Heater Performance: Notes

See COOLING SYSTEM when performing the following checks:

• Check the engine coolant level and flow
• Check engine coolant reserve/recovery system operation
• Check accessory drive belt condition and tension
• Check radiator air flow and the fan drive operation

Perform the A/C System Performance Test, which is found within Heating, Ventilation and Air Conditioning (HVAC) System Diagnosis and Testing. Refer to DIAGNOSIS AND TESTING . If any Diagnostic Trouble Codes (DTCs) are found, repair as necessary (Refer to DTC INDEX ).

If engine has been operated recently, wait 15 minutes before removing the radiator cap. Place a rag over the cap and turn it to the first safety stop. Allow pressure to escape through the overflow tube. When the system pressure stabilizes, remove the cap completely.