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

WARNING: This page is about a different car, the 2013 Ford Mustang. However, it is still accessible from the selected car via links, so may be relevant.

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 .

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 : If the blower motor does not operate in any setting, GO to PINPOINT TEST Q .
  If the blower motor does not properly change speeds or shut OFF, GO to PINPOINT TEST R .
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?
- Yes : GO to I3.
- No : GO to PINPOINT TEST K .
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 .
I4 VERIFY THE A/C CLUTCH DOES NOT ENGAGE WITH A/C OFF
- With the engine running and 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 .
I5 VERIFY A/C CLUTCH ENGAGEMENT IN THE A/C MODE
- Make sure the ambient air temperature is above 2°C (35°F).
- With the engine running, 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?
- Yes : GO to I6.
- No : GO to PINPOINT TEST M .
I6 CHECK THE RECIRC OPERATION
- With the engine running, 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)?
- Yes : For Electronic Manual Temperature Control (EMTC) equipped vehicles, the system is operating normally. For Dual Automatic Temperature Control (DATC) equipped vehicles, GO to I7.
- No : GO to PINPOINT TEST J .
I7 CHECK IN-VEHICLE TEMPERATURE SENSOR FAN OPERATION
- Make sure the ambient air temperature is above 2°C (35°F).
- With the engine running, select PANEL mode.
- Press the A/C button (indicator ON).
- Press the RECIRC button (indicator ON).
- Place a piece of tissue within 25 mm (1 in) of the in-vehicle temperature sensor opening.
- Is the tissue drawn to the sensor opening?
- Yes : The system is operating normally.
- No : GO to PINPOINT TEST S .