Tech Tips
Use the table below to help determine the causes 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.
| Symptom | Suspected Area | See page |
|---|---|---|
| No functions of A/C panel operate | LIN communication line | |
| Air conditioning control assembly | - | |
| Air conditioning amplifier assembly | ||
| No functions of A/C system operate | IG power source circuit | |
| Back-up power source circuit | ||
| A/C fuse | - | |
| Air conditioning control assembly | - | |
| Air conditioning amplifier assembly | ||
| Wire harness or connector | - | |
| Airflow Control: No blower control (Blower motor does not operate) | HTR fuse | - |
| Blower motor circuit | ||
| Air conditioning amplifier assembly | ||
| Air conditioning control assembly | - | |
| Wire harness or connector | - | |
| Airflow Control: No blower control (Blower motor does not change speed) | Blower motor circuit | |
| Air conditioning amplifier assembly | ||
| Air conditioning control assembly | - | |
| Temperature Control: less cool air comes out | Refrigerant shortage check using the intelligent tester | |
| Refrigerant pressure | ||
| Expansion valve | ||
| Compressor and pulley (for 1ND-TV) | ||
| Compressor and pulley (for 1NR-FE) | ||
| Compressor and pulley (for 1NZ-FE) | ||
| Air conditioning amplifier assembly | ||
| Temperature Control: No cool air comes out | Refrigerant volume | |
| Refrigerant pressure | ||
| Air conditioner pressure sensor | ||
| Compressor and pulley (for 1ND-TV) | ||
| Compressor and pulley (for 1NR-FE) | ||
| Compressor and pulley (for 1NZ-FE) | ||
| Air mix damper control servo motor circuit | ||
| Evaporator temperature sensor circuit | ||
| Room temperature sensor circuit | ||
| Ambient temperature sensor circuit | ||
| Expansion valve | ||
| Air conditioning amplifier assembly | ||
| Air conditioning control assembly | - | |
| ECM (for 1ND-TV) | ||
| ECM (for 1NR-FE) | ||
| ECM (for 1NZ-FE) | ||
| LIN communication system | ||
| CAN communication system | ||
| Temperature Control: No warm air comes out | Air mix damper control servo motor circuit | |
| Air conditioning harness | - | |
| Room temperature sensor circuit | ||
| Ambient temperature sensor circuit | ||
| Air conditioning amplifier assembly | ||
| Air conditioning control assembly | - | |
| ECM (for 1ND-TV) | ||
| ECM (for 1NR-FE) | ||
| ECM (for 1NZ-FE) | ||
| PTC heater circuit* | ||
| LIN communication system | ||
| CAN communication system | ||
| Temperature Control: Output air is warmer or cooler than set temperature | Room temperature sensor circuit | |
| Ambient temperature sensor circuit | ||
| Air inlet damper control servo motor circuit | ||
| Heater radiator | - | |
| Expansion valve | - | |
| Air conditioning amplifier | ||
| Air conditioning control assembly | - | |
| ECM (for 1ND-TV) | ||
| ECM (for 1NR-FE) | ||
| ECM (for 1NZ-FE) | ||
| LIN communication system | ||
| CAN communication system | ||
| Temperature Control: No temperature control (Only Max. cool or Max. warm) | Automatic light control sensor | |
| Air conditioning amplifier assembly | ||
| Air conditioning control assembly | - | |
| LIN communication system | ||
| No air inlet control | Air conditioning control assembly | - |
| Air inlet damper control servo motor circuit | ||
| Evaporator temperature sensor circuit | ||
| Air conditioning amplifier assembly | ||
| Diagnostic trouble codes are not recorded. Set mode is cleared when ignition switch turned off. | Air conditioning amplifier assembly | |
| Back-up power source circuit |
*: w/ Quick Heater Assembly