Toyota Yaris: Air Conditioning System / Ambient Temperature Display System

• When the vehicle is stopped or being driven at low speeds, the displayed ambient temperature will not be updated to a higher temperature to adjust for and minimize the influence of radiant heat from the engine room on the automatic air conditioning system control. When the vehicle is not being driven at low speeds, the adjustment is performed, but updating of the displayed ambient temperature to a higher temperature is delayed. The displayed ambient temperature will be updated to a lower temperature regardless of the vehicle speed.
• When the ambient temperature around the thermistor assembly suddenly changes due to any reason other than radiant heat from the engine room, such as when the vehicle enters or exits a garage or tunnel, the actual ambient temperature of the vehicle and the displayed ambient temperature may differ or changing of the displayed value may be delayed.

NOTICE:

• Before starting the inspection, it is necessary to release the residual heat from the engine room (engine unit and coolant hoses, etc.) after stopping the engine and electric motor (when the vehicle is parked after being driven). Therefore, move and park the vehicle in the following type of temperature measurement location.
  • A location within the vehicle service area which has a relatively low amount of environmental temperature changes in the area surrounding the vehicle.
  • A location with a level surface made of a material such as concrete which transmits a relatively low amount of heat from the ground, such as concrete.
  • A location with no heat influences around the vehicle to be inspected such as other vehicles with a running engine and electric motors, exhaust gas ducts installed on the exhaust pipes, stoves, etc.
• The air conditioning system uses the CAN communication system. Inspect the communication function by following How to Proceed with Troubleshooting. Troubleshoot the air conditioning system after confirming that the communication system is functioning properly.

  Click here

• After turning the ignition switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal.

  Click here

  HINT:

  When disconnecting and reconnecting the cable to the auxiliary battery terminal, there is an automatic learning function that completes learning when the respective system is used.

  Click here

NOTICE:

• Perform the following procedure with the ignition switch to ON.
• Wait at least 6 minutes for the values of the thermistor assembly and thermometer to become stable before taking a measurement.
• Hold the thermometer 50 mm (1.97 in.) from the thermistor assembly with its sensing portion at the same height and perpendicular to the thermistor assembly.
• Hold the sensor only by its connector. Touching the sensing portion may change the resistance value.
• When measuring the ambient temperature with a thermometer, do not move the thermometer, touch the sensing portion or allow it to contact the vehicle body.

Blower Motor Circuit

DESCRIPTION The blower motor with fan sub-assembly is operated by signals from the air conditioning amplifier assembly. Blower motor speed signals are transmitted in accordance with changes in the duty ratio...

A/C Switch Indicator does not Turn On

DESCRIPTION If none of the switch indicators on the air conditioning control assembly illuminate, the following factors may be the cause. Symptom Factor A/C switch indicator does not illuminate Vehicle control history (RoB) Air conditioning amplifier assembly malfunction Air conditioning control assembly malfunction A/C switch malfunction A/C switch indicator malfunction (including when indicator turned off without switch operation) Servo motor initialization (incomplete) Mechanical locking of damper and damper link Refrigerant pressure is extremely low Low detected ambient temperature (including thermistor assembly malfunction) PROCEDURE 1...

Other information:

Toyota Yaris XP210 (2020-2025) Reapir and Service Manual: On-vehicle Inspection

ON-VEHICLE INSPECTION CAUTION / NOTICE / HINT CAUTION: To prevent injury due to contact with an operating V-ribbed belt or cooling fan, keep your hands and clothing away from the V-ribbed belt and cooling fan when working in the engine compartment with the engine running or the ignition switch on (IG)...

Toyota Yaris XP210 (2020-2025) Reapir and Service Manual: Problem Symptoms Table

PROBLEM SYMPTOMS TABLE HINT: 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...