FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
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Pinpoint Test I: Unable to Duplicate the Customer Concern and No DTCs Present




Climate Control System

Pinpoint Test I: Unable to Duplicate the Customer Concern and No DTCs Present

Normal Operation

The purpose of this pinpoint test is to test the functions of the HVAC system and to identify the correct pinpoint test HVAC symptom.

This pinpoint test is intended to diagnose the following:

- Incorrect functioning of the HVAC system

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

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 the PCM DTC Chart. Heating and Air Conditioning

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 R. Pinpoint Test R: The Blower Motor is Inoperative

If the blower motor does not properly change speeds or shut OFF, GO to Pinpoint Test S. Pinpoint Test S: The Blower Motor Does Not Operate Correctly

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. Pinpoint Test K: Incorrect/Erratic Direction of Airflow From Outlets

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. Pinpoint Test L: Insufficient, Erratic or No Heat

For Electronic Manual Temperature Control (EMTC) systems, if the temperature does not change at all, GO to Pinpoint Test P. Pinpoint Test P: Temperature Control is Inoperative/Does Not Operate Correctly - EMTC (Electronic Manual Temperature Control)

For Dual Automatic Temperature Control (DATC) systems, if the temperature does not change at all, GO to Pinpoint Test Q. Pinpoint Test Q: Temperature Control is Inoperative/Does Not Operate Correctly - DATC (Dual Automatic Temperature Control) Syst

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

For EMTC (Electronic Manual Temperature Control) systems, if the temperature is warmer than ambient temperature, GO to Pinpoint Test P and diagnose for inoperative blend door. Pinpoint Test P: Temperature Control is Inoperative/Does Not Operate Correctly - EMTC (Electronic Manual Temperature Control)

For DATC (Dual Automatic Temperature Control) systems, if the temperature is warmer than ambient temperature, GO to Pinpoint Test Q and diagnose for inoperative blend door. Pinpoint Test Q: Temperature Control is Inoperative/Does Not Operate Correctly - DATC (Dual Automatic Temperature Control) Syst

If the outlet temperature is significantly colder than ambient temperature and the A/C compressor clutch cycles normally, GO to Pinpoint Test O. Pinpoint Test O: The Air Conditioning (A/C) is Always On - A/C Mode Always Commanded ON

If the outlet temperature is significantly colder than ambient temperature and the A/C compressor clutch does not cycle, GO to Pinpoint Test N. Pinpoint Test N: The Air Conditioning (A/C) is Always On - A/C Compressor Does Not Cycle

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. Pinpoint Test M: The Air Conditioning (A/C) is Inoperative

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
The system is operating normally.

No
GO to Pinpoint Test J. Pinpoint Test J: The Air Inlet Door is Inoperative