Tech Tips
If the battery voltage is low, the PTC heater may not operate. Refer to Data List for the power steering system (w/ PTC Heater).
Use the table below to help determine the cause of problem symptoms. If multiple suspected areas are listed, 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.
| Symptom | Suspected Area | Link |
|---|---|---|
| All functions of the air conditioning system do not operate | IG power source circuit | |
| Back-up power source circuit | ||
| LIN communication circuit | ||
| Air conditioning amplifier assembly | ||
| Air flow Control: No blower operation | Blower motor circuit | |
| LIN communication circuit | ||
| Air conditioning amplifier assembly | ||
| Air flow control: No blower control | Blower motor circuit | |
| LIN communication circuit | ||
| Air conditioning amplifier assembly | ||
| Air flow control: Insufficient air flow | Blower motor circuit | |
| Air conditioning amplifier assembly | ||
| Temperature control: No cool air comes out*4 | Refrigerant volume | - |
| Refrigerant pressure*2 | ||
| Refrigerant pressure*3 | ||
| Air conditioner pressure sensor circuit | ||
| LIN communication circuit | ||
| Air mix damper control servo motor circuit (upper air mix) | ||
| Air mix damper control servo motor circuit (lower air mix) | ||
| Evaporator temperature sensor circuit | ||
| Ambient temperature sensor circuit | ||
| Cooler expansion valve | ||
| No. 1 air conditioning radiator damper servo sub-assembly (upper air mix) | ||
| No. 1 air conditioning radiator damper servo sub-assembly (lower air mix) | ||
| Air conditioning harness assembly (heater radiator unit sub-assembly) | ||
| Air conditioning harness assembly (blower assembly) | ||
| Compressor with pulley assembly | ||
| Air conditioning amplifier assembly | ||
| ECM | ||
| Temperature control: No warm air comes out | LIN communication circuit | |
| Air mix damper control servo motor circuit (upper air mix) | ||
| Air mix damper control servo motor circuit (lower air mix) | ||
| Evaporator temperature sensor circuit*4 | ||
| Ambient temperature sensor circuit | ||
| PTC heater circuit*1 | ||
| No. 1 air conditioning radiator damper servo sub-assembly (upper air mix) | ||
| No. 1 air conditioning radiator damper servo sub-assembly (lower air mix) | ||
| Air conditioning harness assembly (heater radiator unit sub-assembly) | ||
| Air conditioning harness assembly (blower assembly) | ||
| Air conditioning amplifier assembly | ||
| ECM | ||
| Temperature control: Output air is warmer or cooler than the set temperature or response is slow | Refrigerant volume | - |
| Refrigerant pressure*2 | ||
| Refrigerant pressure*3 | ||
| Ambient temperature sensor circuit | ||
| LIN communication circuit | ||
| Air mix damper control servo motor circuit (upper air mix) | ||
| Air mix damper control servo motor circuit (lower air mix) | ||
| Air inlet damper control servo motor circuit | ||
| PTC heater circuit*1 | ||
| Heater radiator unit sub-assembly | ||
| Cooler expansion valve*4 | ||
| Temperature control: Output air is warmer or cooler than the set temperature or response is slow | No. 1 air conditioning radiator damper servo sub-assembly (upper air mix) | |
| No. 1 air conditioning radiator damper servo sub-assembly (lower air mix) | ||
| No. 1 blower damper servo sub-assembly (fresh/recirculation) | ||
| Air conditioning harness assembly (heater radiator unit sub-assembly) | ||
| Air conditioning harness assembly (blower assembly) | ||
| Air conditioning amplifier assembly | ||
| ECM | ||
| Temperature control: No temperature control (only MAX COLD or MAX HOT) | LIN communication circuit | |
| Air mix damper control servo motor circuit (upper air mix) | ||
| Air mix damper control servo motor circuit (lower air mix) | ||
| Ambient temperature sensor circuit | ||
| Evaporator temperature sensor circuit*4 | ||
| No. 1 air conditioning radiator damper servo sub-assembly (upper air mix) | ||
| No. 1 air conditioning radiator damper servo sub-assembly (lower air mix) | ||
| Air conditioning harness assembly (heater radiator unit sub-assembly) | ||
| Air conditioning harness assembly (blower assembly) | ||
| Air conditioning amplifier assembly | ||
| Temperature control: Output air temperature is different between left and right registers (the set temperature is the same for both) | Refrigerant volume | - |
| Refrigerant pressure*2 | ||
| Refrigerant pressure*3 | ||
| Air mix damper control servo motor circuit (upper air mix) | ||
| Air mix damper control servo motor circuit (lower air mix) | ||
| No. 1 air conditioning radiator damper servo sub-assembly (upper air mix) | ||
| No. 1 air conditioning radiator damper servo sub-assembly (lower air mix) | ||
| Air conditioning harness assembly (heater radiator unit sub-assembly) | ||
| Air conditioning harness assembly (blower assembly) | ||
| Air conditioning amplifier assembly | ||
| No air inlet control | LIN communication circuit | |
| Air inlet damper control servo motor circuit | ||
| No. 1 blower damper servo sub-assembly (fresh/recirculation) | ||
| Air conditioning harness assembly (heater radiator unit sub-assembly) | ||
| Air conditioning harness assembly (blower assembly) | ||
| Air conditioning amplifier assembly | ||
| Quick heater assembly does not operate*1 | PTC heater circuit | |
| Air conditioning amplifier assembly | ||
| Diagnostic trouble codes (DTCs) are not recorded. Set mode is cleared when the ignition switch is turned off | Back-up power source circuit | |
| Air conditioning amplifier assembly |
*1: w/ PTC Heater
*2: for HFC-134a (R134a)
*3: for HFO-1234yf (R1234yf)
*4: w/ Cooler System