The drivers door lock on my 99 fails to lock with door switch or fob
will work manually or by key cyclinder. Unlock function works fine.
Tried to manually work door lock handle back and forth to see if I
could possibly free it electrically, but it only did the trick once.
How can I obtain the info on how to remove interior panel to access
door control unit
thanks
Chuck

 

Before you tear the panel off, try checking the plug on the harness inside the boot that goes from the door to the body of the car. They have been known to come loose, get corrosion, or break wires in this area. You can also try pushing the lock button and holding it while you move the door back and fourth. If the door suddenly locks, you have a broken wire in that harness. It will probably be one of those nasty ones that are fine on the outside, but the conductor is broken on the inside of the insulation. You can work the boot out of the body to gain access to the wires.

IF that is not the case, it is probably the left door control module that has failed. It connects both wires of the lock solenoid to ground until you request either a lock or unlock condition. At that point, it switches one wire to 12V, and the solenoid plunger moves in the correct direction to carry out your request. When you release the button, the wire switches back to ground and the socenoid returns to it's center position.(neutral) When you request the other direction, it provides 12V. to the other wire, and the solenoid plunger goes the other way.
The L.H. door control module is located Behind the LH door trim panel, bottom center of the door, rear of the speaker.

Removal Procedure
To reduce the chance of damage to the trim panel leave the switch in the panel until after the panel is removed from the door.
1. Lower the door window.
2. Remove the inside handle bezel.
3. Pull the door inside handle open to access the openings to the bezel locking tabs.
4. Insert a screwdriver in the lower opening. Tip the screwdriver up while pulling on the bezel releasing the lower locking tab.
5. Insert the screwdriver in the upper opening. Tip the screwdriver down while pulling on the bezel releasing the upper and the forward locking tabs.
6. Grasp the bezel firmly, pull the bezel releasing the rear locking tabs.
7. Remove the bezel.
8. Remove the pull handle plug.
9. Remove the screws behind the pull handle plug.
10. Important: To avoid breaking the trim panel fasteners be sure to insert the fastener removal tool between the male fastener, which is attached to the trim panel, and the female retainer which is in the door. Do Not insert the tool between the head of the female retainer and the door.
For better sight access to the fasteners start by first prying out the fastener at the rear of the trim panel that is approximately 50 mm (2 in) up from the trim panel seam.
Pry out the remaining trim panel fasteners working your way forward.
11. Lift the trim panel up off the upper retainers and reposition the panel by the door.
12. Remove the harness connector from the switch.
13. Remove the trim panel with absorber, switch, and speaker grill.
14. Remove any trim panel upper retainers that remained on the door.
15. Transfer parts as necessary.

Installation Procedure
1. Reinstall any loose upper retainers to the door trim panel.
2. Position the trim panel near the door and install the switch harness to the switch.
3. Install the trim panel to the top of the door engaging the upper retainers.
4. Align all the trim panel side and lower fasteners with the retainers in the door.
5. Press the trim panel firmly to the door at each fastener location.
Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.
6. Install the screws behind the pull handle.
Tighten
Tighten the pull handle screws to 6 N-m (53 lb in).
7. Install the pull handle plug.
8. Install the bezel to the handle.
1. Position the bezel around the inside door handle.
2. Push firmly on the bezel engaging the bezel locking tabs to the door.


Hope this helps.