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Problem Symptoms Table

WARNING: This page is about a different car, the 2004 Toyota 4Runner. However, it is still accessible from the selected car via links, so may be relevant.

If the normal code is displayed during DTC check although the problem still occurs, check the circuits for each problem symptom in the order given in the table below, and proceed to the relevant troubleshooting.

(*1): Limited grade only

PROBLEM SYMPTOMS TABLE - AIR CONDITIONING SYSTEM

Symptom Suspect Area
Whole functions of the A/C system does not operate.
  1. IG power source circuit
  2. Heater control power supply circuit
  3. Heater control panel communication circuit
Air Flow Control: No blower operation
  1. Heater relay circuit
  2. Blower motor circuit
  3. Heater control panel communication circuit
Air Flow Control: No blower control
  1. Blower motor circuit
Temperature Control: No cool air comes out
  1. Volume of refrigerant
  2. Drive belt tension
  3. Refrigerant pressure
  4. Compressor lock sensor circuit
  5. Compressor circuit
  6. Pressure switch circuit
  7. Air mix control servomotor circuit

    (Driver side)((1)

    (Passenger side)

  8. Air mix damper position sensor circuit

    (Driver side)((1)

    (Passenger side)

  9. Room temp, sensor circuit
  10. Ambient temp, sensor circuit
  11. Vehicle speed signal circuit
  12. Heater control panel communication circuit
Temperature Control: No warm air comes out
  1. Air mix control servomotor circuit

    (Driver side)((1)

    (Passenger side)

  2. Air mix damper position sensor circuit

    (Driver side)((1)

    (Passenger side)

  3. Ambient temp, sensor circuit
  4. Vehicle speed signal circuit
  5. Room temp, sensor circuit
  6. Evaporator temp, sensor circuit
  7. Heater control panel communication circuit
  8. Heater radiator
Temperature Control: Output air is warmer or cooler than the set temperature or response is slow.
  1. Room temp, sensor circuit
  2. Ambient temp, sensor circuit
  3. Vehicle speed signal circuit
  4. Solar sensor circuit

    (Driver side)((1)

    (Passenger side)

  5. Air mix damper position sensor circuit

    (Driver side)((1)

    (Passenger side)

  6. Air mix control servomotor circuit

    (Driver side)((1)

    (Passenger side)

  7. Engine coolant temperature communication circuit
  8. Heater control panel communication circuit
Temperature Control: No temperature control (only Max. cool or Max. warm)
  1. Air mix control servomotor circuit

    (Driver side)((1)

    (Passenger side)

  2. Air mix damper position sensor circuit

    (Driver side)((1)

    (Passenger side)

  3. Heater control panel communication circuit
No air inlet control
  1. Air inlet damper control servomotor circuit
  2. Air inlet damper position sensor circuit
  3. Heater control paxnel communication circuit
No air outlet control
  1. Air outlet damper position sensor circuit
  2. Air outlet control servomotor circuit
  3. Heater control panel communication circuit
Engine idle up does not occur, or is continuous
  1. Compressor circuit
  2. Heater control panel communication circuit
Set temperature value displayed does not much up with operation of temperature control switch.
  1. Heater control panel communication circuit
Brightness does not changes when rheostat volume or light control switch it turned.
  1. Illumination light system
  2. Heater control panel
Unable to access the diagnosis mode.
  1. Heater control panel communication circuit
DTC not recorded. Set mode is cleared when IG switch is turned off.
  1. Back-up power source circuit
  2. A/C amplifier
(1) Limited grade only
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