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Pinpoint Test Ab: U3003:16

WARNING: This page is about a different car, the 2023 Ford Bronco. However, it is still accessible from the selected car via links, so may be relevant.
  1. Refer to AUTOMATIC CLIMATE CONTROL SYSTEM for schematic and connector information.

    Normal Operation and Fault Conditions 

    The modules monitor the supplied voltage and set a DTC if it falls below a threshold.

    DTC Fault Trigger Conditions 

    DTC Description Fault Trigger Condition
    HVAC U3003:16 Battery Voltage: Circuit Voltage Below Threshold HVAC control module senses lower than expected system voltage.

    Possible Sources 

    • Wiring, terminals or connectors
    • Charging system concern
    • Low battery
    • HVAC control module

  2. AB1 RECHECK FOR LOW VOLTAGE DIAGNOSTIC TROUBLE CODES (DTCS)

    • Ignition ON.

    • Using a diagnostic scan tool, clear the Diagnostic Trouble Codes (DTCs) for the HVAC control module setting the low voltage DTC.

    • Wait 10 seconds.

    • Using a diagnostic scan tool, carry out the self-test for the HVAC control module setting the low voltage DTC.

    Is DTC U3003:16 still present? 

    Yes  GO to  AB2
    No  The system is operating correctly at this time. The DTC may have been set due to a previous low battery voltage condition.

  3. AB2 CHECK FOR CHARGING SYSTEM DIAGNOSTIC TROUBLE CODES (DTCS)

    • Using a diagnostic scan tool, carry out the PCMKOEO and KOER self-tests.

    Are any voltage-related Diagnostic Trouble Codes (DTCs) present? 

    Yes  DIAGNOSE the charging system concern. REFER to: Charging System - 2.3L EcoBoost (199kW/270PS) . REFER to: Charging System - 2.7L EcoBoost (238kW/324PS) .
    No  GO to  AB3

  4. AB3 CHECK THE BATTERY CONDITION AND STATE OF CHARGE

    • Ignition OFF.

    • Check the battery condition and verify the battery is fully charged. REFER to: Battery .

    Is the battery OK and fully charged? 

    Yes  GO to  AB4
    No  DIAGNOSE the battery. REFER to: Battery .

  5. AB4 COMPARE THE SUSPECT MODULE VOLTAGE SUPPLY PID (PARAMETER IDENTIFICATION) TO THE BATTERY VOLTAGE

    • Ignition ON.

    • Measure and record the battery voltage.

    For the suspect module, monitor the voltage supply PID :

    • Access the HVAC and monitor the VPWR (V) PID

    Is the voltage reading within 0.2 volt of the recorded battery voltage? 

    Yes  For the HVAC control module, GO to  AB7
    No  GO to  AB5

  6. AB5 CHECK THE MODULE VOLTAGE SUPPLY CIRCUIT FOR HIGH RESISTANCE

    • Ignition OFF.

    • Ignition ON.

    • Measure and record the battery voltage.

    • Measure:

      HVAC control module 

      Positive Lead Measurement / Action Negative Lead
      C228A Pin 26
      GFD758227Courtesy of FORD MOTOR COMPANY
      		 Ground

    Is the voltage reading within 0.2 volt of the recorded battery voltage? 

    Yes  GO to  AB6
    No  REPAIR the circuit for high resistance.

  7. AB6 CHECK THE SUSPECT MODULE GROUND CIRCUIT FOR HIGH RESISTANCE

    • Measure:

      HVAC control module 

      Positive Lead Measurement / Action Negative Lead
      C228A Pin 26
      GFD758227Courtesy of FORD MOTOR COMPANY
      		 C228A Pin 1

    Is the voltage reading within 0.2 volt of the recorded battery voltage? 

    Yes  For the HVAC control module, GO to  AB7
    No  REPAIR the circuit for high resistance.

  8. AB7 CHECK FOR CORRECT HVAC (HEATING, VENTILATION AND AIR CONDITIONING) CONTROL MODULE OPERATION

    • Ignition OFF.

    • Disconnect and inspect all HVAC control module electrical connectors.

    • Repair:

      • corrosion (install new connector or terminal - clean module pins)
      • damaged or bent pins - install new terminals or pins
      • pushed-out pins - install new pins as necessary

    • Connect all HVAC control module electrical connectors. Make sure they seat and latch correctly. WAIT 20 seconds for the range calibration to be executed after reconnecting of the module before any further assessment or measurement is made. If the actuator range calibration does not start, or has been interrupted, carry out the HVAC Calibration Routine, using a diagnostic scan tool.

    • Operate the system and determine if the concern is still present.

    Is the concern still present? 

    Yes  CHECK OASIS for any applicable service articles: TSB, GSB, SSM or FSA. If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions. If no service articles address this concern, INSTALL a new HVAC control module. REFER to: Heating, Ventilation and Air Conditioning (HVAC) Control Module .
    No  The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. ADDRESS the root cause of any connector or pin issues.
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