Insufficient heating

Diagnostic Procedure 

• Check the engine coolant level
• Check the radiator cap
• Check the engine coolant temperature (ECT) during normal operation with the HDS
• Check the heater core inlet hose temperature:
• • If it is COLD, check for restrictions in the hose, a damaged or leaking thermostat, or a damaged or leaking water pump
  • If it is HOT, check for restrictions in the heater core. Back flush or replace the heater core
• Check the operation of the air mix doors:
• • Air mix control motor test*1
  • Driver's air mix control motor test*2
  • Passenger's air mix control motor test*2
• Check the blower motor unit for obstructions
• Check for air leaks around the ducts and vents

Also Check for 

Climate control DTCs