Pinpoint Test A: All Door Locks Are Inoperative
Handles, Locks, Latches and Entry Systems
Pinpoint Tests
Pinpoint Test A: All Door Locks Are Inoperative
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 - MKZ
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.
Fusion/Milan
The SJB supplies voltage to the lock all relay, the unlock driver door relay or unlock all relay based upon input from the door lock control switches, the RKE transmitter, or the keyless entry keypad. Upon a lock request, the SJB supplies voltage on the all door lock circuit and ground on the driver and passenger door lock circuits. 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
- Luggage compartment lid release solenoid (part of the luggage compartment lid latch)
- SJB
PINPOINT TEST A: ALL DOOR LOCKS ARE INOPERATIVE
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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A1 VERIFY THE OPERATION OF BOTH DOOR LOCK CONTROL SWITCHES
- Press the lock and unlock button on both door lock control switches while observing the door lock operation.
- Are the door locks inoperative from both switches?
Yes
For MKZ, multiple failures exist if all locks are inoperative. CHECK the symptom(s) and GO to Symptom Chart - Electrical. Symptom Related Diagnostic Procedures
For Fusion and Milan, GO to A2.
No
GO to Pinpoint Test D. Pinpoint Test D: All Door Locks Are Inoperative From One Switch
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A2 VERIFY ALL DOOR LOCKS ARE INOPERATIVE
- Press the lock and unlock buttons from a door lock control switch while observing the door locks.
- Are all the door locks inoperative from both switch positions (lock and unlock)?
Yes
VERIFY the SJB fuse 17 (20A) is OK. If OK, GO to A3.
If not OK, GO to A5.
No
GO to Symptom Chart - Electrical. Symptom Related Diagnostic Procedures
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A3 CHECK THE ALL LOCK CIRCUIT FOR AN OPEN
- Disconnect: LH Front Door Latch C525 .
- Disconnect: SJB C228d .
- Measure the resistance between the SJB C2280d-6, circuit CPL11 (GY/BN), harness side and the LH front door latch C525-2, circuit CPL11 (GY/BN), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to A4.
No
REPAIR circuit CPL11 (GY/BN) for an open. TEST the system for normal operation.
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A4 CHECK THE POWER DOOR LOCK RELAY GROUND CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect: Negative Battery Cable .
- 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 A8.
No
REPAIR circuit GD126 (BK/WH) for an open. TEST the system for normal operation.
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A5 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 A7.
No
GO to A6.
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A6 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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A7 CHECK THE ALL LOCK CIRCUIT FOR A SHORT TO GROUND
- Operate the door lock actuators by pressing LOCK on the door lock control switch.
- Is the SJB fuse 17 (20A) OK?
Yes
REPAIR circuit CPL51 (BU/GN) or 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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A8 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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