Pinpoint Test K: The Keyless Entry Keypad Illumination Is Inoperative

Refer to appropriate SYSTEM WIRING DIAGRAMS article, Remote Keyless Entry and Alarm for schematic and connector information.

Normal Operation 

The keyless entry keypad receives voltage through circuit 1523 (DG). With the keyless entry keypad illumination activated, the driver door module (DDM) grounds circuit 66 (LB) to illuminate the keyless entry keypad.

This pinpoint test is intended to diagnose the following:

• Wiring, terminals or connectors
• Keyless entry keypad
• DDM

PINPOINT TEST K: THE KEYLESS ENTRY KEYPAD ILLUMINATION IS INOPERATIVE 

1. K1 CHECK FOR VOLTAGE TO THE KEYLESS ENTRY KEYPAD 
   • Disconnect: Keyless Entry Keypad C530
   Fig 1: Checking Circuit For Voltage
   Courtesy of FORD MOTOR CO.
   • Measure the voltage between the keyless entry keypad C530-2, circuit 1523 (DG), harness side and ground.
   • Is the voltage greater than 10 volts? 
   1. YES  : Go to  K2.
   2. NO  : REPAIR the circuit. TEST the system for normal operation.
2. K2 CHECK CIRCUIT 66 (LB) FOR GROUND 
   • Enter the following diagnostic mode on the diagnostic tool: DDM DataLogger
   Fig 2: Checking Circuit For Ground
   Courtesy of FORD MOTOR CO.
   • Measure the resistance between the keyless entry keypad C530-5, circuit 66 (LB), harness side and ground.
   • Trigger the DDM LIGHT active command while observing the resistance reading.
   • Is the resistance less than 5 ohms? 
   1. YES  : INSTALL a new keyless entry keypad. REFER to Keyless Entry Keypad . TEST the system for normal operation.
   2. NO  : Go to  K3.
3. K3 CHECK CIRCUIT 66 (LB) FOR AN OPEN 
   • Disconnect: DDM C501a
   Fig 3: Checking Circuit For Open
   Courtesy of FORD MOTOR CO.
   • Measure the resistance between the keyless entry keypad C530-5, circuit 66 (LB), harness side and the DDM C501a-26, circuit 66 (LB), harness side.
   • Is the resistance less than 5 ohms? 
   1. YES  : Go to  K4.
   2. NO  : REPAIR the circuit. TEST the system for normal operation.
4. K4 CHECK FOR CORRECT DDM OPERATION 
   • Disconnect all DDM connectors.
   • Check for:
     • corrosion
     • damaged pins
     • pushed-out pins
   • Connect all DDM connectors and make sure they seat correctly.
   • Operate the system and verify the concern is still present.
   • Is the concern still present? 
   1. YES  : INSTALL a new DDM. REFER to MULTIFUNCTION ELECTRONIC MODULES article. PROGRAM all the RKE transmitters. REFER to Remote Keyless Entry Transmitter Programming . CLEAR the DTCs. REPEAT the self-test.
   2. NO  : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.