B1498

AIR CONDITIONING: AIR CONDITIONING SYSTEM: B1498/98: Communication Malfunction (A/C Inverter Local)
B1498/98 - Communication Malfunction (A/C Inverter Local)

DESCRIPTION

The hybrid vehicle control ECU and compressor transmit information to one another via the CAN and multiplex communication lines. Compressor control is stopped and the DTC is output if communication information is cut off or abnormal information occurs.

The DTC is also detected if high-voltage power supplied from the inverter assembly to the compressor control circuit is shut off.

The output DTC is memorized as previous trouble.

CAUTION:
* Wear electrically insulated gloves and pull out the service plug grip before inspection as procedures may require disconnecting high-voltage connectors. Be sure to carry the removed service plug grip because other workers may install it by mistake.
* Do not touch the high-voltage connectors or terminals for 10 minutes after the service plug grip is removed.
NOTICE:
* This circuit uses both CAN and multiplex communication. Before performing the inspection, check that the CAN and multiplex communication systems are functioning normally.
* If abnormal information occurs as a result of the timing of the power switch and the high-voltage power supply, this DTC may be output. If the DTC is a past trouble, check the fuse and the wire harness. If there is no malfunction, erase the DTC.





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK FOR DTC

(a) Check if DTCs for the hybrid control system are output using the Techstream.

Result





B -- GO TO HYBRID CONTROL SYSTEM How To Proceed With Troubleshooting
A -- Continue to next step.

2. INSPECT FUSE (A/C W/P)

(a) Remove the A/C W/P fuse from the main body ECU LH.

(b) Measure the resistance of the fuse.

Standard resistance:

Below 1 Ohms

NG -- REPLACE FUSE
OK -- Continue to next step.

3. CHECK WIRE HARNESS (COMPRESSOR - BODY GROUND)

(a) Disconnect the E85 compressor connector.





CAUTION:
Do not disconnect the connector on the high-voltage side.

(b) Measure the resistance of the wire harness side connector.

Standard resistance:





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

4. CHECK WIRE HARNESS (COMPRESSOR - BATTERY AND BODY GROUND)

(a) Disconnect the E85 compressor connector.





(b) Measure the voltage of the wire harness side connector.

Standard voltage:





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

5. CHECK WIRE HARNESS (HYBRID VEHICLE CONTROL ECU - COMPRESSOR)

(a) Disconnect the E84 hybrid vehicle control ECU connector.





(b) Disconnect the E85 compressor connector.

(c) Measure the resistance of the wire harness side connectors.

Standard resistance:





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

6. INSPECT ELECTRIC VEHICLE FUSE (COMP)

(a) Turn the power switch OFF.

(b) Remove the service plug grip.

CAUTION:
* Be sure to wear insulated gloves.
* Do not touch the high-voltage connectors or terminals for 10 minutes after the service plug grip is removed.
NOTICE:
Do not start the engine with the service plug grip removed because it may cause a malfunction.

(c) Remove the inverter cover.

NOTICE:
* Tape the interlock round terminal of the inverter cover to prevent it from being grounded.
* Be sure to prevent foreign objects or water from entering the inverter assembly.

(d) Check that the A and B bolts are tightened securely.





(e) Measure the resistance of the fuse.

Standard resistance:

Below 1 Ohms

NG -- REPLACE FUSE
OK -- Continue to next step.

7. INSPECT AIR CONDITIONING HARNESS





(a) Disconnect the w8 and w9 air conditioning harness connectors.

CAUTION:
Be sure to wear insulated gloves.

(b) Measure the resistance of the air conditioning harness.

Standard resistance:





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

8. CHECK COMPRESSOR ASSEMBLY

(a) Reconnect the w8 and w9 air conditioning harness connectors.





(b) Disconnect the E84 hybrid vehicle control ECU connector.

(c) Reconnect the E85 compressor connector.

(d) Using an oscilloscope, check the waveform 1.





Waveform 1 (Reference):





OK:

Waveform appears.

HINT
Waveform cycle varies with the communication contents.

(e) Using an oscilloscope, check the waveform 2.





Waveform 1 (Reference):





OK:

Waveform appears.

HINT
Waveform cycle varies with the communication contents.

OK -- REPLACE HYBRID VEHICLE CONTROL ECU
NG -- Continue to next step.

9. REPLACE COMPRESSOR ASSEMBLY

NEXT -- Continue to next step.

10. CHECK FOR DTC

(a) Clear the DTC DTC Check / Clear.

(b) Check for the DTC again DTC Check / Clear.

Result





B -- END

A -- REPLACE HYBRID VEHICLE CONTROL ECU