Pinpoint Test F: The Keyless Entry Keypad Illumination Is Inoperative

WARNING: This page is about a different car, the 2004 Mercury Mountaineer and 2004 Ford Explorer. However, it is still accessible from the selected car via links, so may be relevant.

F1 CHECK THE KEYPAD SWITCH PIDS
- Enter the following diagnostic mode on the diagnostic tool: Vehicle Security Module KEYPAD PIDS.
- Press each keypad button while viewing the vehicle security module KEYPAD PIDS.
- Do the PID values agree with the keypad button positions?
Yes

GO to F2.

No

To diagnose the incorrect keypad PID values, GO to PINPOINT TEST B .
F2 CHECK THE VEHICLE SECURITY MODULE OUTPUT FUNCTION
- Enter the following diagnostic mode on the diagnostic tool: Activate the keypad backlighting on and off active commands.
- Trigger LIGHT ON then OFF.
- Does the keypad backlighting turn on and off when commanded?
Yes

GO to F5.

No

GO to F3.
F3 CHECK CIRCUIT 1205 (BK) FOR AN OPEN
- Key in OFF position.
- Disconnect: Keyless Entry Keypad C500.
- Measure the resistance between the keyless entry keypad C500-5, circuit 1205 (BK), harness side and ground.
  
  Fig 1: Checking Circuit 1205 (BK) For An Open
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
Yes

GO to F4.

No

REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
F4 CHECK CIRCUIT 66 (LB) FOR AN OPEN OR SHORT TO GROUND
- Disconnect: Vehicle Security Module C3203f.
- Measure the resistance between the keyless entry keypad C500-2, circuit 66 (LB), harness side and the vehicle security module C3203f-6, circuit 66 (LB), harness side; and between the vehicle security module C3203f-6, circuit 66 (LB), harness side and ground.
  
  Fig 2: Checking Circuit 66 (LB) For An Open Or Short To Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms between the keyless entry keypad and the vehicle security module and greater than 10,000 ohms between the vehicle security module and ground?
Yes

INSTALL a new keyless entry keypad. refer to KEYLESS ENTRY KEYPAD . CLEAR the DTCs. REPEAT the self-test.

No

REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
F5 CHECK FOR CORRECT VEHICLE SECURITY MODULE OPERATION
- Disconnect all the vehicle security module connectors.
- Check for:
  - for corrosion
  - for pushed-out pins
- Connect all the vehicle security module 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 vehicle security module. REFER to MODULE COMMUNICATIONS NETWORK . CLEAR the DTCs. REPEAT the vehicle security module self-test.

No

The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.