INSPECTION PROCEDURE 3: Cannot communicate with the A/C compressor.


caution If there is any problem in the CAN bus lines, an incorrect diagnosis code may be stored. Prior to this diagnosis, always diagnose the CAN bus lines.


COMMENTS ON TROUBLE SYMPTOM


The PHEV-ECU, the power supply or the earth connection to the A/C compressor or the A/C compressor itself may be defective when the PHEV-ECU cannot communicate with the A/C compressor inverter for at least eight seconds.

PROBABLE CAUSES




DIAGNOSIS PROCEDURE


STEP 1. Voltage measurement at A/C compressor assembly connector.


(1)Disconnect the connector, and measure at the wiring harness side.
(2)Voltage between 12V terminal and body earth.
OK: System voltage

Q. Is the check result normal?

Go to Step 3.
Go to Step 2.

STEP 2. Check of open circuit in power supply line between IGCT control relay and A/C compressor assembly connector.


Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).
Repair the wiring harness.

STEP 3. Resistance measurement at the A/C compressor assembly connector.


(1)Disconnect the connector, and measure at the wiring harness side.
(2)Continuity between A/C compressor earth terminal and body earth
OK: Continuity exists (2 Ω or less)

Q. Is the check result normal?

Go to Step 4.
Go to Step 6.

STEP 4. Check of open circuit in COMH, COML line between PHEV-ECU connector and A/C compressor assembly connector.


Q. Is the check result normal?

Go to Step 5.
Repair the connector(s) or wiring harness.

STEP 5. After replacing the PHEV-ECU, check again if the diagnosis code is stored.


Q. Is the diagnosis code stored?

Replace the A/C compressor.
Intermittent malfunction. Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points, - How to Cope with Intermittent Malfunctions .)

STEP 6. Check of open circuit in GND line between A/C compressor assembly connector and earth connector.


Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).
Repair the connector(s) or wiring harness.