Tech Tips
Use the table below to help determine the cause of the problem symptom. The potential causes of the symptoms are listed in order of probability in the "Suspected Area" column of the table. Check each symptom by checking the suspected areas in the order they are listed. Replace parts as necessary.
Inspect the fuses and relays related to this system before inspecting the suspected areas below.
If the malfunction still exists even after checking and confirming that all the circuits are normal, replace the Air conditioning amplifier.
| Symptom | Suspected Area | See page |
|---|---|---|
| All functions of Air conditioning system do not operate | Air conditioning control assembly | |
| Air conditioning amplifier assembly | ||
| Wire harness | - | |
| Air flow control: No blower operation | Blower resistor | |
| Blower w/fan motor sub-assembly | ||
| Air conditioning control assembly | ||
| Wire Harness | - | |
| Air flow control: No blower control | Blower resistor | |
| Air conditioning control assembly | ||
| Wire Harness | - | |
| Air flow control: Insufficient air comes out | Blower w/fan motor sub-assembly | |
| Blower resistor | ||
| Air conditioning control assembly | ||
| Wire Harness | - | |
| Temperature control: No cool air comes out | Volume of refrigerant | |
| Drive belt | ||
| Refrigerant pressure | ||
| Magnet clutch assembly | ||
| Cooler compressor assembly | ||
| Magnet clutch relay | ||
| Air conditioner pressure switch | ||
| Air mix control cable | - | |
| Air conditioning control assembly | ||
| Wire Harness | - | |
| Temperature control: Output air is warmer or cooler than set temperature or response is slow | Air mix control cable | - |
| Air conditioning control assembly | ||
| Temperature control: No temperature control | Air mix control cable | - |
| Air conditioning control assembly | ||
| No air inlet control | Air inlet damper control cable | - |
| Air conditioning control assembly | ||
| No air outlet control | Mode control cable | - |
| Air conditioning control assembly | ||
| Engine idle-up does not occur, or is continuous | Magnet clutch assembly | |
| Cooler compressor assembly | ||
| Air conditioning control assembly | ||
| Air conditioning amplifier assembly | ||
| ECM |
| Symptom | Suspected Area | See page |
|---|---|---|
| PCT heater does not operate, in these conditions: Engine coolant temp: 65°C (149°F) or below, engine rpm is at idle rpm or more, temperature control knob: MAX HOT | PTC heater relay | |
| Heater switch assembly | ||
| Air mix control cable | - | |
| Air conditioning control assembly | ||
| Air conditioning unit assembly (Max. HOT switch) | ||
| Air conditioning amplifier assembly | ||
| ECM | ||
| Wire Harness | - | |
| Quick heater and accessory assembly |
| Symptom | Suspected Area | See page |
|---|---|---|
| Hot gas heater does not operate, in these conditions: Engine coolant temp: 65°C (149°F) or below, engine rpm is at idle rpm or more, temperature control knob: MAX HOT | Volume of refrigerant | |
| Refrigerant pressure | ||
| Heater switch assembly | ||
| Hot gas heater magnet valve | ||
| Magnet clutch relay | ||
| Air conditioning amplifier assembly |
| Symptom | Suspected Area | See page |
|---|---|---|
| Viscous heater does not operate, in these conditions: Engine coolant temp: 65°C(149°F) or below, engine rpm or more, temperature control knob: MAX HOT | Viscous w/ magnet clutch heater assembly | |
| Heater switch assembly | ||
| Heater radiator unit sub-assembly | - | |
| Heater amplifier assembly |