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Home >> Mercury >> 2008 >> Milan Base, 3.0 1, FWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 1692 (Handles, Locks, Latches And Entry Systems) >> Diagnostic Tests >> Locks, Latches and Entry Systems >> Pinpoint Tests >> Pinpoint Test H: The Keyless Entry Keypad Illumination Is Inoperative/Does Not Operate Correctly

Pinpoint Test H: The Keyless Entry Keypad Illumination Is Inoperative/Does Not Operate Correctly

WARNING: This page is about a different car, the 2010 Lincoln Town Car. However, it is still accessible from the selected car via links, so may be relevant.

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

Normal Operation 

When the driver door module (DDM) detects a keyless entry keypad button is pressed, the DDM supplies ground to the keyless entry keypad on circuit 66 (LB). The keypad receives voltage through circuit 1524 (DB).

This pinpoint test is intended to diagnose the following:

PINPOINT TEST H: THE KEYLESS ENTRY KEYPAD ILLUMINATION IS INOPERATIVE/DOES NOT OPERATE CORRECTLY 

NOTE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
  1. H1 CHECK THE KEYLESS ENTRY KEYPAD 
    • Observe the door locks while pressing the keyless entry keypad 7/8 and 9/0 buttons.
    • Do the doors lock? 
    1. YES  : Go to  H2.
    2. NO  : Go to Pinpoint Test G  .
  2. H2 CHECK THE KEYLESS ENTRY KEYPAD ILLUMINATION 
    • Observe the keyless entry keypad illumination.
    • Is the keyless entry keypad illumination always on? 
    1. YES  : Go to  H3.
    2. NO  : Go to  H4.
  3. H3 CHECK CIRCUIT 66 (LB) FOR A SHORT TO GROUND 
    • Key in OFF position.
    • Disconnect: DDM C501a
    • Observe the keyless entry keypad illumination.
    • Is the keyless entry keypad illumination on? 
    1. YES  : REPAIR the circuit. TEST the system for normal operation.
    2. NO  : Go to  H7
  4. H4 CHECK FOR VOLTAGE TO THE KEYPAD 
    • Disconnect: Keyless Entry Keypad C500
      • Fig 1: Checking Circuit For Voltage
      GF0013244Courtesy of FORD MOTOR CO.
    • Measure the voltage between the keyless entry keypad C500-2, circuit 1524 (DB), harness side and ground.
    • Is the voltage greater than 10 volts? 
    1. YES  : Go to  H5.
    2. NO  : VERIFY the central junction box (CJB) fuse 19 (7.5A) is OK. If OK, REPAIR the circuit for an open. TEST the system for normal operation.
  5. H5 CHECK FOR DDM OUTPUT 
    • Enter the following diagnostic mode on the diagnostic tool: DDM DataLogger
    • Active command the DDM keypad illumination PID (LIGHT) on.
      • Fig 2: Measuring Voltage
      GF0047534Courtesy of FORD MOTOR CO.
    • Measure the voltage between the keyless entry keypad C500-2, circuit 1524 (DB), harness side, and the keyless entry keypad C500-5, circuit 66 (LB), harness side.
    • Is the voltage greater than 10 volts? 
    1. YES  : INSTALL a new keyless entry keypad. REFER to Keyless Entry Keypad .
    2. NO  : Go to  H6.
  6. H6 CHECK CIRCUIT 66 (LB) FOR AN OPEN 
    • Key in OFF position.
    • Disconnect: DDM C501a
      • Fig 3: Checking Circuit For Open
      GF0013246Courtesy of FORD MOTOR CO.
    • Measure the resistance between the keyless entry keypad C500-5, 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  H7.
    2. NO  : REPAIR the circuit. TEST the system for normal operation.
  7. H7 CHECK FOR CORRECT DDM OPERATION 
    • Disconnect all the DDM connectors.
    • Check for:
      • corrosion
      • damaged pins
      • pushed-out pins
    • Connect all the 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. TEST the system for normal operation.
    2. 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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