Last Modified: 01-30-2024 6.11:8.1.0 Doc ID: RM100000001QM7N
Model Year Start: 2021 Model: RAV4 Prod Date Range: [08/2020 -           ]
Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for Gasoline Model): B14B8; Refrigerant Shortage; 2021 - 2024 MY RAV4 [08/2020 -        ]

DTC

B14B8

Refrigerant Shortage

DESCRIPTION

This DTC is stored if the amount of refrigerant in the air conditioning system is insufficient.

The air conditioning amplifier assembly receives the ambient temperature signal, refrigerant pressure signal, etc. from various sensors.

Based on these signals, the air conditioning amplifier assembly detects the amount of refrigerant.

The A/C switch indicator is turned off and the air conditioning system is stopped if the amount of refrigerant is insufficient.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Memory

B14B8

Refrigerant Shortage
  • Diagnosis condition: The amount of refrigerant is judged to be insufficient in normal operation
  • Malfunction status: When following condition is detected in refrigerant shortage check in normal operation; Amount of refrigerant is insufficient
  • Detection time: During air conditioning system operation for 10 minutes or more
  • Refrigerant pipe line (leaks, stuck)
  • Cooler expansion valve
  • Air conditioning amplifier assembly
  • Lack of refrigerant gas

Memorized

WIRING DIAGRAM

PROCEDURE

1.

CHECK REFRIGERANT PRESSURE

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(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.: -456.6 kPaG (gauge)

Max.: 3294.3 kPaG (gauge)

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

Body Electrical > Air Conditioner > Data List

Tester Display

Regulator Pressure Sensor

(f) Install a manifold gauge set.

Click here 2019 - 2024 MY RAV4 RAV4 HV [02/2019 -        ]; HEATING / AIR CONDITIONING: REFRIGERANT (for HFO-1234yf(R1234yf)): ON-VEHICLE INSPECTION

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

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

Measurement Condition:

Item

Condition

Vehicle Condition

Engine running

Doors

Fully closed (windows also fully closed)

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)

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)

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

OK:

The values displayed in the Data List and on the manifold gauge match.

NG

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

OK

2.

CHECK HARNESS AND CONNECTOR (AIR CONDITIONER PRESSURE SENSOR - POWER SOURCE)

(a) Disconnect the air conditioner pressure sensor connector.

*a

Front view of wire harness connector

(to Air Conditioner Pressure Sensor)

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

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

A22-3 (+) - Body ground

Ignition switch ON

4.75 to 5.25 V
NG

GO TO STEP 7

OK

3.

CHECK HARNESS AND CONNECTOR (AIR CONDITIONER PRESSURE SENSOR - BODY GROUND)

(a) Disconnect the air conditioner pressure sensor connector.

*a

Front view of wire harness connector

(to Air Conditioner Pressure Sensor)

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A22-1 (-) - Body ground

Always

Below 1 Ω
NG

GO TO STEP 6

OK

4.

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

(a) Disconnect the G47 air conditioning amplifier assembly connector.

(b) Disconnect the A22 air conditioner pressure sensor connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

G47-6 (PRE) - A22-2 (PR)

Always

Below 1 Ω

G47-6 (PRE) or A22-2 (PR) - Other terminals and body ground

Always

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

5.

INSPECT AIR CONDITIONING AMPLIFIER ASSEMBLY (SENSOR SIGNAL CIRCUIT)

(a) Measure the voltage when the following conditions are met.

Measurement Condition:

Item

Condition

Vehicle Condition

Engine running

Doors

Fully closed (windows also fully closed)

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)

NOTICE:

  • If refrigerant pressure on the high pressure side becomes extremely high during the inspection (if the voltage exceeds 4.61 V), the fail-safe function stops compressor operation. Therefore, measure the voltage before the fail-safe operation.
  • It is necessary to measure the voltage for a certain amount of time (approximately 10 minutes) because the malfunction may recur after a while.

HINT:

When the outside air temperature is low (below -1.5°C (29.3°F)), the compressor stops due to operation of the thermistor assembly and the No. 1 cooler thermistor to prevent the evaporator from freezing. In this case, perform the inspection in a warm indoor environment.

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

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

G47-6 (PRE) - Body ground
  • Engine running
  • Air conditioning system operating

0.74 to 4.61 V (While sensor voltage is 5 V)

*a

Component with harness connected

(Air Conditioning Amplifier Assembly)

(b) Connect the Techstream to the DLC3.

(c) Turn the ignition switch to ON.

(d) Turn the Techstream on.

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

(f) 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.: -456.6 kPaG (gauge)

Max.: 3294.3 kPaG (gauge)

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

Body Electrical > Air Conditioner > Data List

Tester Display

Regulator Pressure Sensor

OK:

The voltage and value displayed in the Data List change.

Result

Proceed to

OK

A

NG (The voltage changes but the value displayed in the Data List does not change.)

NG (The voltage does not change.)

B
A

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

B

REPLACE AIR CONDITIONER PRESSURE SENSOR

6.

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

(a) Disconnect the G47 air conditioning amplifier assembly connector.

(b) Disconnect the A22 air conditioner pressure sensor connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

G47-15 (SG-4) - A22-1 (-)

Always

Below 1 Ω

G47-15 (SG-4) or A22-1 (-) - Other terminals and body ground

Always

10 kΩ or higher
OK

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

7.

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

(a) Disconnect the G47 air conditioning amplifier assembly connector.

(b) Disconnect the A22 air conditioner pressure sensor connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

G47-11 (S5-3) - A22-3 (+)

Always

Below 1 Ω

G47-11 (S5-3) - A22-3 (+) - Other terminals and body ground

Always

10 kΩ or higher
OK

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR