Pinpoint Test B: HVAC Functions Verification
Climate Control System
Pinpoint Tests
Pinpoint Test B: HVAC Functions Verification
This pinpoint test is intended to diagnose the following:
- Incorrect functioning of the HVAC system
PINPOINT TEST B: HVAC FUNCTIONS VERIFICATION
NOTE: Some PCM DTCs may inhibit A/C operation. If any PCM DTCs are retrieved, diagnose those first. Refer to PCM DTC Chart. Diagnostic Trouble Code Tests and Associated Procedures
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B1 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 B2.
No
If the blower motor does not operate in any setting, Go To Pinpoint Test J. Pinpoint Test J: The Blower Motor Is Inoperative
If the blower motor does not properly change speeds or shut OFF, Go To Pinpoint Test K. Pinpoint Test K: The Blower Motor Does Not Operate Correctly
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B2 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 B3.
No
Go To Pinpoint Test C. Pinpoint Test C: Incorrect/Erratic Direction Of Airflow From Outlets
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B3 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 B4.
No
If the temperature does not get very warm, Go To Pinpoint Test K. Pinpoint Test K: The Blower Motor Does Not Operate Correctly
If the temperature does not change at all, Go To Pinpoint Test I. Pinpoint Test I: Temperature Control Is Inoperative/Does Not Operate Correctly
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B4 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 B5.
No
If the temperature is warmer than ambient temperature, Go To Pinpoint Test I and diagnose for inoperative blend door. Pinpoint Test I: Temperature Control Is Inoperative/Does Not Operate Correctly
If the outlet temperature is significantly colder than ambient temperature and the A/C compressor clutch cycles normally, Go To Pinpoint Test G. Pinpoint Test G: 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 F. Pinpoint Test F: The Air Conditioning (A/C) Is Always On - A/C Compressor Does Not Cycle
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B5 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?
Yes
GO to B6.
No
Go To Pinpoint Test E. Pinpoint Test E: The Air Conditioning (A/C) Is Inoperative
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B6 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)?
Yes
GO to B7.
No
Go To Pinpoint Test C. Pinpoint Test C: Incorrect/Erratic Direction Of Airflow From Outlets
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B7 CHECK THE AUXILIARY BLOWER MOTOR OPERATION
- Using the front and rear auxiliary blower motor controls, observe blower motor operation and select each auxiliary blower motor speed.
- Does the auxiliary blower motor operate in all selections and change speed in each?
Yes
GO to B8.
No
If the auxiliary blower motor does not operate in any setting, Go To Pinpoint Test L. Pinpoint Test L: The Auxiliary Blower Motor Is Inoperative
If the auxiliary blower motor does not properly change speeds or shut OFF, Go To Pinpoint Test M. Pinpoint Test M: The Auxiliary Blower Motor Does Not Operate Correctly
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B8 VERIFY AUXILIARY TEMPERATURE/MODE OPERATION
- Select the highest auxiliary blower motor setting.
- Using the front and rear auxiliary controls, change the temperature/mode setting from the coldest to the warmest/floor and back to the coldest/overhead.
- Does the temperature change between very warm to cool and auxiliary airflow to the floor when warm is selected and headliner when cool is selected?
Yes
The system is operating normally.
No
If both temperature and mode are affected, REPAIR the vacuum source line for an obstruction or leak. TEST the system for normal operation.
If the temperature or mode alone are affected, INSPECT the temperature or mode door for a binding or broken condition. If no condition is found, INSTALL a new actuator. TEST the system for normal operation.
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