Diagnosis Item 3: Diagnose shorts in the earth to CAN bus line (MAIN).

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 resistance of CAN_H or CAN_L line is less than 1.0 V.

TROUBLESHOOTING HINTS

Malfunction of the wiring harness
Malfunction of the connector
Malfunction of the ETACS-ECU
Malfunction of the combination meter
Malfunction of the gateway-ECU <Vehicles with automatic A/C>
Malfunction of the transfer-ECU <Vehicles with 4WD>
Malfunction of the steering wheel sensor <Vehicles with ASTC>
Malfunction of the KOS&OSS-ECU <Vehicles with keyless operation system>
Malfunction of the SRS-ECU
Malfunction of the ABS-ECU <Vehicles without ASTC> or ASTC-ECU <Vehicles with ASTC>
Malfunction of the A/T-ECU <Vehicles with A/T>
Malfunction of the engine-ECU
Malfunction of the electric parking brake ECU
Malfunction of the clearance warning control unit <Vehicles with ultrasonic misacceleration mitigation, blind spot warning or corner sensor system>
FCM-ECU <Vehicles with forward collision mitigation system>

DIAGNOSIS PROCEDURE

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

caution

A digital multimeter should be used. For details refer to

caution

The test wiring harness should be used. For details refer to

note

This inspection allows you to check that there is a short to earth in either CAN_H line or CAN_L line. Thus, in the following steps, check the CAN bus line that is defective.

(1)Disconnect engine-ECU connector and ETACS-ECU connector, and measure the resistance at harness side of diagnosis connector.

(2)

caution

When measuring the resistance, disconnect the negative battery terminal. For details refer to

Ensure that the negative battery terminal is disconnected.

(3)Resistance between diagnosis connector terminal No.6 (CAN_H) and body earth.
OK: 1 kΩ or more

(4)Resistance between diagnosis connector terminal No.14 (CAN_L) and body earth.
OK: 1 kΩ or more

Q. Is the check result normal?

	<Both of the measurement results show 1 kΩ or more> Go to Step 40.

	<Either of CAN_H line or CAN_L line the measurement results show less than 1 kΩ> Go to Step 2.

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

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 (CAN1), and measure at the wiring harness side.

(2)

caution

When measuring the resistance, disconnect the negative battery terminal. For details refer to

Ensure that the negative battery terminal is disconnected.

(3)Resistance between joint connector (CAN1) terminal No.10 (CAN_H) and body earth.
OK: 1 kΩ or more

(4)Resistance between joint connector (CAN1) terminal No.21 (CAN_L) and body earth.
OK: 1 kΩ or more

Q. Is the check result normal?

	<1 kΩ or more> Go to Step 13.

	<Less than 1 kΩ > Go to Step 3.

STEP 3. Check the CAN line between joint connector (CAN2) and the ETACS-ECU. Resistance measurement at 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 joint connector (CAN2), and measure at the wiring harness side.

(2)

caution

When measuring the resistance, disconnect the negative battery terminal. For details refer to

Ensure that the negative battery terminal is disconnected.

(3)Resistance between joint connector (CAN2) terminal No.11 (CAN_H) and body earth.
OK: 1 kΩ or more

(4)Resistance between joint connector (CAN2) terminal No.22 (CAN_L) and body earth.
OK: 1 kΩ or more

caution

Strictly observe the specified wiring harness repair procedure. For details refer to

Q. Is the check result normal?

	YES : <1 kΩ or more> Go to Step 4.

	NO : <Less than 1 kΩ > 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 KOS&OSS-ECU. Resistance measurement at 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 joint connector (CAN2), and measure at the wiring harness side.

(2)

caution

When measuring the resistance, disconnect the negative battery terminal. For details refer to

Ensure that the negative battery terminal is disconnected.

(3)Resistance between joint connector (CAN2) terminal No.9 (CAN_H) and body earth.
OK: 1 kΩ or more

(4)Resistance between joint connector (CAN2) terminal No.20 (CAN_L) and body earth.
OK: 1 kΩ or more

Q. Is the check result normal?

	<1 kΩ or more> Go to Step 7.

	<Less than 1 kΩ > Go to Step 5.

STEP 5. 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 (CAN2) 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 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 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 7. Check the CAN line between joint connector (CAN2) and the SRS-ECU. Resistance measurement at 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 joint connector (CAN2), and measure at the wiring harness side.

(2)

caution

When measuring the resistance, disconnect the negative battery terminal. For details refer to

Ensure that the negative battery terminal is disconnected.

(3)Resistance between joint connector (CAN2) terminal No.6 (CAN_H) and body earth.
OK: 1 kΩ or more

(4)Resistance between joint connector (CAN2) terminal No.17 (CAN_L) and body earth.
OK: 1 kΩ or more

caution

Strictly observe the specified wiring harness repair procedure. For details refer to

Q. Is the check result normal?

	YES : <1 kΩ or more> Go to Step 10.

	<Less than 1 kΩ > Go to Step 8.

STEP 8. 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 (CAN2) 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 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 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 10. Check the CAN line between joint connector (CAN2) and the A/T-ECU. Resistance measurement at 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 joint connector (CAN2), and measure at the wiring harness side.

(2)

caution

When measuring the resistance, disconnect the negative battery terminal. For details refer to

Ensure that the negative battery terminal is disconnected.

(3)Resistance between joint connector (CAN2) terminal No.1 (CAN_H) and body earth.
OK: 1 kΩ or more

(4)Resistance between joint connector (CAN2) terminal No.12 (CAN_L) and body earth.
OK: 1 kΩ or more

caution

Strictly observe the specified wiring harness repair procedure. For details refer to

Q. Is the check result normal?

	<1 kΩ or more> Repair the wiring harness between joint connector (CAN2) and the joint connector (CAN1).

	<Less than 1 kΩ > Go to Step 11.

STEP 11. 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 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 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 13. Check the CAN line. Resistance measurement at D-26 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 intermediate connector, and measure at its female-side intermediate connector (at the front wiring harness side).

(2)

caution

When measuring the resistance, disconnect the negative battery terminal. For details refer to

Ensure that the negative battery terminal is disconnected.

(3)Resistance between D-26 intermediate connector terminal No.19 (CAN_H) and body earth.
OK: 1 kΩ or more

(4)Resistance between D-26 intermediate connector terminal No.18 (CAN_L) and body earth.
OK: 1 kΩ or more

Q. Is the check result normal?

	YES : <1 kΩ or more> Go to Step 18.

	<Less than 1 kΩ > Go to Step 14.

STEP 14. Check the CAN line between joint connector (CAN3) and the engine-ECU. Resistance measurement at 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 joint connector (CAN3), and measure at the wiring harness side.

(2)

caution

When measuring the resistance, disconnect the negative battery terminal. For details refer to

Ensure that the negative battery terminal is disconnected.

(3)Resistance between joint connector (CAN3) terminal No.11 (CAN_H) and body earth.
OK: 1 kΩ or more

(4)Resistance between joint connector (CAN3) terminal No.22 (CAN_L) and body earth.
OK: 1 kΩ or more

Q. Is the check result normal?

	YES : <1 kΩ or more> Go to Step 15.

	NO : <Less than 1 kΩ > Repair the wiring harness between joint connector (CAN3) and the engine-ECU connector.

STEP 15. Check the CAN line between joint connector (CAN3) and the FCM-ECU. Resistance measurement at 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 joint connector (CAN3), and measure at the wiring harness side.

(2)

caution

When measuring the resistance, disconnect the negative battery terminal. For details refer to

Ensure that the negative battery terminal is disconnected.

(3)Resistance between joint connector (CAN3) terminal No.9 (CAN_H) and body earth.
OK: 1 kΩ or more

(4)Resistance between joint connector (CAN3) terminal No.20 (CAN_L) and body earth.
OK: 1 kΩ or more

caution

Strictly observe the specified wiring harness repair procedure. For details refer to

Q. Is the check result normal?

	<1 kΩ or more> Repair the wiring harness between D-26 intermediate connector and the joint connector (CAN3).

	NO : <Less than 1 kΩ > Go to Step 16.

STEP 16. 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 17.

STEP 17. 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 18. Check the CAN line between joint connector (CAN1) and the transfer-ECU. Resistance measurement at joint connector (CAN1).

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 (CAN1), and measure at the wiring harness side.

(2)

caution

When measuring the resistance, disconnect the negative battery terminal. For details refer to

Ensure that the negative battery terminal is disconnected.

(3)Resistance between joint connector (CAN1) terminal No.4 (CAN_H) and body earth.
OK: 1 kΩ or more

(4)Resistance between joint connector (CAN1) terminal No.15 (CAN_L) and body earth.
OK: 1 kΩ or more

Q. Is the check result normal?

	<1 kΩ or more> Go to Step 21.

	<Less than 1 kΩ > Go to Step 19.

STEP 19. 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 (CAN1) 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 20.

STEP 20. 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 23A - Transfer-ECU ).

STEP 21. Check the CAN line between joint connector (CAN1) and the electric parking brake ECU. Resistance measurement at joint connector (CAN1).

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 (CAN1), and measure at the wiring harness side.

(2)

caution

When measuring the resistance, disconnect the negative battery terminal. For details refer to

Ensure that the negative battery terminal is disconnected.

(3)Resistance between joint connector (CAN1) terminal No.2 (CAN_H) and body earth.
OK: 1 kΩ or more

(4)Resistance between joint connector (CAN1) terminal No.13 (CAN_L) and body earth.
OK: 1 kΩ or more

Q. Is the check result normal?

	<1 kΩ or more> Go to Step 24.

	<Less than 1 kΩ > Go to Step 22.

STEP 22. 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 23.

STEP 23. 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 24. Check the CAN line between joint connector (CAN1) and the ABS-ECU or ASTC-ECU. Resistance measurement at joint connector (CAN1).

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 (CAN1), and measure at the wiring harness side.

(2)

caution

When measuring the resistance, disconnect the negative battery terminal. For details refer to

Ensure that the negative battery terminal is disconnected.

(3)Resistance between joint connector (CAN1) terminal No.3 (CAN_H) and body earth.
OK: 1 kΩ or more

(4)Resistance between joint connector (CAN1) terminal No.14 (CAN_L) and body earth.
OK: 1 kΩ or more

Q. Is the check result normal?

	YES : <1 kΩ or more> Go to Step 27.

	<Less than 1 kΩ > Go to Step 25.

STEP 25. 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 26.

STEP 26. 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 27. Check the CAN line between joint connector (CAN1) and the steering wheel sensor. Resistance measurement at joint connector (CAN1).

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 (CAN1), and measure at the wiring harness side.

(2)

caution

When measuring the resistance, disconnect the negative battery terminal. For details refer to

Ensure that the negative battery terminal is disconnected.

(3)Resistance between joint connector (CAN1) terminal No.7 (CAN_H) and body earth.
OK: 1 kΩ or more

(4)Resistance between joint connector (CAN1) terminal No.18 (CAN_L) and body earth.
OK: 1 kΩ or more

Q. Is the check result normal?

	<1 kΩ or more> Go to Step 30.

	<Less than 1 kΩ > Go to Step 28.

STEP 28. 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 steering wheel sensor connector, and repair if necessary. If the steering wheel sensor connector is in good condition, go to Step 29.

STEP 29. 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 30. Check the CAN line between joint connector (CAN1) and the combination meter. Resistance measurement at joint connector (CAN1).

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 (CAN1), and measure at the wiring harness side.

(2)

caution

When measuring the resistance, disconnect the negative battery terminal. For details refer to

Ensure that the negative battery terminal is disconnected.

(3)Resistance between joint connector (CAN1) terminal No.5 (CAN_H) and body earth.
OK: 1 kΩ or more

(4)Resistance between joint connector (CAN1) terminal No.16 (CAN_L) and body earth.
OK: 1 kΩ or more

Q. Is the check result normal?

	YES : <1 kΩ or more> Go to Step 33.

	<Less than 1 kΩ > Go to Step 31.

STEP 31. 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 (CAN1) 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 32.

STEP 32. 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 33. Check the CAN line between joint connector (CAN1) and the clearance warning control unit. Resistance measurement at joint connector (CAN1).

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 (CAN1), and measure at the wiring harness side.

(2)

caution

When measuring the resistance, disconnect the negative battery terminal. For details refer to

Ensure that the negative battery terminal is disconnected.

(3)Resistance between joint connector (CAN1) terminal No.8 (CAN_H) and body earth.
OK: 1 kΩ or more

(4)Resistance between joint connector (CAN1) terminal No.19 (CAN_L) and body earth.
OK: 1 kΩ or more

Q. Is the check result normal?

	<1 kΩ or more> Go to Step 36.

	<Less than 1 kΩ > Go to Step 34.

STEP 34. 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 35.

STEP 35. 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 36. Check the CAN line between joint connector (CAN1) and the gateway-ECU. Resistance measurement at joint connector (CAN1).

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 (CAN1), and measure at the wiring harness side.

(2)

caution

When measuring the resistance, disconnect the negative battery terminal. For details refer to

Ensure that the negative battery terminal is disconnected.

(3)Resistance between joint connector (CAN1) terminal No.9 (CAN_H) and body earth.
OK: 1 kΩ or more

(4)Resistance between joint connector (CAN1) terminal No.20 (CAN_L) and body earth.
OK: 1 kΩ or more

Q. Is the check result normal?

	<1 kΩ or more> Go to Step 39.

	<Less than 1 kΩ > Go to Step 37.

STEP 37. 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 38.

STEP 38. 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 (Refer to ).

STEP 39. Check the CAN line between joint connector (CAN1) and the diagnosis connector. Resistance measurement at joint connector (CAN1).

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 (CAN1), and measure at the wiring harness side.

(2)

caution

When measuring the resistance, disconnect the negative battery terminal. For details refer to

Ensure that the negative battery terminal is disconnected.

(3)Resistance between joint connector (CAN1) terminal No.6 (CAN_H) and body earth.
OK: 1 kΩ or more

(4)Resistance between joint connector (CAN1) terminal No.17 (CAN_L) and body earth.
OK: 1 kΩ or more

caution

Strictly observe the specified wiring harness repair procedure. For details refer to

Q. Is the check result normal?

	<1 kΩ or more> Repair the wiring harness between D-26 intermediate connector and the joint connector (CAN1).

	<Less than 1 kΩ> Repair the diagnosis connector, or the wiring harness between joint connector (CAN1) and the diagnosis connector.

STEP 40. 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 42.

Check the engine-ECU connector, and repair if necessary. If the engine-ECU connector is in good condition, go to Step 41.

STEP 41. 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 13A - Engine-ECU <4G64>, GROUP 13B - Engine-ECU <6B31 or GROUP 13C - Engine-ECU <4N15>).

STEP 42. 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 43.

STEP 43. 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 ).