Tech Tips
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.
As the operation of the quick heater may be limited due to battery voltage reduction history in the power steering system, proceed according to "How to Proceed with Troubleshooting".*
Inspect the fuses and relays related to this system before inspecting the suspected areas below.
| Symptom | Suspected Area | See page |
|---|---|---|
| All functions of the A/C system do not operate | Proceed to "IG Power Source Circuit" | |
| Proceed to "Back-up Power Source Circuit"* | ||
| Proceed to "Heater Control Switch Circuit" | ||
| Replace air conditioning amplifier assembly | ||
| Air Flow Control: No blower operation | Proceed to "Blower Motor Circuit" | |
| Air Flow Control: No blower control | Proceed to "Blower Motor Circuit" | |
| Air Flow Control: Insufficient air flow | Proceed to "Blower Motor Circuit" | |
| Temperature Control: No cool air comes out | Check volume of refrigerant | |
| Check for refrigerant gas leak | ||
| Replace cooler expansion valve | ||
| Replace compressor assembly with pulley (for AD Series Engine) | ||
| Replace compressor assembly with pulley (for ZR Series Engine) | ||
| Proceed to "Pressure Sensor Circuit" | ||
| Proceed to "Compressor Solenoid Circuit" | ||
| Proceed to "Evaporator Temperature Sensor Circuit" | ||
| Proceed to "Ambient Temperature Sensor Circuit" | ||
| Check air mix damper control cable sub-assembly | ||
| Replace air conditioning amplifier assembly | ||
| Proceed to "CAN Communication System" | ||
| Temperature Control: No warm air comes out | Check air mix damper control cable sub-assembly | |
| Replace heater radiator unit sub-assembly | ||
| Temperature Control: Output air is warmer or cooler than the set temperature or response is slow | Check volume of refrigerant | |
| Check for refrigerant gas leak | ||
| Replace cooler expansion valve | ||
| Replace compressor assembly with pulley (for AD Series Engine) | ||
| Replace compressor assembly with pulley (for ZR Series Engine) | ||
| Replace heater radiator unit sub-assembly | ||
| Proceed to "Ambient Temperature Sensor Circuit" | ||
| Check air mix damper control cable sub-assembly | ||
| No air inlet control | Proceed to "Recirculation Damper Servo Motor Circuit" | |
| Check heater control base sub-assembly (air inlet control switch) | ||
| No air flow mode control | Check No. 2 heater control cable sub-assembly | |
| Engine idle up does not occur or is continuous | Proceed to "Compressor Solenoid Circuit" | |
| Replace air conditioning amplifier assembly | ||
| Replace ECM (for 1ZR-FAE) | ||
| Replace ECM (for 2ZR-FAE) | ||
| Replace ECM (for 1AD-FTV) | ||
| Replace ECM (for 2AD-FHV) | ||
| Proceed to "CAN Communication System" | ||
| Blinking of air conditioning switch indicator | Proceed to "Heater Control Switch Circuit" | |
| Replace air conditioning amplifier assembly | ||
| Diagnostic trouble codes are not stored, and set mode is cleared when ignition switch is off | Proceed to "Back-up Power Source Circuit"* | |
| Replace air conditioning amplifier assembly | ||
| Engine coolant does not warm up quickly when the engine is cold (PTC heater does not operate)* | Proceed to "PTC Heater Circuit" | |
| Proceed to "Generator Signal Circuit" | ||
| Check generator assembly (for 1ZR-FAE) | ||
| Check generator assembly (for 2ZR-FAE) | ||
| Check generator assembly (for 1AD-FTV) | ||
| Check generator assembly (for 2AD-FHV) | ||
| Proceed to "Headlight Signal Circuit" | ||
| Replace air conditioning amplifier assembly | ||
| Rear window defogger, quick heater and mirror heater do not operate* | Power steering system (battery voltage reduction history) |
*: w/ PTC heater