LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lincoln >> 2003 >> LS 3.9 A >> Repair and Diagnosis >> External Pages >> Different car >> Section 286 (Module Communications Network) >> Diagnosis And Testing >> Communications Network >> Symptom Chart >> PINPOINT TEST L: The Navigation System Module Does Not Respond To The Diagnostic Tool >> Pinpoint Test L: The Navigation System Module Does Not Respond To The Diagnostic Tool
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Pinpoint Test L: The Navigation System Module Does Not Respond To The Diagnostic Tool

WARNING: This page is about a different car, the 2004 Lincoln LS. However, it is still accessible from the selected car via links, so may be relevant.

Test Step 

  1. L1 CHECK THE NAVIGATION SYSTEM MODULE C4209 FOR DAMAGE 
    • Key in OFF position.
    • Disconnect: Navigation System Module C4209.
    • Inspect the navigation system module C4209 for damage.
    • Is the navigation system module C4209 OK? 

    Result / Action to Take 

    1. Yes  : GO to L2.
    2. No  : REPAIR the navigation system module C4209 as necessary. TEST the system for normal operation.
  2. L2 CHECK FOR AN OPEN BETWEEN THE DLC C251 AND THE NAVIGATION SYSTEM MODULE C4209 
    • Measure the resistance between the navigation system module C4209-4, circuit 4-EG17 (GY/BK), harness side and the DLC C251 -2, circuit 4-EG7 (GY/RD), harness side.
      Fig 1: Checking For Open Between DLC C251 And Navigation System Module C4209 (1 Of 2)
      G03203034Courtesy of FORD MOTOR CO.
    • Measure the resistance between the navigation system module C4209-16, circuit 5-EG17 (BU/YE), harness side and the DLC C251-10, circuit 5-EG7 (BU/RD), harness side.
      Fig 2: Checking For Open Between DLC C251 And Navigation System Module C4209 (2 Of 2)
      G03203035Courtesy of FORD MOTOR CO.
    • Are the resistances less than 5 ohms? 
    1. Yes  : GO to  L9.
    2. No  : GO to L3.
  3. L3 CHECK FOR AN OPEN BETWEEN JOINT CONNECTOR No. 5 C427 AND THE NAVIGATION SYSTEM MODULE C4209 
    • Disconnect: Joint Connector No. 5 C427.
    • Measure the resistance between the navigation system module C4209-4, circuit 4-EG17 (GY/BK), harness side and joint connector No. 5 C427-4, circuit 4-EG17 (GY/BK), harness side.
      Fig 3: Checking For Open Between Joint Connector No. 5 C427 And Navigation System Module C4209 (1 Of 2)
      G03203036Courtesy of FORD MOTOR CO.
    • Measure the resistance between the navigation system module C4209-16, circuit 5-EG17 (BU/YE), harness side and joint connector No. 5 C427-15, circuit 5-EG17 (BU/YE), harness side.
      Fig 4: Checking For Open Between Joint Connector No. 5 C427 And Navigation System Module C4209 (2 Of 2)
      G03203037Courtesy of FORD MOTOR CO.
    • Are the resistances less than 5 ohms? 
    1. Yes  : GO to L4.
    2. No  : REPAIR the circuit in question. TEST the system for normal operation.
  4. L4 CHECK JOINT CONNECTOR No. 5 FOR AN OPEN 
    • Measure the resistance between joint connector No. 5 C427-1, component side and joint connector No. 5 C427-4, component side.
      Fig 5: Checking Joint Connector No. 5 For An Open (1 Of 2)
      G03203038Courtesy of FORD MOTOR CO.
    • Measure the resistance between joint connector No. 5 C427-12, component side and joint connector No. 5 C427-15, component side.
      Fig 6: Checking Joint Connector No. 5 For An Open (2 Of 2)
      G03203039Courtesy of FORD MOTOR CO.
    • Are the resistances less than 5 ohms? 
    1. Yes  : GO to L5.
    2. No  : REPAIR joint connector No. 5 C427 as necessary. TEST the system for normal operation.
  5. L5 CHECK FOR AN OPEN BETWEEN THE INTERIOR AJB C283b AND JOINT CONNECTOR No. 5 C427 
    • Disconnect: Interior AJB C283b.
    • Measure the resistance between the interior AJB C283b-8, circuit 4-EG1 (GY/RD), harness side and joint connector No. 5 C427-1, circuit 4-EG1 (GY/RD), harness side.
      Fig 7: Checking For Open Between Interior AJB C283B And Joint Connector No. 5 C427 (1 Of 2)
      G03203040Courtesy of FORD MOTOR CO.
    • Measure the resistance between the interior AJB C283b-4, circuit 5-EG1 (BU/RD), harness side and joint connector No. 5 C427-12, circuit 5-EG1 (BU/RD), harness side.
      Fig 8: Checking For Open Between Interior AJB C283B And Joint Connector No. 5 C427 (2 Of 2)
      G03203041Courtesy of FORD MOTOR CO.
    • Are the resistances less than 5 ohms? 
    1. Yes  : GO to L6.
    2. No  : REPAIR the circuit in question. CARRY OUT the PINPOINT TEST PC: data link diagnostics network test .
  6. L6 CHECK FOR AN OPEN BETWEEN THE INTERIOR AJB C283b AND THE INTERIOR AJB C283d 
    • Disconnect: Interior AJB C283d.
    • Measure the resistance between the interior AJB C283d-16, component side and the interior AJB C283b-8, component side.
      Fig 9: Checking For Open Between Interior AJB C283B And Interior AJB C283D (1 Of 2)
      G03203042Courtesy of FORD MOTOR CO.
    • Measure the resistance between the interior AJB C283d-12, component side and the interior AJB C283b-4, component side.
      Fig 10: Checking For Open Between Interior AJB C283B And Interior AJB C283D (2 Of 2)
      G03203043Courtesy of FORD MOTOR CO.
    • Are the resistances less than 5 ohms? 
    1. Yes  : GO to L7.
    2. No  : INSTALL a new interior AJB. TEST the system for normal operation.
  7. L7 CHECK FOR AN OPEN BETWEEN THE INTERIOR AJB C283d AND JOINT CONNECTOR No. 4 C223 
    • Disconnect: Interior Joint Connector No. 4 C223.
    • Measure the resistance between the interior AJB C283d-16, circuit 4-EG1 (GY/RD), harness side and joint connector No. 4 C223-12, circuit 4-EG1 (GY/RD), harness side.
      Fig 11: Checking For Open Between Interior AJB C283D And Joint Connector No. 4 C223 (1 Of 2)
      G03203044Courtesy of FORD MOTOR CO.
    • Measure the resistance between the interior AJB C283d-12, circuit 5-EG1 (BU/RD), harness side and joint connector No. 4 C223-11, circuit 5-EG1 (BU/RD), harness side.
      Fig 12: Checking For Open Between Interior AJB C283D And Joint Connector No. 4 C223 (2 Of 2)
      G03203045Courtesy of FORD MOTOR CO.
    • Are the resistances less than 5 ohms? 
    1. Yes  : GO to L8.
    2. No  : REPAIR the circuit in question. CARRY OUT the PINPOINT TEST PC: data link diagnostics network test .
  8. L8 CHECK JOINT CONNECTOR No. 4 FOR AN OPEN 
    • Measure the resistance between joint connector No. 4 C223-12, component side and joint connector No. 4 C223-14, component side.
      Fig 13: Checking Joint Connector No. 4 For An Open (1 Of 2)
      G03203046Courtesy of FORD MOTOR CO.
    • Measure the resistance between joint connector No. 4 C223-9, component side and joint connector No. 4 C223-11, component side.
      Fig 14: Checking Joint Connector No. 4 For An Open (2 Of 2)
      G03203047Courtesy of FORD MOTOR CO.
    • Are the resistances less than 5 ohms? 
    1. Yes  : REPAIR the circuit in question between the DLC C251 and joint connector No. 4 C223. CARRY OUT the PINPOINT TEST PC: data link diagnostics network test .
    2. No  : REPAIR joint connector No. 4 C223. TEST the system for normal operation.
  9. L9 CHECK FOR CORRECT NAVIGATION SYSTEM MODULE OPERATION 
    • Disconnect all the navigation system module connectors.
    • Check for:
      • corrosion
      • push-out pins
    • Connect all the navigation system module 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 navigation system module. REFER to ELECTRONIC FEATURE . TEST the system for normal operation.

      CARRY OUT the PINPOINT TEST PC: data link diagnostics network test .

    2. 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.
scientia non olet · About LEMON Manuals