Diesel Data: Automotive Repair

Pinpoint Test V: Manual Door Lock Cylinder Inoperative




Handles, Locks, Latches and Entry Systems

Pinpoint Test V: Manual Door Lock Cylinder Inoperative

Normal Operation

The door lock cylinder is connected to the door latch via a lock rod and can be used to manually lock/unlock a door.

This pinpoint test is intended to diagnose the following:

- Bent or binding lock rod and lever
- Door lock cylinder
- Door latch

PINPOINT TEST V: MANUAL DOOR LOCK CYLINDER INOPERATIVE

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V1 CHECK THE LOCK AND UNLOCK OPERATION

- Insert a key into the lock cylinder and rotate the lock cylinder to the lock and unlock positions.
- Does the door lock cylinder freely rotate without locking and unlocking the door?

Yes
GO to V2.

No
GO to V3.

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V2 CHECK THE DOOR LOCK CYLINDER

- Remove the door lock cylinder. Refer to Door Lock Cylinder Service and Repair.
- Operate the door lock cylinder with the key while holding the lever on the lock cylinder.
- Does the key in the door lock cylinder rotate freely while the lever is stationary?

Yes
INSTALL a new door lock cylinder. REFER to Door Lock Cylinder Service and Repair. TEST the system for normal operation.

No
GO to V5.

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V3 CHECK THE LOCK CYLINDER OPERATION AFTER LUBRICATION

- Spray a lock lubricant such as Motorcraft(TM) XL-1 into the lock cylinder opening for a couple seconds.
- Operate the door lock cylinder with the key.
- Does the door lock and unlock using the door lock cylinder?

Yes
The concern was caused by an insufficiently lubricated lock cylinder. SPRAY a multi-purpose grease such as Motorcraft(TM) XL-5 into the lock cylinder for a couple seconds to provide long term lubrication.

No
GO to V4.

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V4 CHECK THE DOOR LOCK CYLINDER

- Remove the door lock cylinder. Refer to Door Lock Cylinder Service and Repair.
- Operate the door lock cylinder with the key.
- Does the door lock cylinder rotate freely?

Yes
GO to V5.

No
INSTALL a new door lock cylinder. REFER to Door Lock Cylinder Service and Repair. TEST the system for normal operation.

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V5 CHECK THE DOOR LOCK CYLINDER LINKAGE

- Operate the door lock cylinder while observing the linkage.
- Is the door lock cylinder rod and lever 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. TEST the system for normal operation.

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