Toyota CH-R Service Manual: Pressure Sensor Circuit (B1423)

DESCRIPTION

This DTC is stored if refrigerant pressure on the high pressure side is extremely low (195 kPa (2.0 kgf/cm2, 28 psi) or less) or extremely high (2812 kPa (28.7 kgf/cm2, 408 psi) or more). The air conditioner pressure (2 words) 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 conditioner pressure (2 words) converts this signal to a pressure value according to the sensor characteristics and uses it to control the compressor.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Memory
B1423	Pressure Sensor Circuit	Open in air conditioner pressure sensor circuit Short in air conditioner pressure sensor circuit Refrigerant pressure on high pressure side is extremely low (195 kPa (2.0 kgf/cm2, 28 psi) or less) or extremely high (2812 kPa (28.7 kgf/cm2, 408 psi) or more)	Air conditioner pressure sensor Harness or connector between air conditioner pressure sensor and air conditioning amplifier assembly 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)	-

		Vehicle Condition
		Pattern 1	Pattern 2	Pattern 3	Pattern 4
Diagnosis Condition	Ignition switch ON	○	○	○	○
Malfunction Status	Open in air conditioner pressure sensor circuit	○	-	-	-
	Short in air conditioner pressure sensor circuit	-	○	-	-
	Refrigerant pressure on high pressure side is extremely low (195 kPa (2.0 kgf/cm2, 28 psi) or less)	-	-	○	-
	Refrigerant pressure on high pressure side is extremely high (2812 kPa (28.7 kgf/cm2, 408 psi) or more)	-	-	-	○
Detection Time		4 seconds or more	4 seconds or more	4 seconds or more	4 seconds or more
Number of Trips		1 trip	1 trip	1 trip	1 trip

WIRING DIAGRAM

CAUTION / NOTICE / HINT

HINT:

If DTC B1423/23 and B14B8 are output at the same time, troubleshoot for DTC B14B8 first.

Click here

PROCEDURE

1.	CHECK FOR DTC

(a) Check for DTCs.

Click here

Body Electrical > Air Conditioner > Trouble Codes

Result	Proceed to
DTC B14B8 is output	A
DTC B14B8 is not output	B

A

GO TO DTC B14B8

B

2.	CHECK REFRIGERANT SHORTAGE

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

Measurement Condition:

Item	Condition
A/C switch	On
Ambient temperature*	0 to 49°C (32 to 120°F)
Blower speed	HI

*: If the ambient temperature is not within the range shown, do not perform this check.

(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 / Utility / Refrigerant Gas Volume Check.

Body Electrical > Air Conditioner > Utility

Tester Display
Refrigerant Gas Volume Check

Result	Amount of Refrigerant
Refrigerant shortage	Insufficient or leakage
Refrigerant correct	Correct

Result	Proceed to
Insufficient or leakage	A
Correct	B

B

GO TO STEP 4

A

3.	REPAIR AIR CONDITIONING SYSTEM LEAK

(a) Identify the area where refrigerant leaks from.

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(b) Repair the identified area of the air conditioning system.

(c) Evacuate the air conditioning system.

NEXT

CHARGE SYSTEM WITH REFRIGERANT

4.	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

CHARGE SYSTEM WITH REFRIGERANT

NG

5.	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 ON	4.75 to 5.25 V

NG

GO TO STEP 10

OK

6.	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 9

OK

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
A52-2 (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

8.	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 (evaporator temperature sensor) 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 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

9.	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

10.	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