Last Modified: 05-13-2024 6.11:8.1.0 Doc ID: RM100000001H978
Model Year Start: 2020 Model: Corolla Prod Date Range: [01/2019 - 09/2022]
Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for HV Model): B1423; Open in Pressure Sensor Circuit / Abnormal Refrigerant Pressure; 2020 - 2022 MY Corolla Corolla HV [01/2019 - 09/2022]

DTC

B1423

Open in Pressure Sensor Circuit / Abnormal Refrigerant Pressure

DESCRIPTION

This DTC is stored if refrigerant pressure on the high pressure side is extremely low (176 kPaG (1.8 kgf/cm2, 26 psi) or less*1, 196 kPaG (2.0 kgf/cm2, 28 psi) or less*2) or extremely high (3025 kPaG (30.8 kgf/cm2, 439 psi) or more*1, 2812 kPaG (28.7 kgf/cm2, 408 psi) or more*2). The air conditioner pressure sensor, which is installed to the high pressure side pipe to detect refrigerant pressure, sends a refrigerant pressure signal to the air conditioning amplifier assembly. The air conditioning amplifier assembly converts this signal to a pressure value according to the sensor characteristics and uses it to control the compressor.

  • *1: for HFC-134a (R134a)
  • *2: for HFO-1234yf (R1234yf)

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Memory

B1423

Open in Pressure Sensor Circuit / Abnormal Refrigerant Pressure
  • Open or short in air conditioner pressure sensor circuit

for HFC-134a (R134a):

  • Refrigerant pressure on high pressure side is extremely low (176 kPaG (1.8 kgf/cm2, 26 psi) or less) or extremely high (3025 kPaG (30.8 kgf/cm2, 439 psi) or more)

for HFO-1234yf (R1234yf):

  • Refrigerant pressure on high pressure side is extremely low (196 kPaG (2.0 kgf/cm2, 28 psi) or less) or extremely high (2812 kPaG (28.7 kgf/cm2, 408 psi) or more)
  • Air conditioner pressure sensor
  • Harness or connector
  • Air conditioning amplifier assembly
  • Cooler expansion valve (blocked, stuck)
  • Cooler condenser assembly (blocked, deterioration of cooling capacity due to dirt)
  • Cooler dryer (moisture in the refrigerant cycle cannot be absorbed)
  • Cooling fan system (cooler condenser assembly cannot be cooled down)
  • Air conditioning system (leaks, blocked)
  • Refrigerant volume (excessive, low)

-

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • Be sure to check the refrigerant volume first when this DTC is output because this DTCcan also be stored if there is no refrigerant in the cycle.

    for HFC-134a (R134a): Click here 2020 - 2025 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 -        ]; HEATING / AIR CONDITIONING: REFRIGERANT (for HFC-134a(R134a)): REPLACEMENT

    for HFO-1234yf (R1234yf): Click here 2020 - 2021 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 - 06/2020]; HEATING / AIR CONDITIONING: REFRIGERANT (for HFO-1234yf(R1234yf)): REPLACEMENT 2021 - 2025 MY Corolla Corolla Hatchback Corolla HV GR Corolla [06/2020 -        ]; HEATING / AIR CONDITIONING: REFRIGERANT (for HFO-1234yf(R1234yf)): REPLACEMENT

  • If DTC B1423 and B14B8 are output at the same time, troubleshoot for DTC B14B8 first.

    Click here 2020 - 2022 MY Corolla Corolla HV [01/2019 - 09/2022]; HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for HV Model): B14B8; Refrigerant Shortage

HINT:

Make sure that the connector is properly connected. If it is not, securely connect it and check for DTCsagain.

PROCEDURE

1.

CHECK FOR DTC

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Air Conditioner / Data List.

(e) Check for DTCs.

Body Electrical > Air Conditioner > Trouble Codes

Result

Proceed to

B14B8 is not output

A

B14B8 is output

B
B

GO TO DTC B14B8

A

2.

COMPARE REFRIGERANT GAS PRESSURE VALUES SHOWN ON TECHSTREAM AND MANIFOLD GAUGE SET

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Air Conditioner / Data List.

(e) Read the Data List according to the display on the Techstream.

Body Electrical > Air Conditioner > Data List

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

Regulator Pressure Sensor

Air conditioner pressure sensor

Min.: -456.68 kPaG

Max.: 3294.37 kPaG

Actual refrigerant pressure displayed
  • Refrigerant line (gas leak etc.)
  • Air conditioner pressure sensor circuit malfunction

Body Electrical > Air Conditioner > Data List

Tester Display

Regulator Pressure Sensor

(f) Install a manifold gauge set.

for HFC-134a (R134a): Click here 2020 - 2025 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 -        ]; HEATING / AIR CONDITIONING: REFRIGERANT (for HFC-134a(R134a)): ON-VEHICLE INSPECTION

for HFO-1234yf (R1234yf): Click here 2020 - 2025 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 -        ]; HEATING / AIR CONDITIONING: REFRIGERANT (for HFO-1234yf(R1234yf)): ON-VEHICLE INSPECTION

(g) Compare the values displayed in the Data List and on the manifold gauge set.

Result

Proceed to

Data List value and manifold gauge set value do not match and Data List value: 176 kPaG (1.8 kgf/cm2, 26 psi) or less*1, 196 kPaG (2.0 kgf/cm2, 28 psi) or less*2

A

Data List value and manifold gauge set value do not match and Data List value: 3025 kPaG (30.8 kgf/cm2, 439 psi) or more*1, 2812 kPaG (28.7 kgf/cm2, 408 psi) or more*2

B

Data List value matches manifold gauge set value

C
  • *1: for HFC-134a (R134a)
  • *2: for HFO-1234yf (R1234yf)
B

GO TO STEP 8

C

GO TO ON-VEHICLE INSPECTION (CHECK REFRIGERANT PRESSURE USING GAUGE)

for HFC-134a (R134a): Click here 2020 - 2025 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 -        ]; HEATING / AIR CONDITIONING: REFRIGERANT (for HFC-134a(R134a)): ON-VEHICLE INSPECTION

for HFO-1234yf (R1234yf): Click here 2020 - 2025 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 -        ]; HEATING / AIR CONDITIONING: REFRIGERANT (for HFC-134a(R134a)): ON-VEHICLE INSPECTION

A

3.

READ VALUE USING TECHSTREAM (REGULATOR PRESSURE SENSOR)

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Air Conditioner / Data List.

(e) Read the Data List according to the display on the Techstream.

Body Electrical > Air Conditioner > Data List

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

Regulator Pressure Sensor

Air conditioner pressure sensor

Min.: -456.68 kPaG

Max.: 3294.37 kPaG

Actual refrigerant pressure displayed
  • Refrigerant line (gas leak etc.)
  • Air conditioner pressure sensor circuit malfunction

Body Electrical > Air Conditioner > Data List

Tester Display

Regulator Pressure Sensor

OK:

Disconnecting the A61 connector of the air conditioner pressure sensor causes the Data List value to change.

Result

Proceed to

Regulator pressure sensor value changes

A

Regulator pressure sensor value does not change

B
B

GO TO STEP 6

A

4.

CHECK TERMINAL VOLTAGE (AIR CONDITIONER PRESSURE SENSOR)

(a) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection

Condition

Specified Condition

A61-3 (+) - Body ground

Power switch on (IG)

4.75 to 5.25 V

*a

Front view of wire harness connector

(to Air Conditioner Pressure Sensor)
OK

REPLACE AIR CONDITIONER PRESSURE SENSOR

NG

5.

CHECK HARNESS AND CONNECTOR (AIR CONDITIONER PRESSURE SENSOR - AIR CONDITIONING AMPLIFIER ASSEMBLY)

(a) Disconnect the I48 air conditioning amplifier assembly connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

A61-3 (+) - I48-11 (S5-3)

Always

Below 1 Ω
OK

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

6.

CHECK TERMINAL VOLTAGE (AIR CONDITIONING AMPLIFIER ASSEMBLY)

(a) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection

Condition

Specified Condition

A61-2 (PR) - Body ground

Power switch on (IG)

3.0 to 5.25 V

*a

Front view of wire harness connector

(to Air Conditioner Pressure Sensor)
OK

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

NG

7.

CHECK HARNESS AND CONNECTOR (AIR CONDITIONER PRESSURE SENSOR - AIR CONDITIONING AMPLIFIER ASSEMBLY)

(a) Disconnect the I48 air conditioning amplifier assembly connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

A61-2 (PR) or I48-6 (PRE) - Other terminals and body ground

Always

10 kΩ or higher
OK

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

8.

CHECK HARNESS AND CONNECTOR

(a) Disconnect the A61 air conditioner pressure sensor connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

A61-1 (-) - Body ground

Always

Below 1 Ω
NG

GO TO STEP 14

OK

9.

CHECK TERMINAL VOLTAGE

(a) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection

Condition

Specified Condition

A61-2 (PR) - Body ground

Power switch on (IG)

3.0 to 5.25 V

*a

Front view of wire harness connector

(to Air Conditioner Pressure Sensor)

Result

Proceed to

5.25 V or higher

A

3.0 to 5.25 V

B

Below 3.0 V

C
B

GO TO STEP 11

C

GO TO STEP 13

A

10.

CHECK HARNESS AND CONNECTOR (AIR CONDITIONER PRESSURE SENSOR - AIR CONDITIONING AMPLIFIER ASSEMBLY)

(a) Disconnect the I48 air conditioning amplifier assembly connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

A61-2 (PR) or I48-6 (PRE) - Other terminals

Always

10 kΩ or higher
OK

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

11.

CHECK INTERNAL CIRCUIT RESISTANCE (AIR CONDITIONING AMPLIFIER ASSEMBLY)

(a) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

A61-3 (+) - A61-2 (PR)

Power switch off

180 to 220 kΩ

HINT:

After turning the power switch off, wait at least 30 seconds before performing the measurement.

OK

REPLACE AIR CONDITIONER PRESSURE SENSOR

NG

12.

CHECK HARNESS AND CONNECTOR (AIR CONDITIONER PRESSURE SENSOR - AIR CONDITIONING AMPLIFIER ASSEMBLY)

(a) Disconnect the I48 air conditioning amplifier assembly connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

A61-2 (PR) or I48-6 (PRE) - A61-3 (+) or I48-11 (S5-3)

Always

10 kΩ or higher
OK

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

13.

CHECK HARNESS AND CONNECTOR (AIR CONDITIONER PRESSURE SENSOR - AIR CONDITIONING AMPLIFIER ASSEMBLY)

(a) Disconnect the I48 air conditioning amplifier assembly connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

A61-2 (PR) - I48-6 (PRE)

Always

Below 1 Ω
OK

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

14.

CHECK HARNESS AND CONNECTOR (AIR CONDITIONER PRESSURE SENSOR - AIR CONDITIONING AMPLIFIER ASSEMBLY)

(a) Disconnect the I48 air conditioning amplifier assembly connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

A61-1 (-) - I48-15 (SG-4)

Always

Below 1 Ω
OK

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR