Diagnosis Item 14: Diagnose when the M.U.T.-III cannot receive the data sent by BMU.



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




TROUBLE JUDGEMENT CONDITIONS




PROBABLE CAUSES



  • Damaged harness wires and connectors
  • Power supply circuit malfunction of the BMU
  • Malfunction of the BMU

DIAGNOSIS PROCEDURE


STEP 1. Connector check: C-103 joint connector (CAN2) and C-107 BMU 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 C-103 joint connector (CAN2) and C-107 BMU 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 the joint connector (CAN2) and the BMU connector, and measure at the wiring harness side.
(2)Turn the electric motor switch to the LOCK (OFF) position.
(3)
caution When measuring the resistance, disconnect the negative auxiliary battery terminal. For details refer to .
Ensure that the negative auxiliary battery terminal is disconnected.

(4)Continuity between C-103 joint connector (CAN2) terminal No.9 and C-107 BMU connector terminal No.6
OK: Continuity (2 Ω or less)

(5)Continuity between C-103 joint connector (CAN2) terminal No.20 and C-107 BMU connector terminal No.7
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?

<All the resistances measure 2 Ω or less> Go to Step 3.

<Either or all of the resistances measure more than 2 Ω> Repair the wiring harness between joint connector (CAN2) and the BMU connector.

STEP 3. Resistance measurement at C-107 BMU connector.


caution A digital multimeter should be used. For details refer to .
(1)Remove the BMU, and measure at the equipment side.

(2)Resistance between C-107 BMU connector terminal Nos.6 and 7
OK: 1 kΩ or more

Q. Is the check result normal?

<1 kΩ or more> Power supply to the BMU may be suspected. Diagnose the BMU. Refer to .

<Less than 1 kΩ > Replace the BMU.