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Home >> Ford >> 2005 >> Escape Base, 2.3 Z, FWD, Automatic >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Controls - Pinpoint Test NB: Malfunction Indicator Lamp Through Pinpoint Test Z: Intermittent - (Except Diesel & Hybrid) >> Pinpoint Test QA: Unable to Activate Self-Test/Network Communication Error >> Test Procedure
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Test Procedure

  1. QA1 CARRY OUT A VEHICLE INSPECTION AND VERIFY THE SELF-TEST PROCEDURE 
    NOTE: If the self-test or communication concern occurred after a failed or an aborted reprogram, the module may be blank. Attempt to reprogram the module again before continuing with this pinpoint.
    • This pinpoint test addresses the following concerns:
      • unable to communicate with PCM.
      • unable to activate the PCM self-test.
    • Possible causes:
      • incorrect self-test procedure.
      • communication circuit open from PCM to the DLC.
      • PCM power or ground circuits PCM.
      • VREF circuit short to ground (Excursion, Explorer Sport Trac, Ford GT, Freestar/Monterey, or Ranger).
    • Visually inspect the following for obvious signs of electrical damage:
      • harness wiring.
      • electrical connections.
    • Verify the correct procedure was used to activate the self-test for the diagnostic tool. REFER to DIAGNOSTIC TOOL SETUP AND FUNCTIONALITY .

    Was the correct self-test procedure used? 

    Yes No
    GO to  QA2. REFER to DIAGNOSTIC TOOL SETUP AND FUNCTIONALITY .
  2. QA2 CARRY OUT THE DATA LINK DIAGNOSTICS TEST 
    • Connect the diagnostic tool.
    • Key in ON position.
    • Carry out the data link diagnostics test.

    Is system passed obtained? 

    Yes No
    GO to QT1 CARRY OUT THE PCM QUICK TEST . For all electronic control units no response/not equipped, GO to  QA3.
    For PCM no response/not equipped, GO to  QA3.
    For no response from the diagnostic tool, REFER to MODULE COMMUNICATIONS NETWORK to diagnose no response from the diagnostic tool.
  3. QA3 CHECK FOR VREF VOLTAGE AT A SENSOR 
    NOTE: PCM power and ground can be determined by measuring VREF voltage at a sensor. Refer to the PCM COMMUNICATION PROTOCOL AND VREF INFORMATION TABLE  table at the beginning of this pinpoint test for the vehicle application and the applicable sensor to test.
    • Key in OFF position.
    • Disconnect the applicable sensor.
    • Key in ON position.
    • Measure the voltage between the applicable sensor VREF circuit, harness side and the applicable sensor SIGRTN circuit, harness side.

    Is the voltage between 4.5 volts - 5.5 volts? 

    Yes No
    For Excursion, Explorer Sport Trac, Ford GT, Freestar/Monterey, or Ranger, GO to  QA6.
    For all others, REFER to MODULE COMMUNICATIONS NETWORK to diagnose no communication with the PCM.    		 GO to  QA4.
  4. QA4 CHECK THE PCM VPWR CIRCUITS FOR VOLTAGE 
    • Key in OFF position.
    • Disconnect the PCM.
    • Key in ON position.
    • Measure the voltage between:
      (+) PCM Connector, Harness Side (-)
      VPWR Ground

    Are the voltages greater than 10.5 volts? 

    Yes No
    GO to  QA5. GO to B1 .
  5. QA5 CHECK THE PCM GROUND CIRCUITS FOR AN OPEN 
    • Key in OFF position.
    • Measure the resistance between:
      (+) PCM Connector, Harness Side (-)
      PWRGND Ground

    Are the resistances less than 5 ohms? 

    Yes No
    For Excursion, Explorer Sport Trac, Ford GT, Freestar/Monterey, or Ranger, GO to Pinpoint Test C step 1 .
    For all others, GO to  QA7.    		 REPAIR the open circuit.
  6. QA6 CHECK COMMUNICATION WITH THE SUSPECT SENSOR DISCONNECTED 
    • Key in ON position.
    • Carry out the data link diagnostics test.
    • Key in OFF position.
    • Reconnect the suspect sensor.
    • Carry out the data link diagnostics test.

    Is PCM communication present only when the sensor is disconnected? 

    Yes No
    INSTALL a new suspect sensor. REFER to MODULE COMMUNICATIONS NETWORK to diagnose no communication with the PCM.
  7. QA7 CHECK FOR CORRECT PCM OPERATION 
    • Disconnect all the PCM connectors.
    • Visually inspect for:
      • corrosion.
      • pushed out pins.
    • Connect all the PCM connectors and make sure they seat correctly.
    • Carry out the data link diagnostic test and verify the concern is still present.

    Is the concern still present? 

    Yes No
    INSTALL a new PCM. REFER to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) . The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector.
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