B1423
AIR CONDITIONING: AIR CONDITIONING SYSTEM: B1423/23: Pressure Sensor Circuit
DTC B1423/23 - Pressure Sensor Circuit
DESCRIPTION
This DTC is output when refrigerant pressure is extremely low (0.19 MPa (2.0 kgf/cm2, 28 psi) or less) or extremely high (3.14 MPa (32.0 kgf/cm2, 455 psi) or more). The pressure sensor, which is installed on the pipe of the high pressure side to detect refrigerant pressure, outputs a refrigerant pressure signal to the A/C amplifier. The A/C amplifier converts this signal to pressure according to the sensor characteristics to control the compressor.
HINT:
Be sure to check the refrigerant volume first when this DTC is output because this DTC can also be output if there is no refrigerant in the system.
WIRING DIAGRAM
INSPECTION PROCEDURE
PROCEDURE
1. CHECK REFRIGERANT
(a) Check the sight glass of the cooler unit refrigerant liquid pipe.
(1) Prepare the vehicle according to the chart below.
(2) Compare the sight glass to the following chart.
*: Bubbles in the sight glass with the vehicle interior temperature above 35°C (95°F) can be considered normal if cooling is sufficient.
NG -- CHARGE REFRIGERANT
OK -- Continue to next step.
2. CHECK WIRE HARNESS (PRESSURE SENSOR - A/C AMPLIFIER)
(a) Disconnect the pressure sensor connector.
(b) Disconnect the A/C amplifier connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
3. INSPECT PRESSURE SENSOR
(a) Install the manifold gauge set Refrigerant.
(b) Connect the three 1.5 V dry cell batteries' positive (+) lead to terminal 3 and the negative (-) lead to terminal 1. Then connect the voltmeter's positive (+) lead to terminal 2 and the negative (-) lead to terminal 1. Measure the voltage.
OK:
The voltage changes according to refrigerant pressure, as shown in the graph.
Result:
C -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
B -- REPLACE AIR CONDITIONING AMPLIFIER
A -- REPLACE PRESSURE SENSOR