DTC B1474-4B: A/C Inverter Cooling/Heating Over Temperature [08/2023 - ]: Procedure

1. Perform the Active Test according to the display on the GTS.

   Powertrain > Engine > Active Test 

   Tester Display	Measurement Item	Control Range	Restrict Condition
   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

   Electric cooling fan operates smoothly.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

GO TO COOLING FAN SYSTEM. Refer to  ON-VEHICLE INSPECTION [10/2022 - ] 

Result: 

OK 

See step  2

Pre-procedure1

• Install a manifold gauge set.

  HINT: 

  Refer to ON-VEHICLE INSPECTION [10/2022 - ]

• Prepare the vehicle according to the table below.

  Measurement Condition

  Item	Condition
  Doors	Fully open
  A/C Switch	On
  Recirculation/fresh Control Switch	Recirculation
  Set Temperature	MAX COLD
  Blower Speed	HI
  Air Conditioning Air Inlet Temperature	25 to 35°C (77 to 95°F)

• Read the manifold gauge pressure.

  Standard Pressure

  Item	Specified Condition	Result
  High pressure side	1630 to 1830 kPa 16.6 to 18.7 kgf/cm2 236 to 265 psi	kPa kgf/cm2 psi
  Low pressure side	150 to 250 kPa 1.5 to 2.5 kgf/cm2 22 to 36 psi	kPa kgf/cm2 psi

  Result

  Proceed to
  OK
  NG

Post-procedure1

• None

Result: 

NG 

CHARGE REFRIGERANT. Refer to  REPLACEMENT [08/2023 - ] 

Result: 

OK 

See step  3

1. Clear the DTCs.

   Body Electrical > Air Conditioner > Clear DTCs 

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  4

Pre-procedure1

• Set the vehicle condition when the DTCs are output.
  1. Set the "Inspection Mode".

     HINT: 

     Refer to INSPECTION MODE PROCEDURE [10/2022 - ]

  2. Prepare the vehicle according to the table below for 30 minutes or more.

     Item	Condition
     Blower Speed	HI
     A/C Switch	On
     Set Temperature	MAX COLD

• Check for DTCs.

  Body Electrical > Air Conditioner > Trouble Codes 

  NOTE:

  If the engine keeps idling when the ambient temperature is high, the compressor with motor assembly may automatically stop to protect the inverter circuit, and DTC B1474-4B may be stored.

  Result

  Result	Proceed to
  B1474-4B is not output	A
  B1474-4B is output	B

Post-procedure1

• None

Result: 

A 

USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2022 - ] 

Result: 

B 

REPLACE COMPRESSOR WITH MOTOR ASSEMBLY. Refer to  REMOVAL [08/2023 - ]