Control System (HVAC): Diagnosis Mazda MX-5 NC

EVAPORATOR TEMPERATURE SENSOR INSPECTION

Note. Inspect the evaporator temperature sensor when it is installed to the A/C unit.

Scheme 30

1. Set the fan speed MAX-HI.
2. Set the temperature control to MAX COLD.
3. Set the air intake mode to RECIRCULATE.
4. Turn the A/C switch off.
5. Close all of the doors and roll up all the windows.
6. Wait for 5 min.
7. Disconnect the evaporator temperature sensor connector.
8. Measure the temperature at the air intake.
9. Measure the resistance between evaporator temperature sensor terminals. If the characteristics of the evaporator temperature sensor are not (Scheme 30), replace the evaporator temperature sensor.

Scheme 31

1. Remove the battery cover.
2. Disconnect the negative battery cable. (See «BATTERY REMOVAL/INSTALLATION [LF]»(ref-244448-S25513985422006092400000).)
3. Discharge the refrigerant from the system. (See «REFRIGERANT CHARGING»(ref-244471-S09026287512006092400000).)
4. Remove in the order indicated in (Scheme 31).
5. Install in the reverse order of removal.

CLIMATE CONTROL UNIT INSPECTION

1. Turn the ignition switch to the ON position.
2. Connect the negative (-) lead of the tester to body ground.
3. By inserting the positive (+) lead of the tester into each climate control unit terminal, measure the voltage according to «TERMINAL VOLTAGE REFERENCE TABLE»(ref-244473-S00179116702006092400000) . If there is any malfunction, inspect the parts under "Inspection item (s)". If the parts under "Inspection item (s)" are found to be normal, replace the climate control unit.

Scheme 32

TERMINAL VOLTAGE REFERENCE TABLE

Scheme 33