Chart 1 Insufficient or No Heating

%�LDiagnostic Chart:

A@�LDiagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION

Based on the various sensor assembly inputs input from the ECM and the set temperature the microprocessor determines the required temperature and delivery mode to achieve and maintain the selected comfort level.

Preliminary Inspection:

1. Check for proper engine coolant level.

2. Check engine for proper operating temperature (approximately 91°C (195°F)). If engine does not reach 91°C (105°F; replace thermostat assembly).

3. With engine at normal operating temperature check heater inlet and outlet hose temperature.

- Heater inlet hose temperature should be at or near engine operating temperature.

- Heater outlet hose temperature should be slightly cooler than the heater inlet hose.

- If heater hose temperatures are incorrect replace beater core.

4. Inspect plenum area (at base of windshield assembly) for debris or anything that may cause airflow restriction.