Pinpoint Test Ax: The Trunk Ajar Message Is Inoperative/Always On

WARNING: This page is about a different car, the 2010 Mercury Milan, 2010 Lincoln MKZ, and 2010 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: 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 .

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) . TEST the system for normal operation.
AX2 RETRIEVE THE RECORDED DTCs FROM THE SELF-TEST IPC
- Retrieve the recorded DTCs from the IPC self-test.
- Is DTC U0140:00 recorded?
- Yes: Go To PINPOINT TEST BM .
- No: GO to AX3.
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 .
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.
  
  Fig 1: Measuring Voltage Between Luggage Compartment Lid Latch C429-1, Circuit CPL58 (GY/OG), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is the voltage greater then 10 volts?
- Yes : INSTALL a new luggage compartment lid latch. REFER to HANDLES, LOCKS, LATCHES AND ENTRY SYSTEMS . TEST the system for normal operation.
- No : GO to AX5.
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.
  
  Fig 2: Measuring Resistance Between SJB C2280C-16, Circuit CPL58 (GY/OG), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance greater than 10,000 ohms?
- Yes : GO to AX6.
- No : REPAIR the circuit. TEST the system for normal operation.
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.
  
  Fig 3: Connecting Fused Jumper Wire Between Luggage Compartment Lid Latch C429-1, Circuit CPL58 (GY/OG), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Measure the resistance between the SJB C2280c-16, circuit CPL58 (GY/OG), harness side and ground.
  
  Fig 4: Measuring Resistance Between SJB C2280C-16, Circuit CPL58 (GY/OG), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
- Yes : GO to AX7.
- No : REPAIR the circuit. TEST the system for normal operation.
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 . 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.