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Pinpoint Test K: The Rear Electronic Module (Rem) 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. K1 CHECK THE REM C420b FOR DAMAGE 
    • Key in OFF position.
    • Disconnect: REM C420b.
    • Inspect the REM C420b for damage.
    • Is the REM C420b OK? 

    Result / Action to Take 

    1. Yes  : GO to K2.
    2. No  : REPAIR the REM C420b as necessary. TEST the system for normal operation.
  2. K2 CHECK FOR AN OPEN BETWEEN THE DLC C251 AND THE REM C420b 
    • Measure the resistance between the REM C420b-1, circuit 4-EG12 (GY/WH), harness side and the DLC C251 -2, circuit 4-EG7 (GY/RD), harness side.
      Fig 1: Checking For Open Between DLC C251 And REM C420B (1 Of 2)
      G03203024Courtesy of FORD MOTOR CO.
    • Measure the resistance between the REM C420b-2, circuit 5-EG12 (BU/OG), harness side and the DLC C251 -10, circuit 5-EG7 (BU/RD), harness side.
      Fig 2: Checking For Open Between DLC C251 And REM C420B (2 Of 2)
      G03203025Courtesy of FORD MOTOR CO.
    • Are the resistances less than 5 ohms? 
    1. Yes  : GO to  K7.
    2. No  : GO to K3.
  3. K3 CHECK FOR AN OPEN BETWEEN THE INTERIOR AJB C283b AND THE REM C420b 
    • Disconnect the interior AJB C283b.
    • Measure the resistance between the REM C420b-1, circuit 4-EG12 (GY/WH), harness side and the interior AJB C283b-16, circuit 4-EG12 (GY/WH), harness side.
      Fig 3: Checking For Open Between Interior AJB C283B And REM C420B (1 Of 2)
      G03203026Courtesy of FORD MOTOR CO.
    • Measure the resistance between the REM C420b-2, circuit 5-EG12 (BU/OG), harness side and the interior AJB C283b-12, circuit 5-EG12 (BU/OG), harness side.
      Fig 4: Checking For Open Between Interior AJB C283B And REM C420B (2 Of 2)
      G03203027Courtesy of FORD MOTOR CO.
    • Are the resistances less than 5 ohms? 
    1. Yes  : GO to K4.
    2. No  : REPAIR the circuit in question. TEST the system for normal operation.
  4. K4 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-16, component side.
      Fig 5: Checking For Open Between Interior AJB C283B And Interior AJB C283D (1 Of 2)
      G03203028Courtesy of FORD MOTOR CO.
    • Measure the resistance between the interior AJB C283d-12, component side and the interior AJB C283b-12, component side.
      Fig 6: Checking For Open Between Interior AJB C283B And Interior AJB C283D (2 Of 2)
      G03203029Courtesy of FORD MOTOR CO.
    • Are the resistances less than 5 ohms? 
    1. Yes  : GO to K5.
    2. No  : INSTALL a new interior AJB. TEST the system for normal operation.
  5. K5 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 7: Checking For Open Between Interior AJB C283D And Joint Connector No. 4 C223 (1 Of 2)
      G03203030Courtesy 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 8: Checking For Open Between Interior AJB C283D And Joint Connector No. 4 C223 (2 Of 2)
      G03203031Courtesy of FORD MOTOR CO.
    • Are the resistances less than 5 ohms? 
    1. Yes  : GO to K6.
    2. No  : REPAIR the circuit in question. CARRY OUT the PINPOINT TEST PC: data link diagnostics network test .
  6. K6 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 9: Checking Joint Connector No. 4 For An Open (1 Of 2)
      G03203032Courtesy 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 10: Checking Joint Connector No. 4 For An Open (2 Of 2)
      G03203033Courtesy 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.
  7. K7 CHECK FOR CORRECT REM OPERATION 
    • Disconnect all the REM connectors.
    • Check for:
      • corrosion
      • push-out pins
    • Connect all the REM 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 REM. REFER to REAR ELECTRONIC MODULE (REM) . 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.
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