| Last Modified: 07-31-2024 | 6.11:8.1.0 | Doc ID: RM1000000026Z41 |
| Model Year Start: 2023 | Model: Corolla | Prod Date Range: [09/2022 - ] |
| Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for HV Model): B14744B; A/C Inverter Cooling/Heating Over Temperature; 2023 - 2025 MY Corolla Corolla HV [09/2022 - ] | ||
|
DTC |
B14744B |
A/C Inverter Cooling/Heating Over Temperature |
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:
Malfunction:
Detection Time:
|
|
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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![2019 - 2025 MY Corolla Corolla Hatchback Corolla HV GR Corolla [06/2018 - ]; INTRODUCTION: REPAIR INSTRUCTION: PRECAUTION](/t3Portal/stylegraphics/info.gif)
-
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.
-
Before disconnecting battery:
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-
Automatic learning chart:
Click here
-
Before disconnecting battery:
-
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 |
Restrict Condition |
|---|---|---|---|
|
Control the Engine Cooling Fan |
Control electric cooling fan motor |
OFF/Low/High |
Perform this test when vehicle is stopped. |
Powertrain > Engine > Active Test
|
Tester Display |
|---|
|
Control the Engine Cooling Fan |
OK:
Electric cooling fan operates smoothly.
| NG |
|
|
|
2. |
CHECK REFRIGERANT PRESSURE |
(a) Install a manifold gauge set.
for HFC-134a(R134a): Click here
for HFO-1234yf(R1234yf): Click here
(b) 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) |
(c) Read the manifold gauge pressure.
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)
| NG |
|
CHARGE REFRIGERANT for HFC-134a(R134a): Click here
for HFO-1234yf(R1234yf): Click here
|
|
|
3. |
CLEAR DTC |
(a) Clear the DTCs.
Body Electrical > Air Conditioner > Clear DTCs
|
|
4. |
CHECK FOR DTC |
(a) Set the vehicle condition when the DTCs are output.
(1) Set the "Inspection Mode".
Click here
(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 |
(b) Check for DTCs.
Body Electrical > Air Conditioner > Trouble Codes
NOTICE:
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 B14744B may be stored.
|
Result |
Proceed to |
|---|---|
|
DTC B14744B is not output |
A |
|
DTC B14744B is output |
B |
| A |
|
| B |
|
REPLACE COMPRESSOR WITH MOTOR ASSEMBLY
|
|
|