Diagnosis Item 12: Diagnose the lines between the joint connectors (CAN4 and CAN3).



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 "diagnose the lines between the joint connectors (CAN4 and CAN3)" when the M.U.T.-III checks the periodically sent data from each ECU and cannot receive the engine-ECU data.

TROUBLE JUDGEMENT CONDITIONS


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

PROBABLE CAUSE


Damaged harness wires and connectors

DIAGNOSIS PROCEDURE


STEP 1. Connector check: joint connector (CAN4) and joint connector (CAN3)


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 (CAN4) and joint connector (CAN3).


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 (CAN4) and the joint connector (CAN3), and measure at the wiring harness side.
(2)Turn the ignition switch to the LOCK (OFF) position.
(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 (CAN4) terminal No.11 and joint connector (CAN3) terminal No.4
OK: Continuity (2 Ω or less)
(5)Continuity between joint connector (CAN4) terminal No.22 and joint connector (CAN3) terminal No.15
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> Follow diagnosis item 13, 14, 15, 16, 17, 18, 19, 20, 21 and 22. Refer to .
NO : <Either or all of the resistances measure more than 2 Ω> Repair the wiring harness between joint connector (CAN4) and joint connector (CAN3).