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Home >> Lincoln >> 2012 >> MKZ Hybrid >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 12 (HVAC - Climate Control System - General Information And Diagnostics (Except Hybrid)) >> Diagnosis And Testing >> Climate Control System >> Pinpoint Tests >> Pinpoint Test I: Unable to Duplicate the Customer Concern and No DTCs Present >> PINPOINT TEST I: UNABLE TO DUPLICATE CUSTOMER CONCERN AND NO DTCs PRESENT

PINPOINT TEST I: UNABLE TO DUPLICATE CUSTOMER CONCERN AND NO DTCs PRESENT

WARNING: This page is about a different variant/trim than selected.
NOTE: Diagnose any HVAC module DTCs before carrying out the following pinpoint test.
NOTE: Some PCM DTCs may inhibit A/C operation. If any PCM DTCs are retrieved, diagnose those first. Refer to PCM DTC Chart .
  1. I1 CHECK THE BLOWER MOTOR OPERATION 
    • Ignition ON.
    • Select PANEL mode.
    • Observe blower motor operation and select each blower motor speed.
    • Does the blower motor operate in all selections and change speed in each? 
    • Yes:  GO to I2.
    • No:  For Electronic Manual Temperature Control (EMTC) systems, if the blower motor does not operate in any setting, GO to PINPOINT TEST Q .

      For Dual Automatic Temperature Control (DATC) systems, if the blower motor does not operate in any setting, GO to PINPOINT TEST S .

      For EMTC systems if the blower motor does not properly change speeds or shut OFF, GO to PINPOINT TEST R .

      For DATC systems if the blower motor does not properly change speeds or shut OFF, GO to PINPOINT TEST T .

  2. I2 CHECK AIRFLOW OPERATION 
    • Select the highest blower motor setting.
    • NOTE: Refer to DESCRIPTION AND OPERATION  for proper airflow descriptions.
    • While observing the airflow, select each of the airflow positions (PANEL, PANEL/FLOOR, FLOOR, FLOOR/DEFROST, DEFROST).
    • Is the airflow directed to the proper outlets? 
  3. I3 VERIFY TEMPERATURE CONTROL OPERATION 
    • Start the vehicle and allow it to reach normal operating temperature.
    • With the A/C OFF, select PANEL mode.
    • Change the temperature setting from the coldest to the warmest and back to the coldest.
    • Does the temperature change between very warm to cool? 
    • Yes:  GO to I4.
    • No:  If the temperature does not get very warm, GO to PINPOINT TEST L .

      If the temperature does not change at all, GO to PINPOINT TEST P .

  4. I4 VERIFY THE A/C CLUTCH DOES NOT ENGAGE WITH A/C OFF 
    • With the A/C OFF, select PANEL mode.
    • Select the coldest temperature setting.
    • Is the outlet temperature close to ambient temperature? 
    • Yes:  GO to I5.
    • No:  If the temperature is warmer than ambient temperature, GO to PINPOINT TEST P  and diagnose for inoperative blend door.

      If the outlet temperature is significantly colder than ambient temperature and the A/C compressor clutch cycles normally, GO to PINPOINT TEST O .

      If the outlet temperature is significantly colder than ambient temperature and the A/C compressor clutch does not cycle, GO to PINPOINT TEST N .

  5. I5 VERIFY A/C CLUTCH ENGAGEMENT IN THE A/C MODE 
    • Make sure the ambient air temperature is above 2°C (35°F).
    • Select PANEL mode.
    • Press the A/C button (indicator ON).
    • Does the A/C clutch engage when the PANEL and A/C button (indicator ON) is pressed? 
  6. I6 CHECK THE RECIRC OPERATION 
    • Press the RECIRC button (indicator OFF).
    • Select PANEL mode.
    • Select the highest blower motor setting.
    • Observe airflow noise.
    • Press the RECIRC button (indicator ON).
    • Does the airflow noise increase when the RECIRC mode is selected (indicator ON)?