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Home >> Mercury >> 2008 >> Milan Base, 3.0 1, FWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 84 (Charging System - General Information -- F250-F550 Super Duty) >> Diagnosis And Testing >> Charging System - Dual Generators >> Pinpoint Tests >> Pinpoint Test N: The Charging System Warning Indicator Flickers Or Is Intermittent

Pinpoint Test N: The Charging System Warning Indicator Flickers Or Is Intermittent

WARNING: This page is about a different car, the 2005 Ford Pickup, 2005 Ford F550 Super Duty, 2005 Ford F450 Super Duty, and 2005 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
  1. N1 CHECK THE DTCS IN THE PCM 
    • Key in OFF position.
    • Connect the diagnostic tool.
    • Key in ON position.
    • With the key ON, engine OFF, check the PCM for DTCs with the diagnostic tool.
    • Do generator DTCs exist? 
    • Yes  : GO to the appropriate pinpoint test listed in the Symptom Chart.
    • No  : GO to N2.
  2. N2 CHECK THE BATTERY VOLTAGE 
    • Key in START position.
    • With the key ON, engine running, and all the accessories turned off, measure the voltage at the battery while varying the engine rpm.
      Fig 1: Measuring Battery Voltage
      G03879700Courtesy of FORD MOTOR CO.
    • Is the voltage greater than 15.5 volts? 
  3. N3 CHECK THE CHARGING SYSTEM INDICATOR OPERATION 
    • Key in OFF position.
    • Enter the following diagnostic mode on the diagnostic tool: Active Commands.
    • Key in ON position.
    • With the key ON, engine OFF, enter the following diagnostic mode on the diagnostic tool: Active Commands. Command the charging system warning indicator on.
    • Does the charging system warning indicator illuminate? 
  4. N4 CHECK THE PCM OPERATION 
    • Key in OFF position.
    • Disconnect the diagnostic tool.
    • Key in ON position.

      With the key ON, engine OFF, monitor the charging system warning indicator.

    • Is the lamp illuminated? 
    • Yes  : PCM is operating correctly. RECHECK generator circuits (including generators) for intermittent shorts or opens. TEST the system for normal operation.
    • No  : GO to N5.
  5. N5 CHECK FOR CORRECT PCM OPERATION 
    • Disconnect all the PCM connectors.
    • Check for:
      • corrosion
      • pushed-out pins
    • Connect all the PCM connectors and make sure they seat correctly.
    • Operate the system and verify the concern is still present.
    • Is the concern still present? 
    • Yes  : INSTALL a new PCM. REFER to ELECTRONIC ENGINE CONTROLS - DIESEL ENGINE . CLEAR the DTCs. REPEAT the self-test. 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. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.