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Pinpoint Test K: The Ambient Lighting Is Inoperative - Fusion/MILAN

WARNING: This page is about a different car, the 2011 Mercury Milan, 2011 Lincoln MKZ, and 2011 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
  1. K1 CHECK FOR VOLTAGE TO THE AMBIENT LIGHTING MODULE 
    • Ignition OFF.
    • Disconnect: Ambient Lighting Module C3256.
    • Ignition ON.
    • Measure the voltage between the ambient lighting module C3256-1, circuit CBX07 (GN/RD), harness side and ground.
      Fig 1: Measuring Voltage Between Ambient Lighting Module C3256-1, Circuit CBX07 (GN/RD), Harness Side And Ground
      G06099282Courtesy of FORD MOTOR CO.
    • Is the voltage greater than 10 volts? 
    • Yes  : GO to K2.
    • No  : VERIFY the Smart Junction Box (SJB) fuse 41 (15A) is OK. If OK, REPAIR the circuit CBX07 (GN/RD) for an open. TEST the system for normal operation. If not OK, REFER to the appropriate SYSTEM WIRING DIAGRAMS article to identify the possible causes of the circuit short.
  2. K2 CHECK THE INPUT FROM THE AMBIENT LIGHTING SWITCH 
    • While pressing and releasing the ambient lighting switch, measure the voltage between the ambient lighting module C3256-2, circuit CLN54 (BN/YE), harness side and ground.
      Fig 2: Measuring Voltage Between Ambient Lighting Module C3256-2 And Ground
      G06065407Courtesy of FORD MOTOR CO.
    • Is the voltage greater than 10 volts with the switch pressed and 0 volts with the switch released? 
    • Yes  : GO to  K6.
    • No  : If voltage is always present, GO to K3.

      If no voltage is present, GO to  K4.

  3. K3 CHECK THE AMBIENT LIGHTING SWITCH INPUT CIRCUIT FOR A SHORT TO VOLTAGE 
    • Ignition OFF.
    • Disconnect: Traction Control/Ambient Lighting Switch C2304.
    • Ignition ON.
    • Measure the voltage between the ambient lighting module C3256-2, circuit CLN54 (BN/YE), harness side and ground.
      Fig 3: Measuring Voltage Between Ambient Lighting Module C3256-2 And Ground
      G06065407Courtesy of FORD MOTOR CO.
    • Is any voltage present? 
  4. K4 CHECK FOR VOLTAGE TO THE AMBIENT LIGHTING SWITCH 
    • Ignition OFF.
    • Connect: Ambient Lighting Module C3256.
    • Disconnect: Traction Control/Ambient Lighting Switch C2304.
    • Ignition ON.
    • Measure the voltage between the ambient lighting switch C2304-5, circuit CBP41 (BU), harness side and ground.
      Fig 4: Measuring Voltage Between Ambient Lighting Switch C2304-5, Circuit CBP41 (BU), Harness Side And Ground
      G06258874Courtesy of FORD MOTOR CO.
    • Is the voltage greater than 10 volts? 
    • Yes  : GO to K5.
    • No  : VERIFY the SJB fuse 41 (15A) is OK. If OK, REPAIR the circuit for an open. TEST the system for normal operation. If not OK, REFER to the appropriate SYSTEM WIRING DIAGRAMS article, to identify the possible causes of the circuit short.
  5. K5 BYPASS THE AMBIENT LIGHTING SWITCH 
    • Connect and remove a fused jumper wire between the ambient lighting switch C2304-5, circuit CBP41 (BU), harness side and the ambient lighting switch C2304-4, circuit CLN54 (BN/YE), harness side.
      Fig 5: Connecting Fused Jumper Wire Between Ambient Lighting Switch C2304-5 And Ambient Lighting Switch C2304-4
      G06258875Courtesy of FORD MOTOR CO.
    • Do the ambient LEDs illuminate and cycle through a color change each time the jumper wire is connected and removed? 
  6. K6 CHECK FOR VOLTAGE TO THE AMBIENT LIGHTING MODULE USING THE CONNECTOR GROUND 
    • Measure the voltage between the ambient lighting module C3256-1, circuit CBX07 (GN/RD), harness side and the ambient lighting module C3256-8, circuit GD908 (BK), harness side.
      Fig 6: Measuring Voltage Between Ambient Lighting Module C3256-1, Circuit CBX07 (GN/RD) And Harness Side
      G06099284Courtesy of FORD MOTOR CO.
    • Is the voltage greater than 10 volts? 
    • Yes  : GO to K7.
    • No  : REPAIR the circuit for an open. TEST the system for normal operation.
  7. K7 CHECK THE AMBIENT LIGHTING HARNESS 
    • Ignition OFF.
    • Check any of the diode circuits between the ambient lighting module, harness side as follows:
      Connector-Pin/Circuit Connector-Pin/Circuit
      C3256-5 CLN45 (GN) C3256-4 RLN44 (BN)
      C3256-6 CLN46 (BU) C3256-4 RLN44 (BN)
      C3256-7 CLN44 (OG) C3256-4 RLN44 (BN)
      Fig 7: Checking Diode Circuits Between Ambient Lighting Module
      G06065412Courtesy of FORD MOTOR CO.
    • Does the meter indicate the circuit is good? 
    • Yes  : GO to K8.
    • No  : REPAIR or INSTALL a new ambient lighting harness. TEST the system for normal operation.
  8. K8 CHECK FOR CORRECT AMBIENT LIGHTING MODULE OPERATION 
    • Disconnect the ambient lighting module connector.
    • Check for:
      • corrosion
      • damaged pins
      • pushed-out pins
    • Connect the ambient lighting module connector and make sure it seats correctly.
    • Operate the system and verify the concern is still present.
    • Is the concern still present? 
    • Yes  : INSTALL a new ambient lighting module. REFER to AMBIENT LIGHTING MODULE  in this service information. TEST the system for normal operation.
    • 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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