message center warning indicator on.
NOTE: If DTC U0140:00 is set in the SJB, other symptoms may also be present in the IPC such as high beam indicator, RH/LH turn indicators, instrument panel backlighting and Tire Pressure Monitoring System (TPMS).
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 AT: THE TRUNK AJAR MESSAGE CENTER WARNING INDICATOR IS NEVER/ALWAYS ON (HYBRID)
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.
-------------------------------------------------
AT1 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 door ajar message center warning indicator turn on?
Yes
GO to AT2.
No
INSTALL a new IPC. REFER to Instrument Panel Cluster (IPC) Instrument Panel Cluster (IPC). TEST the system for normal operation.
-------------------------------------------------
AT2 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 AT3.
-------------------------------------------------
AT3 CHECK THE LUGGAGE COMPARTMENT LID LATCH OPERATION
- Press the luggage compartment lid release switch.
- Does the luggage compartment lid release function operate?
Yes
GO to AT4.
No
REFER to Handles, Locks, Latches and Entry Systems Testing and Inspection.
-------------------------------------------------
AT4 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 AT5.
-------------------------------------------------
AT5 CHECK THE DECKLID 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 AT6.
No
REPAIR the circuit. TEST the system for normal operation.
-------------------------------------------------
AT6 CHECK THE DECKLID 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 AT7.
No
REPAIR the circuit. TEST the system for normal operation.
-------------------------------------------------
AT7 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.
-------------------------------------------------