Pinpoint Test C: A Single/More Than One Door Lock Is Inoperative
Handles, Locks, Latches and Entry Systems
Pinpoint Tests
Pinpoint Test C: A Single/More Than One Door Lock Is Inoperative - MKZ
Refer to Wiring Diagram Set 110 (Fusion/Milan/MKZ, Fusion Hybrid/Milan Hybrid), Power Door Locks for schematic and connector information. Diagrams By Number
Normal Operation
The Smart Junction Box (SJB) supplies voltage and ground to all the passenger door lock actuators by controlling the lock all and unlock all relays. The Driver Door Module (DDM) supplies voltage and ground only to the driver door lock actuator. The SJB receives inputs from the RH door lock control switch, keyless entry keypad, and the Remote Keyless Entry (RKE) transmitter. The DDM only receives input from the LH door lock control switch. Both modules share the information obtained from the inputs over the Medium Speed Controller Area Network (MS-CAN). Upon a lock request, the SJB supplies voltage on the passenger door lock circuit and ground on the passenger door unlock circuit, and the DDM supplies voltage on the driver door lock circuit and ground on the driver door unlock circuit. Upon an unlock request, the voltage and ground are reversed on the previously listed circuits. When the door lock and unlock relays are not energized they are connected to ground. A dedicated SJB ground circuit is provided only for the lock and unlock relays.
This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- Door lock actuator (part of the door latch)
- Luggage compartment lid release solenoid (part of the luggage compartment latch)
- DDM
- SJB
PINPOINT TEST C: A SINGLE/MORE THAN ONE DOOR LOCK IS INOPERATIVE - MKZ
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.
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C1 CHECK THE DOOR LATCH FOR BINDING
- Lock and unlock the inoperative door lock using the door lock rod.
- Does the door lock and unlock?
Yes
GO to C3.
No
GO to C2.
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C2 CHECK THE LOCK ROD FOR BINDING
- Operate the door lock rod manually while observing the door lock rod for any binding or if the rod is bent.
- Is the door lock rod bent or binding?
Yes
REPAIR as necessary. TEST the system for normal operation.
No
INSTALL a new door latch. REFER to Front Door Latch Front Door Latch or Rear Door Latch Rear Door Latch. TEST the system for normal operation.
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C3 CHECK FOR COMMUNICATION WITH THE DDM AND SJB
- Enter the following diagnostic mode on the scan tool: Network Test .
- Does the SJB or DDM fail the network test?
Yes
REFER to Information Bus.
No
GO to C4.
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C4 CHECK THE PASSENGER DOOR LOCKS
- Ignition OFF.
- Operate the door locks from the passenger door lock control switch.
- Are all of the passenger door locks inoperative?
Yes
VERIFY the SJB fuse 17 (20A) is OK. If OK, GO to C5.
If not OK, GO to C8.
No
GO to C11.
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C5 CHECK THE POWER DOOR LOCK RELAY GROUND CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect: Negative Battery Cable .
- Disconnect: SJB C2280d .
- Measure the resistance between the SJB C2280d-7, circuit GD126 (BK/WH), harness side and ground.
- Is the resistance less than 5 ohms?
Yes
GO to C6.
No
REPAIR circuit GD126 (BK/WH) for an open. TEST the system for normal operation.
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C6 CHECK THE LOCK CIRCUIT FOR AN OPEN
- Disconnect: RH Front Door Latch C603 .
- Measure the resistance between the RH front door latch C603-2, circuit CPL11 (GY/BN), harness side and the SJB C2280d-6, circuit CPL11 (GY/BN), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to C7.
No
REPAIR circuit CPL11 (GY/BN) for an open. TEST the system for normal operation.
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C7 CHECK THE UNLOCK CIRCUIT FOR AN OPEN
- Measure the resistance between the RH front door latch C603-10, circuit CPL52 (VT/GY), harness side and the SJB C2280d-27, circuit CPL52 (VT/GY), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to C19.
No
REPAIR circuit CPL52 (VT/GY) for an open. TEST the system for normal operation.
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C8 CHECK THE LUGGAGE COMPARTMENT LID RELEASE OUTPUT CIRCUIT FOR A SHORT TO GROUND
- Install a new SJB fuse 17 (20A).
- Operate the luggage compartment lid release by pressing the luggage compartment lid release switch.
- Is the SJB fuse 17 (20A) OK?
Yes
GO to C10.
No
GO to C9.
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C9 CHECK THE LUGGAGE COMPARTMENT LID RELEASE SOLENOID
- Install a new SJB fuse 17 (20A).
- Disconnect: Luggage Compartment Lid Release Solenoid C429 .
- Operate the luggage compartment lid release by pressing the luggage compartment lid release switch.
- Is the SJB fuse 17 (20A) OK?
Yes
INSTALL a new luggage compartment lid latch. REFER to Luggage Compartment Lid Latch Service and Repair.
No
REPAIR circuit CPL59 (BN/BU) for a short to ground. TEST the system for normal operation.
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C10 CHECK THE LOCK CIRCUIT FOR A SHORT TO GROUND
- Operate the door lock actuators by pressing LOCK on the passenger door lock control switch.
- Is the SJB fuse 17 (20A) OK?
Yes
REPAIR circuit CPL52 (VT/GY) for a short to ground. TEST the system for normal operation.
No
REPAIR circuit CPL11 (GY/BN) for a short to ground. TEST the system for normal operation.
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C11 CHECK THE DRIVER DOOR LOCK
- Check to see if the driver door lock is the inoperative lock.
- Is the driver door lock inoperative?
Yes
GO to C12.
No
GO to C16.
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C12 CHECK THE DRIVER DOOR LOCK CIRCUIT FOR VOLTAGE
- Disconnect: LH Front Door Latch C525 .
- NOTE: The DDM only supplies voltage to the actuator momentarily. It is important to monitor the meter while pressing the door lock control switch.
- While pressing the door lock control switch in the LOCK position, measure the voltage between the LH front door latch C525-2, circuit CPL02 (VT/GN), harness side and ground.
- Is the voltage momentarily greater than 10 volts?
Yes
GO to C13.
No
GO to C14.
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C13 CHECK THE DRIVER UNLOCK CIRCUIT FOR VOLTAGE
- NOTE: The DDM only supplies voltage to the actuator momentarily. It is important to monitor the meter while pressing the door lock control switch.
- While pressing the door lock control switch in the UNLOCK position, measure the voltage between the LH front door latch C525-10, circuit CPL51 (BU/GN), harness side and ground.
- Is the voltage momentarily greater than 10 volts?
Yes
INSTALL a new driver door latch. REFER to Front Door Latch Front Door Latch. TEST the system for normal operation.
No
GO to C15.
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C14 CHECK THE DRIVER LOCK CIRCUIT FOR AN OPEN OR A SHORT TO GROUND
- Disconnect: DDM C568b .
- Measure the resistance between the LH front door latch C525-2, circuit CPL02 (VT/GN), harness side and the DDM C568b-11, circuit CPL02 (VT/GN), harness side; and between the LH front door latch C525-2, circuit CPL02 (VT/GN), harness side and ground.
- Is the resistance less than 5 ohms between the LH front door latch and the DDM, and greater than 10,000 ohms between the LH front door latch and ground?
Yes
GO to C15.
No
REPAIR circuit CPL02 (VT/GN). TEST the system for normal operation.
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C15 CHECK THE DRIVER UNLOCK CIRCUIT FOR AN OPEN OR A SHORT TO GROUND
- Disconnect: DDM C568b .
- Measure the resistance between the LH front door latch C525-10, circuit CPL51 (BU/GN), harness side and the DDM C568b-10, circuit CPL51 (BU/GN), harness side; and between the LH front door latch C525-10, circuit CPL51 (BU/GN), harness side and ground.
- Is the resistance less than 5 ohms between the LH front door latch and the DDM, and greater than 10,000 ohms between the LH front door latch and ground?
Yes
GO to C18.
No
REPAIR circuit CPL51 (BU/GN). TEST the system for normal operation.
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C16 CHECK THE PASSENGER LOCK CIRCUIT FOR VOLTAGE
- Disconnect: Suspect Door Latch .
- NOTE: The SJB only supplies voltage to the actuator momentarily. It is important to monitor the meter while pressing the door lock control switch.
- While pressing the door lock control switch in the LOCK position, measure the voltage between the suspect door latch and ground as follows:
- Is the voltage momentarily greater than 10 volts?
Yes
GO to C17.
No
REPAIR circuit CPL11 (GY/BN) for an open. TEST the system for normal operation.
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C17 CHECK THE PASSENGER UNLOCK CIRCUIT FOR VOLTAGE
- NOTE: The SJB only supplies voltage to the actuator momentarily. It is important to monitor the meter while pressing the door lock control switch.
- While pressing the door lock control switch in the UNLOCK position, measure the voltage between the suspect door latch and ground as follows:
- Is the voltage momentarily greater than 10 volts?
Yes
INSTALL a new door latch for the door lock actuator in question. REFER to Front Door Latch Front Door Latch or Rear Door Latch Rear Door Latch. TEST the system for normal operation.
No
REPAIR circuit CPL52 (VT/GY) for an open. TEST the system for normal operation.
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C18 CHECK FOR CORRECT DDM OPERATION
- Disconnect all the DDM connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the DDM 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 DDM. REFER to Body Control Systems. 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. TEST the system for normal operation.
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C19 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 Body Control Systems. 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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