B1479

HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM: B1479: Flow Sensor Circuit
B1479 - Flow Sensor Circuit

DESCRIPTION

The flow sensor is built into the compressor, and outputs a signal indicating the flow rate of the refrigerant. The air conditioning amplifier converts the received signal to refrigerant flow rate data according to the characteristics of the sensor, which it then sends to the ECM via CAN communication.





*1: As the flow sensor measures the flow rate of the refrigerant in the air conditioning system, it is necessary to turn the ignition switch to ON in order to check the state of the flow sensor.

WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
This DTC is stored when there is no refrigerant in the system, so check refrigerant volume and pressure first when this DTC is output Refrigerant.

PROCEDURE

1. READ VALUE USING TECHSTREAM (FLOW SENSOR)

(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) According to the display on the Techstream, read the Data List.

Air Conditioning





Result





B -- READ VALUE USING TECHSTREAM (FLOW SENSOR)
A -- Continue to next step.

2. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER ASSEMBLY - FLOW SENSOR)

(a) Disconnect the D16 air conditioning amplifier assembly connector.

(b) Disconnect the B33 cooler compressor assembly (flow sensor) connector.

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

Standard Resistance:





(d) Reconnect the cooler compressor assembly (flow sensor) connector.

(e) Reconnect the air conditioning amplifier assembly connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

3. REPLACE COOLER COMPRESSOR ASSEMBLY (FLOW SENSOR)

(a) Replace the cooler compressor assembly (flow sensor) with a normal one Removal

NEXT -- Continue to next step.

4. CHECK FOR DTC

(a) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

(b) Check for DTCs Reading and Clearing Diagnostic Trouble Codes.

OK:

DTC B1479 is not output.

NG -- REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Removal

OK -- END (COOLER COMPRESSOR ASSEMBLY (FLOW SENSOR) IS FAULTY)

5. READ VALUE USING TECHSTREAM (FLOW SENSOR)

(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) According to the display on the Techstream, read the Data List.

Air Conditioning





Result





B -- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Symptom Related Diagnostic Procedures

C -- CHECK FOR DTC
A -- Continue to next step.

6. CHECK REFRIGERANT PRESSURE

(a) Install the manifold gauge set.

(b) Read the gauge pressure to check that refrigerant has been charged Refrigerant.

OK:

Refrigerant is charged.

NG -- CHARGE REFRIGERANT Service and Repair
OK -- Continue to next step.

7. REPLACE COOLER COMPRESSOR ASSEMBLY (FLOW SENSOR)

(a) Replace the cooler compressor assembly (flow sensor) with a normal one Removal.

NOTICE:
In some cases, this DTC is stored when the magnetic clutch is not functioning properly, so inspect the magnet clutch clearance before replacing the cooler compressor assembly (flow sensor) Reassembly.

OK -- Continue to next step.

8. CHECK FOR DTC

(a) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

(b) Check for DTCs Reading and Clearing Diagnostic Trouble Codes.

OK:

DTC B1479 is not output.

NG -- REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Removal

OK -- END (COOLER COMPRESSOR ASSEMBLY (FLOW SENSOR) IS FAULTY)