Diagnosis Item 2: Diagnose shorts in the power supply to CAN bus line (MAIN). <Vehicles for LHD>



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 JUDGEMENT CONDITIONS


The M.U.T.-III judges the trouble when it is impossible to receive the periodically sent data and the voltage of CAN_H or CAN_L line is more than 4.0 V.

TROUBLESHOOTING HINTS




DIAGNOSIS PROCEDURE


STEP 1. Check the CAN bus lines. Voltage measurement at diagnosis connector.


caution A digital multimeter should be used.
caution The test wiring harness should be used.
note This inspection allows you to check that there is a short to power supply in either CAN_H line or CAN_L line. Thus, in the following steps, check the CAN main bus line that is defective.
(1)Disconnect engine-ECU connector and ETACS-ECU connector, and measure the voltage at the harness side of diagnosis connector.
(2)Connect the negative battery terminal, and turn the ignition switch to the "ON" position.
(3)Voltage between diagnosis connector terminal No.6 (CAN_H) and body earth
OK: 4.0 V or less
(4)Voltage between diagnosis connector terminal No.14 (CAN_L) and body earth
OK: 4.0 V or less
(5)Disconnect the negative battery terminal.

Q. Is the check result normal?

<Both of the measurement results show 4.0 V or less> Go to Step 43.
<Either of CAN_H line or CAN_L line the measurement results show more than 4.0 V> Go to Step 2.

STEP 2. Check the CAN line. Voltage measurement at joint connector (CAN2) and the joint connector (CAN1). Voltage measurement at joint connector (CAN1).


caution A digital multimeter should be used.
caution The test wiring harness should be used.
(1)Disconnect joint connector (CAN1), and measure at the wiring harness side.
(2)Connect the negative battery terminal, and turn the ignition switch to the "ON" position.
(3)Voltage between joint connector (CAN1) terminal No.9 (CAN_H) and body earth
OK: 4.0 V or less
(4)Voltage between joint connector (CAN1) terminal No.20 (CAN_L) and body earth
OK: 4.0 V or less
(5)Disconnect the negative battery terminal.

Q. Is the check result normal?

<4.0 V or less> Go to Step 17.
<More than 4.0 V> Go to Step 3.

STEP 3. Check the CAN line between joint connector (CAN2) and the ETACS-ECU. Voltage measurement at joint connector (CAN2).


caution A digital multimeter should be used.
caution The test wiring harness should be used.
(1)Disconnect joint connector (CAN2), and measure at the wiring harness side.
(2)Connect the negative battery terminal, and turn the ignition switch to the "ON" position.
(3)Voltage between joint connector (CAN2) terminal No.11 (CAN_H) and body earth
OK: 4.0 V or less
(4)Voltage between joint connector (CAN2) terminal No.22 (CAN_L) and body earth
OK: 4.0 V or less
(5)Disconnect the negative battery terminal.
caution Strictly observe the specified wiring harness repair procedure.

Q. Is the check result normal?

YES : <4.0 V or less> Go to Step 4.
NO : <More than 4.0 V> Repair the wiring harness between joint connector (CAN2) and the ETACS-ECU connector.

STEP 4. Check the CAN line between joint connector (CAN2) and the combination meter. Voltage measurement at joint connector (CAN2).


caution A digital multimeter should be used.
caution The test wiring harness should be used.
(1)Disconnect joint connector (CAN2), and measure at the wiring harness side.
(2)Connect the negative battery terminal, and turn the ignition switch to the "ON" position.
(3)Voltage between joint connector (CAN2) terminal No.2 (CAN_H) and body earth
OK: 4.0 V or less
(4)Voltage between joint connector (CAN2) terminal No.13 (CAN_L) and body earth
OK: 4.0 V or less
(5)Disconnect the negative battery terminal.

Q. Is the check result normal?

YES : <4.0 V or less> Go to Step 7.
<More than 4.0 V> Go to Step 5.

STEP 5. M.U.T.-III CAN bus diagnostics [combination meter connector disconnected]


(1)Disconnect combination meter connector, and diagnose by using the M.U.T.-III.

(2)Diagnose CAN bus lines, and check if M.U.T.-III screen is as shown in the illustration.

Q. Does M.U.T.-III screen correspond to the illustration?

Repair the wiring harness between joint connector (CAN2) and the combination meter connector.

Check the combination meter connector, and repair if necessary. If the combination meter connector is in good condition, go to Step 6.

STEP 6. M.U.T.-III CAN bus diagnostics (retest the system)


Diagnose CAN bus lines, and check if M.U.T.-III screen shows normal state.

Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction).
Check the combination meter connector, and repair if necessary. If the combination meter connector is in good condition, replace the combination meter (Refer to GROUP 54A - Combination meter).

STEP 7. Check the CAN line between joint connector (CAN2) and the transfer-ECU. Voltage measurement at joint connector (CAN2).


caution A digital multimeter should be used.
caution The test wiring harness should be used.
(1)Disconnect joint connector (CAN2), and measure at the wiring harness side.
(2)Connect the negative battery terminal, and turn the ignition switch to the "ON" position.
(3)Voltage between joint connector (CAN2) terminal No.4 (CAN_H) and body earth
OK: 4.0 V or less
(4)Voltage between joint connector (CAN2) terminal No.15 (CAN_L) and body earth
OK: 4.0 V or less
(5)Disconnect the negative battery terminal.
caution Strictly observe the specified wiring harness repair procedure.

Q. Is the check result normal?

<4.0 V or less> Go to Step 10.
<More than 4.0 V> Go to Step 8.

STEP 8. M.U.T.-III CAN bus diagnostics [transfer-ECU connector disconnected]


(1)Disconnect transfer-ECU connector, and diagnose by using the M.U.T.-III.

(2)Diagnose CAN bus lines, and check if M.U.T.-III screen is as shown in the illustration.

Q. Does M.U.T.-III screen correspond to the illustration?

Repair the wiring harness between joint connector (CAN2) and the transfer-ECU connector.

Check the transfer-ECU connector, and repair if necessary. If the transfer-ECU connector is in good condition, go to Step 9.

STEP 9. M.U.T.-III CAN bus diagnostics (retest the system)


Diagnose CAN bus lines, and check if M.U.T.-III screen shows normal state.

Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction).
Check the transfer-ECU connector, and repair if necessary. If the transfer-ECU connector is in good condition, replace the transfer-ECU (Refer to GROUP 22A - Transfer-ECU <M/T>, GROUP 23A - Transfer-ECU <A/T>).

STEP 10. Check the CAN line between joint connector (CAN2) and the steering wheel sensor. Voltage measurement at joint connector (CAN2).


caution A digital multimeter should be used.
caution The test wiring harness should be used.
(1)Disconnect joint connector (CAN2), and measure at the wiring harness side.
(2)Connect the negative battery terminal, and turn the ignition switch to the "ON" position.
(3)Voltage between joint connector (CAN2) terminal No.6 (CAN_H) and body earth
OK: 4.0 V or less
(4)Voltage between joint connector (CAN2) terminal No.17 (CAN_L) and body earth
OK: 4.0 V or less
(5)Disconnect the negative battery terminal.

Q. Is the check result normal?

<4.0 V or less> Go to Step 13.
<More than 4.0 V> Go to Step 11.

STEP 11. M.U.T.-III CAN bus diagnostics [Steering wheel sensor connector disconnected]


(1)Disconnect steering wheel sensor connector, and diagnose by using the M.U.T.-III.

(2)Diagnose CAN bus lines, and check if M.U.T.-III screen is as shown in the illustration.

Q. Does M.U.T.-III screen correspond to the illustration?

Check the intermediate connector, and repair if necessary. If the intermediate connector is in good condition, repair the wiring harness between joint connector (CAN2) and the steering wheel sensor connector.

Check the steering wheel sensor connector, and repair if necessary. If the steering wheel sensor connector is in good condition, go to Step 12.

STEP 12. M.U.T.-III CAN bus diagnostics (retest the system)


Diagnose CAN bus lines, and check if M.U.T.-III screen shows normal state.

Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction).
Check the steering wheel sensor connector, and repair if necessary. If the steering wheel sensor connector is in good condition, replace the column switch (integrated with steering wheel sensor) (Refer to GROUP 54A - Column Switch).

STEP 13. Check the CAN line between joint connector (CAN2) and the A/T-ECU. Voltage measurement at joint connector (CAN2).


caution A digital multimeter should be used.
caution The test wiring harness should be used.
(1)Disconnect joint connector (CAN2), and measure at the wiring harness side.
(2)Connect the negative battery terminal, and turn the ignition switch to the "ON" position.
(3)Voltage between joint connector (CAN2) terminal No.1 (CAN_H) and body earth
OK: 4.0 V or less
(4)Voltage between joint connector (CAN2) terminal No.12 (CAN_L) and body earth
OK: 4.0 V or less
(5)Disconnect the negative battery terminal.
caution Strictly observe the specified wiring harness repair procedure.

Q. Is the check result normal?

<4.0 V or less> Go to Step 16.
<More than 4.0 V> Go to Step 14.

STEP 14. M.U.T.-III CAN bus diagnostics [A/T-ECU connector disconnected]


(1)Disconnect A/T-ECU connector, and diagnose by using the M.U.T.-III.

(2)Diagnose CAN bus lines, and check if M.U.T.-III screen is as shown in the illustration.

Q. Does M.U.T.-III screen correspond to the illustration?

Repair the wiring harness between joint connector (CAN2) and the A/T-ECU connector.

Check the A/T-ECU connector, and repair if necessary. If the A/T-ECU connector is in good condition, go to Step 15.

STEP 15. M.U.T.-III CAN bus diagnostics (retest the system)


Diagnose CAN bus lines, and check if M.U.T.-III screen shows normal state.

Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction).
Check the A/T-ECU connector, and repair if necessary. If the A/T-ECU connector is in good condition, replace the A/T-ECU (Refer to GROUP 23A - A/T-ECU).

STEP 16. Check the CAN line between joint connector (CAN2) and the diagnosis connector. Voltage measurement at joint connector (CAN2).


caution A digital multimeter should be used.
caution The test wiring harness should be used.
(1)Disconnect joint connector (CAN2), and measure at the wiring harness side.
(2)Connect the negative battery terminal, and turn the ignition switch to the "ON" position.
(3)Voltage between joint connector (CAN2) terminal No.10 (CAN_H) and body earth
OK: Less than 1.0 V
(4)Voltage between joint connector (CAN2) terminal No.21 (CAN_L) and body earth
OK: Less than 1.0 V
(5)Disconnect the negative battery terminal.
caution Strictly observe the specified wiring harness repair procedure.

Q. Is the check result normal?

<Less than 1.0 V> Repair the wiring harness between joint connector (CAN1) and the joint connector (CAN2).
<1.0 V or more> Repair the diagnosis connector, or the wiring harness between joint connector (CAN2) and the diagnosis connector.

STEP 17. Check the CAN line. Voltage measurement at D-25 intermediate connector.


caution A digital multimeter should be used.
caution The test wiring harness should be used.
(1)Disconnect the intermediate connector, and measure at its female-side intermediate connector (at the front wiring harness side).
(2)Connect the negative battery terminal, and turn the ignition switch to the "ON" position.
(3)Voltage between D-25 intermediate connector terminal No.19 (CAN_H) and body earth
OK: 4.0 V or less
(4)Voltage between D-25 intermediate connector terminal No.18 (CAN_L) and body earth
OK: 4.0 V or less
(5)Disconnect the negative battery terminal.

Q. Is the check result normal?

YES : <4.0 V or less> Go to Step 22.
<More than 4.0 V> Go to Step 18.

STEP 18. Check the CAN line between joint connector (CAN3) and the engine-ECU. Voltage measurement at joint connector (CAN3).


caution A digital multimeter should be used.
caution The test wiring harness should be used.
(1)Disconnect joint connector (CAN3), and measure at the wiring harness side.
(2)Connect the negative battery terminal, and turn the ignition switch to the "ON" position.
(3)Voltage between joint connector (CAN3) terminal No.11 (CAN_H) and body earth
OK: 4.0 V or less
(4)Voltage between joint connector (CAN3) terminal No.22 (CAN_L) and body earth
OK: 4.0 V or less
(5)Disconnect the negative battery terminal.

Q. Is the check result normal?

YES : <4.0 V or less> Go to Step 19.
NO : <More than 4.0 V> Repair the wiring harness between joint connector (CAN3) and the engine-ECU connector.

STEP 19. Check the CAN line between joint connector (CAN3) and the FCM-ECU. Voltage measurement at joint connector (CAN3).


caution A digital multimeter should be used.
caution The test wiring harness should be used.
(1)Disconnect joint connector (CAN3), and measure at the wiring harness side.
(2)Connect the negative battery terminal, and turn the ignition switch to the "ON" position.
(3)Voltage between joint connector (CAN3) terminal No.9 (CAN_H) and body earth
OK: 4.0 V or less
(4)Voltage between joint connector (CAN3) terminal No.20 (CAN_L) and body earth
OK: 4.0 V or less
(5)Disconnect the negative battery terminal.
caution Strictly observe the specified wiring harness repair procedure.

Q. Is the check result normal?

<4.0 V or less> Repair the wiring harness between D-25 intermediate connector and the joint connector (CAN3).
NO : <More than 4.0 V> Go to Step 20.

STEP 20. M.U.T.-III CAN bus diagnostics [FCM-ECU connector disconnected]


(1)Disconnect FCM-ECU connector, and diagnose by using the M.U.T.-III.

(2)Diagnose CAN bus lines, and check if M.U.T.-III screen is as shown in the illustration.

Q. Does M.U.T.-III screen correspond to the illustration?

Repair the wiring harness between joint connector (CAN3) and the FCM-ECU connector.

Check the FCM-ECU connector, and repair if necessary. If the FCM-ECU connector is in good condition, go to Step 21.

STEP 21. M.U.T.-III CAN bus diagnostics (retest the system)


Diagnose CAN bus lines, and check if M.U.T.-III screen shows normal state.

Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction).
Check the FCM-ECU connector, and repair if necessary. If the FCM-ECU connector is in good condition, replace the FCM-ECU (Refer to GROUP 35C - FCM-ECU).

STEP 22. Check the CAN line between joint connector (CAN1) and the SRS-ECU. Voltage measurement at joint connector (CAN1).


caution A digital multimeter should be used.
caution The test wiring harness should be used.
(1)Disconnect joint connector (CAN1), and measure at the wiring harness side.
(2)Connect the negative battery terminal, and turn the ignition switch to the "ON" position.
(3)Voltage between joint connector (CAN1) terminal No.7 (CAN_H) and body earth
OK: 4.0 V or less
(4)Voltage between joint connector (CAN1) terminal No.18 (CAN_L) and body earth
OK: 4.0 V or less
(5)Disconnect the negative battery terminal.
caution Strictly observe the specified wiring harness repair procedure.

Q. Is the check result normal?

YES : <4.0 V or less> Go to Step 25.
<More than 4.0 V> Go to Step 23.

STEP 23. M.U.T.-III CAN bus diagnostics [SRS-ECU connector disconnected]


(1)Disconnect SRS-ECU connector, and diagnose by using the M.U.T.-III.

(2)Diagnose CAN bus lines, and check if M.U.T.-III screen is as shown in the illustration.

Q. Does M.U.T.-III screen correspond to the illustration?

Repair the wiring harness between joint connector (CAN1) and the SRS-ECU connector.

Check the SRS-ECU connector, and repair if necessary. If the SRS-ECU connector is in good condition, go to Step 24.

STEP 24. M.U.T.-III CAN bus diagnostics (retest the system)


Diagnose CAN bus lines, and check if M.U.T.-III screen shows normal state.

Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction).
Check the SRS-ECU connector, and repair if necessary. If the SRS-ECU connector is in good condition, replace the SRS-ECU (Refer to GROUP 52B - SRS-ECU).

STEP 25. Check the CAN line between joint connector (CAN1) and the KOS&OSS-ECU. Voltage measurement at joint connector (CAN1).


caution A digital multimeter should be used.
caution The test wiring harness should be used.
(1)Disconnect joint connector (CAN1), and measure at the wiring harness side.
(2)Connect the negative battery terminal, and turn the ignition switch to the "ON" position.
(3)Voltage between joint connector (CAN1) terminal No.8 (CAN_H) and body earth
OK: 4.0 V or less
(4)Voltage between joint connector (CAN1) terminal No.19 (CAN_L) and body earth
OK: 4.0 V or less
(5)Disconnect the negative battery terminal.

Q. Is the check result normal?

<4.0 V or less> Go to Step 28.
<More than 4.0 V> Go to Step 26.

STEP 26. M.U.T.-III CAN bus diagnostics [KOS&OSS-ECU connector disconnected]


(1)Disconnect KOS&OSS-ECU connector, and diagnose by using the M.U.T.-III.

(2)Diagnose CAN bus lines, and check if M.U.T.-III screen is as shown in the illustration.

Q. Does M.U.T.-III screen correspond to the illustration?

Repair the wiring harness between joint connector (CAN1) and the KOS&OSS-ECU connector.

Check the KOS&OSS-ECU connector, and repair if necessary. If the KOS&OSS-ECU connector is in good condition, go to Step 27.

STEP 27. M.U.T.-III CAN bus diagnostics (retest the system)


Diagnose CAN bus lines, and check if M.U.T.-III screen shows normal state.

Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction).
Check the KOS&OSS-ECU connector, and repair if necessary. If the KOS&OSS-ECU connector is in good condition, replace the KOS&OSS-ECU (Refer to GROUP 42B - KOS&OSS-ECU).

STEP 28. Check the CAN line between joint connector (CAN1) and the ABS-ECU or ASTC-ECU. Voltage measurement at joint connector (CAN1).


caution A digital multimeter should be used.
caution The test wiring harness should be used.
(1)Disconnect joint connector (CAN1), and measure at the wiring harness side.
(2)Connect the negative battery terminal, and turn the ignition switch to the "ON" position.
(3)Voltage between joint connector (CAN1) terminal No.5 (CAN_H) and body earth
OK: 4.0 V or less
(4)Voltage between joint connector (CAN1) terminal No.16 (CAN_L) and body earth
OK: 4.0 V or less
(5)Disconnect the negative battery terminal.

Q. Is the check result normal?

YES : <4.0 V or less> Go to Step 31.
<More than 4.0 V> Go to Step 29.

STEP 29. M.U.T.-III CAN bus diagnostics [ABS-ECU or ASTC-ECU connector disconnected]


(1)Disconnect ABS-ECU or ASTC-ECU connector, and diagnose by using the M.U.T.-III.

(2)Diagnose CAN bus lines, and check if M.U.T.-III screen is as shown in the illustration.

Q. Does M.U.T.-III screen correspond to the illustration?

Check the intermediate connector, and repair if necessary. If the intermediate connector is in good condition, repair the wiring harness between joint connector (CAN1) and the ABS-ECU or ASTC-ECU connector.

Check the ABS-ECU or ASTC-ECU connector, and repair if necessary. If the ABS-ECU or ASTC-ECU connector is in good condition, go to Step 30.

STEP 30. M.U.T.-III CAN bus diagnostics (retest the system)


Diagnose CAN bus lines, and check if M.U.T.-III screen shows normal state.

Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction).
Check the ABS-ECU or ASTC-ECU connector, and repair if necessary. If the ABS-ECU or ASTC-ECU connector is in good condition, replace the ABS-ECU (Refer to GROUP 35B - Hydraulic Unit) or ASTC-ECU (Refer to GROUP 35C - Hydraulic Unit).

STEP 31. Check the CAN line between joint connector (CAN1) and the electric parking brake-ECU. Voltage measurement at joint connector (CAN1).


caution A digital multimeter should be used.
caution The test wiring harness should be used.
(1)Disconnect joint connector (CAN1), and measure at the wiring harness side.
(2)Connect the negative battery terminal, and turn the ignition switch to the "ON" position.
(3)Voltage between joint connector (CAN1) terminal No.2 (CAN_H) and body earth
OK: 4.0 V or less
(4)Voltage between joint connector (CAN1) terminal No.13 (CAN_L) and body earth
OK: 4.0 V or less
(5)Disconnect the negative battery terminal.

Q. Is the check result normal?

<4.0 V or less> Go to Step 34.
<More than 4.0 V> Go to Step 32.

STEP 32. M.U.T.-III CAN bus diagnostics [electric parking brake-ECU connector disconnected]


(1)Disconnect electric parking brake-ECU connector, and diagnose by using the M.U.T.-III.

(2)Diagnose CAN bus lines, and check if M.U.T.-III screen is as shown in the illustration.

Q. Does M.U.T.-III screen correspond to the illustration?

Repair the wiring harness between joint connector (CAN1) and the electric parking brake-ECU connector.

Check the electric parking brake-ECU connector, and repair if necessary. If the electric parking brake-ECU connector is in good condition, go to Step 33.

STEP 33. M.U.T.-III CAN bus diagnostics (retest the system)


Diagnose CAN bus lines, and check if M.U.T.-III screen shows normal state.

Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction).
Check the electric parking brake-ECU connector, and repair if necessary. If the electric parking brake-ECU connector is in good condition, replace the electric parking brake-ECU (Refer to GROUP 36 - Electric Parking Brake-ECU).

STEP 34. Check the CAN line between joint connector (CAN1) and the clearance warning control unit. Voltage measurement at joint connector (CAN1).


caution A digital multimeter should be used.
caution The test wiring harness should be used.
(1)Disconnect joint connector (CAN1), and measure at the wiring harness side.
(2)Connect the negative battery terminal, and turn the ignition switch to the "ON" position.
(3)Voltage between joint connector (CAN1) terminal No.8 (CAN_H) and body earth
OK: 4.0 V or less
(4)Voltage between joint connector (CAN1) terminal No.19 (CAN_L) and body earth
OK: 4.0 V or less

Q. Is the check result normal?

<4.0 V or less> Go to Step 37.
<More than 4.0 V> Go to Step 35.

STEP 35. M.U.T.-III CAN bus diagnostics [Clearance warning control unit connector disconnected]


(1)Disconnect clearance warning control unit connector, and diagnose by using the M.U.T.-III.

(2)Diagnose CAN bus lines, and check if M.U.T.-III screen is as shown in the illustration.

Q. Does M.U.T.-III screen correspond to the illustration?

Repair the wiring harness between joint connector (CAN1) and the clearance warning control unit connector.

Check the clearance warning control unit connector, and repair if necessary. If the clearance warning control unit connector is in good condition, go to Step 36.

STEP 36. M.U.T.-III CAN bus diagnostics (retest the system)


Diagnose CAN bus lines, and check if M.U.T.-III screen shows normal state.

Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction).
Check the clearance warning control unit connector, and repair if necessary. If the clearance warning control unit connector is in good condition, replace the clearance warning control unit (Refer to GROUP 54A - Unintended Acceleration Mitigation System/Blind Spot Warning/Corner Sensor System, Clearance Warning Control Unit).

STEP 37. Check the CAN line between joint connector (CAN1) and the gateway-ECU. Voltage measurement at joint connector (CAN1).


caution A digital multimeter should be used.
caution The test wiring harness should be used.
(1)Disconnect joint connector (CAN1), and measure at the wiring harness side.
(2)Connect the negative battery terminal, and turn the ignition switch to the "ON" position.
(3)Voltage between joint connector (CAN1) terminal No.11 (CAN_H) and body earth
OK: 4.0 V or less
(4)Voltage between joint connector (CAN1) terminal No.22 (CAN_L) and body earth
OK: 4.0 V or less
(5)Disconnect the negative battery terminal.

Q. Is the check result normal?

<4.0 V or less> Go to Step 40.
<More than 4.0 V> Go to Step 38.

STEP 38. M.U.T.-III CAN bus diagnostics [Gateway-ECU connector disconnected]


(1)Disconnect gateway-ECU connector, and diagnose by using the M.U.T.-III.

(2)Diagnose CAN bus lines, and check if M.U.T.-III screen is as shown in the illustration.

Q. Does M.U.T.-III screen correspond to the illustration?

Repair the wiring harness between joint connector (CAN1) and the gateway-ECU connector.

Check the gateway-ECU connector, and repair if necessary. If the gateway-ECU connector is in good condition, go to Step 39.

STEP 39. M.U.T.-III CAN bus diagnostics (retest the system)


Diagnose CAN bus lines, and check if M.U.T.-III screen shows normal state.

Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction).
Check the gateway-ECU connector, and repair if necessary. If the gateway-ECU connector is in good condition, replace the gateway-ECU.

STEP 40. Check the CAN line between joint connector (CAN1) and the e-Call control unit. Voltage measurement at joint connector (CAN1).


caution A digital multimeter should be used.
caution The test wiring harness should be used.
(1)Disconnect joint connector (CAN1), and measure at the wiring harness side.
(2)Connect the negative battery terminal, and turn the ignition switch to the "ON" position.
(3)Voltage between joint connector (CAN1) terminal No.1 (CAN_H) and body earth
OK: 4.0 V or less
(4)Voltage between joint connector (CAN1) terminal No.12 (CAN_L) and body earth
OK: 4.0 V or less
(5)Disconnect the negative battery terminal.

Q. Is the check result normal?

<4.0 V or less> Repair the wiring harness between D-25 intermediate connector and the joint connector (CAN1).
<More than 4.0 V> Go to Step 41.

STEP 41. M.U.T.-III CAN bus diagnostics [e-Call control unit connector disconnected]


(1)Disconnect e-Call control unit connector, and diagnose by using the M.U.T.-III.

(2)Diagnose CAN bus lines, and check if M.U.T.-III screen is as shown in the illustration.

Q. Does M.U.T.-III screen correspond to the illustration?

Repair the wiring harness between joint connector (CAN1) and the e-Call control unit connector.

Check the e-Call control unit connector, and repair if necessary. If the e-Call control unit connector is in good condition, go to Step 42.

STEP 42. M.U.T.-III CAN bus diagnostics (retest the system)


Diagnose CAN bus lines, and check if M.U.T.-III screen shows normal state.

Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction).
Check the e-Call control unit connector, and repair if necessary. If the e-Call control unit connector is in good condition, replace the e-Call control unit (Refer to GROUP 54A - Era-Glonass System, e-Call Control Unit ).

STEP 43. M.U.T.-III CAN bus diagnostics [engine-ECU connector disconnected]


(1)Disconnect engine-ECU connector and diagnose by using the M.U.T.-III.

(2)Diagnose CAN bus lines, and check if M.U.T.-III screen is as shown in the illustration.

Q. Does M.U.T.-III screen correspond to the illustration?

Go to Step 45.

Check the engine-ECU connector, and repair if necessary. If the engine-ECU connector is in good condition, go to Step 44.

STEP 44. M.U.T.-III CAN bus diagnostics (retest the system)


Diagnose CAN bus lines, and check if M.U.T.-III screen shows normal state.

Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction).
Check the engine-ECU connector, and repair if necessary. If the engine-ECU connector is in good condition, replace the engine-ECU (Refer to GROUP 13B - Engine-ECU <6B31>, GROUP 13C - Engine-ECU <4N15> or GROUP 13E - Engine-ECU <4D56>).

STEP 45. M.U.T.-III CAN bus diagnostics [ETACS-ECU connector disconnected]


(1)Disconnect ETACS-ECU connector, and diagnose by using the M.U.T.-III.

(2)Diagnose CAN bus lines, and check if M.U.T.-III screen is as shown in the illustration.

Q. Does M.U.T.-III screen correspond to the illustration?

The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction).

Check the ETACS-ECU connector, and repair if necessary. If the ETACS-ECU connector is in good condition, go to Step 46.

STEP 46. M.U.T.-III CAN bus diagnostics (retest the system)


Diagnose CAN bus lines, and check if M.U.T.-III screen shows normal state.

Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction).
Check the ETACS-ECU connector, and repair if necessary. If the ETACS-ECU connector is in good condition, replace the ETACS-ECU (Refer to GROUP 54A - ETACS, ETACS-ECU).