EATC/DATC Aspiration Test

This test will determine if the in-car temperature sensor is receiving enough aspiration. A lack of aspiration may result in an incorrect in-car temperature sensor reading and may cause the EATC/DATC system to act erratically and/or EATC/DATC blowing too cold or too warm.

1. Cut a piece of toilet tissue or tissue paper about 2.5 x 2.5 cm (1" x 1").

NOTE:
PAPER TOWEL WILL NOT WORK CORRECTLY.

2. Turn key on, fan speed to HIGH BLOWER, and select PANEL or VENT mode.

3. Place the piece of tissue paper over the aspirator grille opening. If aspiration (suction) is present, the tissue paper should stick to the grille.

4. Slowly lower the fan speed to LOW BLOWER. The tissue should continue sticking to the grille.

5. Turn the fan speed to HIGH BLOWER, then to OFF. Tissue paper should fall off the grille.

6. If the tissue paper falls off the aspirator grille when the blower fan is on in any speed:

a. Verify that the aspirator hose is properly connected at both ends. Check the aspirator hose for kinks or cuts.

b. Verify that the in-car temperature sensor is properly installed/sealed against the dash panel.

c. Repair as required.

7. On vehicles equipped with a coolant control valve, check for proper operation of the coolant control valve. Visually inspect vacuum hoses for kinks, leaks, or disconnects.

8. Temperature differentials between panel/floor/defrost vents in mix modes and temperature setpoints that are not at full cool or full heat may exist and are considered normal and not repairable.