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Pinpoint Test G: The Audio Control Module (ACM) 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. G1 CHECK THE ACM C240c FOR DAMAGE 
    • Key in OFF position.
    • Disconnect: ACM C240c.
    • Inspect the ACM C240c for damage.
    • Is the ACM C240c OK? 

    Result / Action to Take 

    1. Yes  : GO to G2.
    2. No  : REPAIR the ACM C240c as necessary. TEST the system for normal operation.
  2. G2 CHECK FOR AN OPEN BETWEEN THE DLC C251 AND THE ACM 
    • Measure the resistance between the ACM C240c-3, circuit 4-EG10 (GY/BK), or ACM C290c-1, circuit 4-EG10 (GY/BK) DM1 00i only, harness side and the DLC C251-2, circuit 4-EG7 (GY/RD), harness side.
      Fig 1: Checking For Open Between DLC C251 And ACM (1 Of 2)
      G03202996Courtesy of FORD MOTOR CO.
    • Measure the resistance between the ACM C240c-4, circuit 5-EG10 (BU/YE), or ACM C290c-4, circuit 5-EG10 (BU/YE) DM1 00i only, harness side and the DLC C251 -10, circuit 5-EG7 (BU/RD), harness side.
      Fig 2: Checking For Open Between DLC C251 And ACM (2 Of 2)
      G03202997Courtesy of FORD MOTOR CO.
    • Are the resistances less than 5 ohms? 
    1. Yes  : GO to  G5.
    2. No  GO to G3.
  3. G3 CHECK FOR AN OPEN BETWEEN THE ACM AND JOINT CONNECTOR No. 4 C223 
    • Disconnect: Joint Connector No. 4 C223.
    • Measure the resistance between the ACM C240c-3, circuit 4-EG10 (GY/BK), or ACM C290c-1, circuit 4-EG10 (GY/BK) DM1 00i only, harness side and joint connector No. 4 C223-16, circuit 4-EG10 (GY/BK), harness side.
      Fig 3: Checking For Open Between ACM And Joint Connector No. 4 C223 (1 Of 2)
      G03202998Courtesy of FORD MOTOR CO.
    • Measure the resistance between the ACM C290c-4, circuit 5-EG10 (BU/YE), or ACM C290c-4, circuit 5-EG10 (BU/YE) DM1 00i only, harness side and joint connector No. 4 C223-7, circuit 5-EG10 (BU/YE), harness side.
      Fig 4: Checking For Open Between ACM And Joint Connector No. 4 C223 (2 Of 2)
      G03202999Courtesy of FORD MOTOR CO.
    • Are the resistances less than 5 ohms?
    1. Yes  : GO to G4.
    2. No  : REPAIR the circuit in question. TEST the system for normal operation.
  4. G4 CHECK JOINT CONNECTOR No. 4 FOR AN OPEN 
    • Measure the resistance between joint connector No. 4 C223-14, component side and joint connector No. 4 C223-16, component side.
      Fig 5: Checking Joint Connector No. 4 For An Open (1 Of 2)
      G03203000Courtesy of FORD MOTOR CO.
    • Measure the resistance between joint connector No. 4 C223-7, component side and joint connector No. 4 C223-9, component side.
      Fig 6: Checking Joint Connector No. 4 For An Open (2 Of 2)
      G03203001Courtesy 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.4C223. 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.
  5. G5 CHECK FOR CORRECT ACM OPERATION 
    • Disconnect all the ACM connectors.
    • Check for:
      • corrosion
      • push-out pins
    • Connect all the ACM 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 ACM. REFER to ENTERTAINMENT SYSTEM - LS . 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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