Toyota Corolla Cross Owners & Service Manuals

Toyota Corolla Cross: A/C Inverter Cooling/Heating Over Temperature (B14744B)

Toyota Corolla Cross (2022-2024) Service Manual / Vehicle Interior / Heating / Air Conditioning / Air Conditioning System (for Hev Model) / A/C Inverter Cooling/Heating Over Temperature (B14744B)

DESCRIPTION

The temperature sensor of the compressor with motor assembly detects the A/C inverter temperature.

If the temperature exceeds the maximum, operation of the compressor with motor assembly will be stopped, and this DTC will be stored.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Memory

B14744B

A/C Inverter Cooling/Heating Over Temperature

Diagnosis Condition:

  • READY ON

Malfunction Status:

  • A/C inverter temperature outside specified range (temperature too high)

Detection Time:

  • None
  • Cooling fan system
  • Refrigerant volume
  • Compressor with motor assembly

Memorized

CAUTION / NOTICE / HINT

CAUTION:

  • Before inspecting the high-voltage system, take safety precautions such as wearing insulated gloves and removing the service plug grip to prevent electrical shocks. After removing the service plug grip, put it in your pocket to prevent other technicians from accidentally reconnecting it while you are working on the high-voltage system.

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  • Do not touch the high-voltage connectors or terminals for 10 minutes after the service plug grip is removed.

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NOTICE:

  • After turning the ignition switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work.

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  • When the cable is disconnected from the negative (-) auxiliary battery terminal, the memory of various systems will be cleared. Because of this, be sure to make a record of the contents memorized in each system before starting work. When work is finished, adjust each system to its previous state.
  • The hybrid control system and air conditioning system output DTCs separately. Perform troubleshooting for the hybrid control system first if DTCs for both systems are output simultaneously.

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  • The air conditioning system uses the CAN communication system. Inspect the communication functions by following How to Proceed with Troubleshooting. Troubleshoot the air conditioning system after confirming that the communication systems are functioning properly.

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PROCEDURE

1.

PERFORM ACTIVE TEST USING GTS

(a) Perform the Active Test according to the display on the GTS.

Powertrain > Engine > Active Test

Tester Display

Measurement Item

Control Range

Diagnostic Note

Control the Engine Cooling Fan Duty Ratio

Control the cooling fan

0 to 100%

Perform this test when vehicle is stopped.
Powertrain > Engine > Active Test

Tester Display

Control the Engine Cooling Fan Duty Ratio

OK:

Cooling fan operates smoothly.

NG

GO TO COOLING FAN SYSTEM

OK

2.

CHECK REFRIGERANT PRESSURE

(a) Install a manifold gauge set.

(b) Prepare the vehicle according to the table below.

Item

Condition

Vehicle doors

Fully open

Temperature setting

MAX COLD

Blower speed

HI

A/C switch

On

Recirculation/fresh switch

RECIRCULATION

Interior temperature

25 to 35°C (77 to 95°F)

(c) Read the manifold gauge pressure when the following conditions are met.

Standard Pressure:

Low pressure side

150 to 250 kPa (1.5 to 2.5 kgf/cm2, 22 to 36 psi)

High pressure side

1370 to 1570 kPa (14 to 16 kgf/cm2, 199 to 228 psi)

HINT:

The standard pressure is applicable when the refrigerant gas is filled to the correct amount.

Result:

Proceed to

OK

NG

*a

LO

*b

HI

Post-procedure1

(d) None

NG

CHARGE REFRIGERANT

OK

3.

CLEAR DTC

(a) Clear the DTCs.

Body Electrical > Air Conditioner > Clear DTCs
NEXT

4.

READ OUTPUT DTC (DTC B14744B)

Pre-procedure1

(a) Set the vehicle so that the conditions for detecting DTCs are met.

(1) Put the vehicle in Inspection Mode (engine forced to idle).

HINT:

Click here

(2) Prepare the vehicle according to the table below for 30 minutes.

Item

Condition

Blower speed

HI

A/C switch

On

Temperature setting

MAX COLD

Procedure1

(b) Check for DTCs.

Body Electrical > Air Conditioner > Trouble Codes

NOTICE:

If the engine idles continuously when ambient temperature is high, the compressor with motor assembly may automatically stop to protect the inverter circuit, and DTC B14744B may be stored.

Result

Proceed to

B14744B is not output

A

B14744B is output

B

Post-procedure1

(c) None

A

USE SIMULATION METHOD TO CHECK

B

REPLACE COMPRESSOR WITH MOTOR ASSEMBLY

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