LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 1380 (Heating, Ventilation And Air Conditioning) >> Diagnostic Information and Procedures >> Heating Performance Diagnostic

Heating Performance Diagnostic

WARNING: This page is about a different car, the 2004 Pontiac Vibe. However, it is still accessible from the selected car via links, so may be relevant.
Heating Performance Diagnostic

Step Action Yes No
1 Did you review air delivery description and operation and air temperature description and operation ? Go to Step 2  Go to Air Delivery Description and Operation and Air Temperature Description and Operation in HVAC Systems - Manual
2
  1. Start the engine.
  2. Allow the engine to idle.
Does the engine reach a normal operating temperature?		 Go to Step 3  Go to Step 9 
3
    CAUTION: Refer to Moving Parts and Hot Surfaces Caution in Cautions and Notices.
  1. Allow to idle.
  2. Select the FLOOR mode.
  3. Select the minimum blower speed.
  4. Select the maximum temperature setting.
  5. Feel the temperature of the inlet and outlet hoses at the heater core.
Does the inlet hose feel warmer than the outlet hose?		 Go to Step 7  Go to Step 4 
4
  1. Install a thermometer into the I/P center air outlet.
  2. Secure a thermometer to the heater core outlet hose.
  3. Select the VENT mode.
  4. Select the maximum blower speed.
  5. Select the maximum temperature setting.
  6. Record the temperature at the following locations:
    • The I/P center air outlet
    • The heater core outlet hose
  7. Compare the recorded temperatures.
Are the temperatures similar?		 Go to Step 5  Go to Step 6 
5
  1. Inspect and repair the following areas of the vehicle for cold air leaks:
    • The cowl
    • The recirculation door
    • The HVAC module case
  2. Perform the necessary repairs.
Are the repairs complete?		 Go to Step 10  -
6
  1. Inspect the temperature door operation. Refer to Temperature Control Cable Adjustment .
  2. Perform any necessary repairs.
Are the repairs complete?		 Go to Step 10  -
7
  1. Turn OFF the engine.
  2. Backflush the heater core. Refer to Flushing .
  3. Start the engine.
  4. Select the FLOOR mode.
  5. Select the minimum blower speed.
  6. Select the maximum temperature setting.
  7. Feel the temperature of the inlet and outlet hoses at the heater core.
Does the inlet hose feel warmer than the outlet hose?		 Go to Step 8  Go to Step 10 
8 Replace the heater core. Refer to Heater Core Replacement .
Is the repair complete?		 Go to Step 10  -
9 Repair the low engine temperature concern. Refer to Engine Fails To Reach Normal Operating Temperature in Engine Cooling.
Is the repair complete?		 Go to Step 10  -
10 Operate the system in order to verify the repair.
Does the system operate correctly?		 System OK Go to Step 2 
scientia non olet · About LEMON Manuals