Toyota CH-R Service Manual: Refrigerant Shortage (B14B8)

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	When following condition is detected in refrigerant shortage check in normal operation: Amount of refrigerant is insufficient	Refrigerant pipe line Cooler expansion valve Air conditioning amplifier assembly	Memorized (15 min. or more)*

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 Max.: 3294.3 kPaG	Actual refrigerant pressure displayed	-

Body Electrical > Air Conditioner > Data List

Tester Display
Regulator Pressure Sensor

(f) Install a manifold gauge set.

Click here

(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 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)

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.

OK

CHECK REFRIGERANT PRESSURE

NG

2.	CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)

(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
A52-3 (+) - A52-1 (-)	Ignition switch to 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) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
A52-1 (-) - 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 F138 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
A52-2 (PR) - F138-24 (PRE)	Always	Below 1 Ω
A52-2 (PR) or F138-24 (PRE) - Body ground	Always	10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

5.	INSPECT AIR CONDITIONER PRESSURE SENSOR (SENSOR SIGNAL CIRCUIT)

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

Measurement Condition:

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)

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 Condition Specified Condition F138-24 (PRE) - Body ground Ignition switch to ON (A/C switch: On) 0.74 to 4.61 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 Max.: 3294.3 kPaG	Actual refrigerant pressure displayed	-

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 F138 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
A52-1 (-) - F138-2 (SG-2)	Always	Below 1 Ω
A52-1 (-) or F138-2 (SG-2) - 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 F138 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
A52-3 (+) - F138-6 (S5-3)	Always	Below 1 Ω
A52-3 (+) or F138-6 (S5-3) - Body ground	Always	10 kΩ or higher

OK

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR