Diagnosis Item 40: Diagnose when the M.U.T.-III cannot receive the data sent by rear electric motor control unit.



caution When servicing a CAN bus line, earth yourself by touching a metal object such as an unpainted water pipe. If you fail to do, a component connected to the CAN bus line may be broken.

FUNCTION


The diagnostic result demonstrates that "the M.U.T.-III cannot receive the sent data from the rear electric motor control unit (RMCU)" when the M.U.T.-III checks the periodically sent data from each ECU and cannot receive the RMCU data only.

TROUBLE JUDGEMENT CONDITIONS


M.U.T.-III judges the trouble when the periodically sent data from RMCU cannot be received.

PROBABLE CAUSES




DIAGNOSIS PROCEDURE


STEP 1. Connector check: joint connector (CAN6) and RMCU connector


caution The strand end of the twist wire should be within 10 cm from the connector. For details refer to .
When checking the joint connector, ensure that its wiring harness side and its short pins are not damaged.

Q. Is the check result normal?

Go to Step 2.
Repair the defective connector. Replace the joint connector as necessary.

STEP 2. Resistance measurement at joint connector (CAN6) and RMCU connector.


caution A digital multimeter should be used. For details refer to .
caution The test wiring harness should be used. For details refer to .
(1)Disconnect joint connector (CAN6) and the RMCU connector, and measure at the wiring harness side.
(2)Turn off the power supply mode of the electric motor switch.
(3)
caution When measuring the resistance, disconnect the negative battery terminal. For details refer to .
Ensure that the negative battery terminal is disconnected.
(4)Continuity between joint connector (CAN6) terminal No.5 and RMCU connector terminal No.5
OK: Continuity (2 Ω or less)
(5)Continuity between joint connector (CAN6) terminal No.7 and RMCU connector terminal No.6
OK: Continuity (2 Ω or less)
caution Strictly observe the specified wiring harness repair procedure. For details refer to .

Q. Is the check result normal?

Go to Step 3
NO : Repair the wiring harness between joint connector (CAN6) and the RMCU connector.

STEP 3. Resistance measurement at RMCU connector.


danger Carry out the check on the high-voltage circuit while reading carefully the precautions on handling a high-voltage vehicle. Refer to GROUP 54D - Precautions on how to use the high-voltage vehicle .
danger Wear the specified protection equipment during the check.
caution A digital multimeter should be used. For details refer to .
(1)Remove the RMCU, and measure at the equipment side.
(2)Resistance between RMCU connector terminal Nos.5 and 6
OK: 1 kΩ or more

Q. Is the check result normal?

Power supply to the RMCU may be suspected. Diagnose the RMCU. Refer to GROUP 54D - Troubleshooting .
Replace the RMCU.