Diagnosis Item 14: Diagnose the lines between the joint connectors (CAN1 and CAN2)


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.


TROUBLE JUDGMENT


If the M.U.T.-III cannot receive any signal from the ABS-ECU and the engine-ECU <M/T> or engine-A-M/T-ECU <Automated manual transmission>, CAN bus line connector(s) are broken or an open circuit has occurred.

COMMENTS ON TROUBLE SYMPTOM


The CAN bus line wire or connectors may have loose, corroded, or damage terminals, or terminals pushed back in the connector.

POSSIBLE CAUSES



DIAGNOSIS PROCEDURE

STEP 1. Connector check: B-03 joint connector (CAN1) and B-118 intermediate 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 is not damaged.

Q. Are the check results normal?

Go to Step 2.

Repair a defective connector or replace the joint connector.

STEP 2. Resistance measurement at B-03 joint connector (CAN1) and B-118 intermediate 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 (CAN1) and the intermediate connector, and measure at the wiring harness side.
(2)Ignition switch: OFF (LOCK)
(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 B-118 intermediate connector terminal No.12 and B-03 joint connector (CAN1) terminal No.22
OK: 2 Ω or less

(5)Continuity between B-118 intermediate connector terminal No.13 and B-03 joint connector (CAN1) terminal No.11
OK: 2 Ω or less
caution Strictly observe the specified wiring harness repair procedure. For details refer to .

Q. Are the check results normal?

<All the voltages 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 (CAN1) and the intermediate connector.

STEP 3. Connector check: B-107 joint connector (CAN2)


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 is not damaged.

Q. Is the check result normal?

Go to Step 4.

Repair a defective connector or replace the joint connector (front wiring harness assembly).

STEP 4. Resistance measurement at B-118 intermediate connector and B-107 joint connector (CAN2).
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 intermediate connector, and measure at the wiring harness side.
(2)Ignition switch: OFF (LOCK)
(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 B-107 joint connector (CAN2) terminal No.9 and B-118 intermediate connector terminal No.13
OK: 2 Ω or less

(5)Continuity between B-107 joint connector (CAN2) terminal No.20 and B-118 intermediate connector terminal No.12
OK: 2 Ω or less
caution Strictly observe the specified wiring harness repair procedure. For details refer to .

Q. Are the check results normal?

<All the resistances measure 2 Ω or less> Follow diagnosis item 15 "Diagnose the lines from the main bus line to the engine-ECU <M/T> or engine-A-M/T-ECU <Automated manual transmission>" (Refer to ), diagnosis item 16 "Diagnose the lines between CAN main bus line and the ABS-ECU (Refer to ) <vehicles without active stability control system> or diagnosis item 17 "Diagnose the lines between CAN main bus line and the TCL/ASC-ECU" (Refer to ) <vehicles with TCL/ASC system>.

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