Pinpoint Test C: Climate Control System Functional Test

C1 CHECK THE PCM (POWERTRAIN CONTROL MODULE) FOR DIAGNOSTIC TROUBLE CODES (DTCS)
- Using a diagnostic scan tool, perform PCM and BCM self-tests.
Are any climate control related Diagnostic Trouble Codes (DTCs) present?
1. Yes : Refer to PCM DTC CHART in this service information.
2. No : GO to C2
C2 CHECK THE BCM (BODY CONTROL MODULE) FOR DIAGNOSTIC TROUBLE CODES (DTCS)
- Ignition ON.
- Using a diagnostic scan tool, perform BCM self-test.
Are any climate control related Diagnostic Trouble Codes (DTCs) present?
1. Yes : Refer to BCM DTC CHART in this service information.
2. No : GO to C3
C3 CHECK THE BLOWER MOTOR OPERATION
- Ignition ON.
- Select register mode.
- Observe blower motor operation and select each blower motor speed.
Does the blower motor operate in all selections and change speed in each?
1. Yes : GO to C4
2. No : If the blower motor does not operate in any setting, GO to PINPOINT TEST K
  If the blower motor does not correctly change speeds or turn off, GO to PINPOINT TEST L
C4 CHECK THE AIRFLOW OPERATION
- For correct airflow descriptions
  REFER to: CLIMATE CONTROL SYSTEM - VEHICLES WITH: ELECTRONIC MANUAL TEMPERATURE CONTROL (EMTC) - SYSTEM OPERATION AND COMPONENT DESCRIPTION .
- Select the highest blower motor setting.
- While observing the airflow, select each of the airflow positions (register, register/footwell, footwell, footwell/defrost, defrost).
Is the airflow directed to the correct outlets?
1. Yes : GO to C5
2. No : GO to PINPOINT TEST E
C5 CHECK THE RECIRCULATED AIR OPERATION
- Select register mode.
- Select the highest blower motor setting.
- Observe airflow noise.
- Press the recirculated air button (indicator on).
Does the airflow noise increase when the recirculated air mode is selected (indicator on)?
1. Yes : GO to C6
2. No : GO to PINPOINT TEST D
C6 VERIFY THE TEMPERATURE CONTROL OPERATION
- Start the vehicle and allow it to reach normal operating temperature.
- Make sure the A/C indicator is off. Press the button once if it is on.
- Select register mode.
- Change the temperature setting from the coldest to the warmest.
Does the temperature vary between significantly warmer than the ambient air temperature to ambient air temperature or cooler?
1. Yes : GO to C7
2. No : If the temperature does not get significantly warmer, GO to PINPOINT TEST F
  If the temperature does not change significantly, GO to PINPOINT TEST J
C7 VERIFY THE A/C (AIR CONDITIONING) COMPRESSOR CLUTCH DOES NOT ENGAGE WITH A/C (AIR CONDITIONING) OFF
- Set the temperature setting halfway between the coldest and warmest.
- Visually inspect A/C compressor clutch.
Is the A/C compressor clutch engaged?
1. Yes : GO to PINPOINT TEST I
2. No : GO to C8
C8 VERIFY THE A/C (AIR CONDITIONING) COMPRESSOR CLUTCH ENGAGEMENT IN THE A/C (AIR CONDITIONING) MODE
NOTE: If the A/C indicator does not turn on for this test, install a new HVAC control module.
- Make sure the ambient air temperature is above 2°C (36°F).
- Change the temperature setting to coldest (MAX A/C).
- Press the A/C button if the indicator is not on.
Does the A/C clutch engage when the A/C indicator is on?
1. Yes : GO to C9
2. No : If the A/C clutch engages but never cycles on/off, GO to PINPOINT TEST H
  If the A/C clutch never turns on, GO to PINPOINT TEST G
C9 CHECK FOR INSUFFICIENT COOLING
- Change the temperature setting to coldest (MAX A/C).
- Press the A/C button if the indicator is not on.
Does the A/C compressor clutch engage when the A/C indicator is on?
1. Yes : The system is operating correctly.
2. No : REFER to: REFRIGERANT SYSTEM TESTS .