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 with motor assembly transmit information to one another via the communication line. 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 with converter assembly to the compressor control circuit is shut off.

The output DTC is memorized as a past DTC.

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:
Depending on the timing of the power supply to the 12 V power supply circuit and high-voltage circuit when the power switch is turned ON (READY), an abnormal information signal may be output, causing this DTC to be stored. If the output DTC is a code that was memorized in the past, check the fuses and wire harnesses. If there is no malfunction, erase the DTC.





WIRING DIAGRAM





INSPECTION PROCEDURE

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:
Depending on the timing of the power supply to the 12 V power supply circuit and high-voltage circuit when the power switch is turned ON (READY), an abnormal information signal may be output, causing this DTC to be stored. If the output DTC is a code that was memorized in the past, check the fuses and wire harnesses. If there is no malfunction, erase the DTC.

PROCEDURE

1. CHECK DTC (CAN COMMUNICATION SYSTEM)

(a) Use the Techstream to check if the CAN communication system is functioning normally.

Result





B -- GO TO CAN COMMUNICATION SYSTEM How to Proceed With Troubleshooting
A -- Continue to next step.

2. CHECK DTC (HYBRID CONTROL SYSTEM)

(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.

3. INSPECT FUSE (E/G RM-IG1-1)

(a) Remove the E/G RM-IG1-1 fuse from the engine room No. 2 relay block.

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

Standard resistance:





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

4. CHECK HARNESS AND CONNECTOR (COMPRESSOR WITH MOTOR ASSEMBLY - BODY GROUND)

(a) Disconnect the E56 compressor with motor assembly connector.





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

(b) 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.

5. CHECK HARNESS AND CONNECTOR (COMPRESSOR WITH MOTOR ASSEMBLY - BATTERY)

(a) Disconnect the E56 compressor with motor assembly connector.





(b) Measure the voltage according to the value(s) in the table below.

Standard voltage:





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

6. CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - COMPRESSOR WITH MOTOR ASSEMBLY)

(a) Disconnect the E55 hybrid vehicle control ECU connector.





(b) Disconnect the E56 compressor with motor assembly 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.

7. INSPECT HIGH VOLTAGE FUSE

(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 connector cover assembly.

CAUTION:
Be sure to wear insulated gloves.

NOTICE:
Be sure to prevent foreign objects or water from entering the inverter with converter assembly.

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





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

Standard resistance:





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

8. INSPECT HEATER WIRE

(a) Disconnect the heater wire connectors.





CAUTION:
Be sure to wear insulated gloves.

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

Standard resistance:





NG -- REPLACE HEATER WIRE Removal
OK -- Continue to next step.

9. INSPECT COMPRESSOR WITH MOTOR ASSEMBLY

(a) Disconnect the E55 hybrid vehicle control ECU connector.





(b) Reconnect the E56 compressor with motor assembly connector.

(c) Using an oscilloscope, check the waveform.





Measurement condition





OK:

Waveform is as shown in the illustration.

HINT
Waveform cycle varies with the communication contents.





Measurement condition





OK:

Waveform is as shown in the illustration.

HINT
Waveform cycle varies with the communication contents.

NG -- REPLACE COMPRESSOR WITH MOTOR ASSEMBLY Removal

OK -- REPLACE HYBRID VEHICLE CONTROL ECU Removal