Pinpoint Test
- CHECK FOR CORRECT ENGINE COOLANT LEVEL
- Ignition OFF.
- Check the engine coolant level.
Is the engine coolant at the correct level as indicated on the engine coolant recovery reservoir?
- Yes: GO to 2 .
- No: REFER to DIAGNOSTIC ROUTINE A : Loss of Coolant.
- CHECK FOR COOLANT FLOW TO THE HEATER CORE
- Run the engine until it reaches normal operating temperature. Select the floor position. Set the temperature control to full warm and the blower to the lowest setting.
- Using a suitable temperature measuring device, check the heater core inlet hose to see if it is hot.
Is the heater core inlet hose temperature above 66 C (150 F)?
- Yes: GO to 3 .
- No: REFER to DIAGNOSTIC ROUTINE C : The Engine Does Not Reach Normal Operating Temperature.
- CHECK FOR A PLUGGED OR RESTRICTED HEATER CORE
- Using a suitable temperature measuring device, measure the heater core outlet hose temperature.
Is the heater core outlet hose temperature similar to the inlet hose temperature (within approximately 6 C (43 F) - 17 C (63 F))?
- Yes: For inadequate temperature out of the LH side, REFER to Diagnostic Routine P: The Temperature Control Is Inoperative or Does Not Operate Correctly - LH .
For inadequate temperature out of the RH side, REFER to Diagnostic Routine Q: The Temperature Control Is Inoperative or Does Not Operate Correctly - RH .
- No: INSTALL a new heater core. REFER to Heater Core .