Diagnosis Item 3: Diagnose shorts in the earth to CAN-C.



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 less than 1.0 V.

TROUBLESHOOTING HINTS




DIAGNOSIS PROCEDURE


STEP 1. Check the CAN-C. 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-C 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 auxiliary battery terminal. For details refer to .
Ensure that the negative auxiliary 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 27.
<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-C. Resistance measurement at C-126 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 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 auxiliary battery terminal. For details refer to .
Ensure that the negative auxiliary battery terminal is disconnected.
(3)Resistance between C-126 intermediate connector terminal No.15 (CAN_H) and body earth
OK: 1 kΩ or more
(4)Resistance between C-126 intermediate connector terminal No.16 (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-C between joint connector (CAN1) and the engine-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 auxiliary battery terminal. For details refer to .
Ensure that the negative auxiliary 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 (CAN2) terminal No.13 (CAN_L) and body earth
OK: 1 kΩ or more
(5)
caution Strictly observe the specified wiring harness repair procedure. For details refer to .

Q. Is the check result normal?

<1 kΩ or more> Go to Step 7.
NO <vehicles without ACC> : <Less than 1 kΩ > Repair the wiring harness between joint connector (CAN1) and the engine-ECU connector.
NO <vehicles with ACC> : <Less than 1 kΩ> Go to Step 4.

STEP 4. Check the CAN-C between joint connector (CAN2) and the ACC/FCM-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 auxiliary battery terminal. For details refer to .
Ensure that the negative auxiliary battery terminal is disconnected.
(3)Resistance between joint connector (CAN2) terminal No.3 (CAN_H) and body earth
OK: 1 kΩ or more
(4)Resistance between joint connector (CAN2) terminal No.14 (CAN_L) and body earth
OK: 1 kΩ or more
(5)
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 ACC/FCM-ECU connector.
<Less than 1 kΩ > Go to Step 5.

STEP 5. M.U.T.-III CAN bus diagnostics [ACC/FCM-ECU connector disconnected]


(1)Disconnect ACC/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.
caution Strictly observe the specified wiring harness repair procedure. For details refer to .

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

Repair the wiring harness between joint connector (CAN1) and the ACC/FCM-ECU connector.

Check the ACC/FCM-ECU connector, and repair if necessary. If the ACC/FCM-ECU connector is in good condition, go to Step 6.

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


Diagnose CAN-C, 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 ACC/FCM-ECU connector, and repair if necessary. If the ACC/FCM-ECU connector is in good condition, replace the ACC/FCM-ECU.

STEP 7. Check the CAN line between joint connector (CAN1) and the EPS-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 auxiliary battery terminal. For details refer to .
Ensure that the negative auxiliary 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 10.
<Less than 1 kΩ > Go to Step 8.

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


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


(2)Diagnose CAN-C, and check if M.U.T.-III screen is as shown in the illustration.
caution Strictly observe the specified wiring harness repair procedure. For details refer to .

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

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

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

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


Diagnose CAN-C, 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 EPS-ECU connector, and repair if necessary. If the EPS-ECU connector is in good condition, replace the EPS-ECU.

STEP 10. Check the CAN-C between joint connector (CAN1) and the ASC-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 auxiliary battery terminal. For details refer to .
Ensure that the negative auxiliary 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
caution Strictly observe the specified wiring harness repair procedure. For details refer to .

Q. Is the check result normal?

<1 kΩ or more> Repair intermediate connector C-126, or the wiring harness between joint connector (CAN1) and intermediate connector C-126.
<Less than 1 kΩ > Go to Step 11.

STEP 11. M.U.T.-III CAN bus diagnostics [ASC-ECU connector disconnected]


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


(2)Diagnose CAN-C, and check if M.U.T.-III screen is as shown in the illustration.
caution Strictly observe the specified wiring harness repair procedure. For details refer to .

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

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

Check the ASC-ECU connector, and repair if necessary. If the ASC-ECU connector is in good condition, go to Step 12.

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


Diagnose CAN-C, 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 ASC-ECU> connector, and repair if necessary. If the ASC-ECU connector is in good condition, replace the ASC-ECU.

STEP 13. Check CAN line between joint connector (CAN3) <LHD> or joint connector (CAN4) <RHD> and the ETACS-ECU. Resistance measurement at joint connector (CAN3) <LHD> or joint connector (CAN4) <RHD>.


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) <LHD> or joint connector (CAN4) <RHD>, and measure at the wiring harness side.
(2)
caution When measuring the resistance, disconnect the negative auxiliary battery terminal. For details refer to .
Ensure that the negative auxiliary battery terminal is disconnected.
(3)Resistance between joint connector (CAN3) terminal No.11 (CAN_H) and body earth <LHD>
OK: 1 kΩ or more
(4)Resistance between joint connector (CAN3) terminal No.22 (CAN_L) and body earth <LHD>
OK: 1 kΩ or more
(5)Resistance between joint connector (CAN4) terminal No.7 (CAN_H) and body earth <RHD>
OK: 1 kΩ or more
(6)Resistance between joint connector (CAN4) terminal No.18 (CAN_L) and body earth <RHD>
OK: 1 kΩ or more
(7)
caution Strictly observe the specified wiring harness repair procedure. For details refer to .

Q. Is the check result normal?

<1 kΩ or more> Go to Step 14.
NO : <Less than 1 kΩ > Repair the wiring harness between joint connector (CAN3) <LHD> or joint connector (CAN4) <RHD> and the ETACS-ECU connector.

STEP 14. Check the CAN-C between joint connector (CAN3) <LHD> or joint connector (CAN4) <RHD> and the steering wheel sensor. Resistance measurement at joint connector (CAN3) <LHD> or joint connector (CAN4) <RHD>.


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) <LHD> or joint connector (CAN4) <RHD>, and measure at the wiring harness side.
(2)
caution When measuring the resistance, disconnect the negative auxiliary battery terminal. For details refer to .
Ensure that the negative auxiliary battery terminal is disconnected.
(3)Resistance between joint connector (CAN3) terminal No.6 (CAN_H) and body earth <LHD>
OK: 1 kΩ or more
(4)Resistance between joint connector (CAN3) terminal No.17 (CAN_L) and body earth <LHD>
OK: 1 kΩ or more
(5)Resistance between joint connector (CAN4) terminal No.8 (CAN_H) and body earth <RHD>
OK: 1 kΩ or more
(6)Resistance between joint connector (CAN4) terminal No.19 (CAN_L) and body earth <RHD>
OK: 1 kΩ or more
(7)
caution Strictly observe the specified wiring harness repair procedure. For details refer to .

Q. Is the check result normal?

YES <vehicles without LDW> : <1 kΩ or more> Go to Step 20.
YES <vehicles with LDW> : <1 kΩ or more> Go to Step 17.
<Less than 1 kΩ > Go to Step 15.

STEP 15. 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-C, and check if M.U.T.-III screen is as shown in the illustration.
caution Strictly observe the specified wiring harness repair procedure. For details refer to .

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

Repair the wiring harness between joint connector (CAN3) <LHD> or joint connector (CAN4) <RHD> 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 16.

STEP 16.M.U.T.-III CAN bus diagnostics (retest the system)


Diagnose CAN-C, 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 steering wheel sensor.

STEP 17. Check the CAN-C between joint connector (CAN3) <LHD> or joint connector (CAN4) <RHD> and the LDW-ECU. Resistance measurement at joint connector (CAN3) <LHD> or joint connector (CAN4) <RHD>.


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) <LHD> or joint connector (CAN4) <RHD>, and measure at the wiring harness side.
(2)
caution When measuring the resistance, disconnect the negative auxiliary battery terminal. For details refer to .
Ensure that the negative auxiliary battery terminal is disconnected.
(3)Resistance between joint connector (CAN3) terminal No.7 (CAN_H) and body earth <LHD>
OK: 1 kΩ or more
(4)Resistance between joint connector (CAN3) terminal No.18 (CAN_L) and body earth <LHD>
OK: 1 kΩ or more
(5)Resistance between joint connector (CAN4) terminal No.11 (CAN_H) and body earth <RHD>
OK: 1 kΩ or more
(6)Resistance between joint connector (CAN4) terminal No.22 (CAN_L) and body earth <RHD>
OK: 1 kΩ or more

Q. Is the check result normal?

<1 kΩ or more> Go to Step 20.
<Less than 1 kΩ > Go to Step 18.

STEP 18. M.U.T.-III CAN bus diagnostics [LDW-ECU connector disconnected]


(1)Disconnect LDW-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.
caution Strictly observe the specified wiring harness repair procedure. For details refer to .

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 (CAN3) <LHD> or joint connector (CAN4) <RHD> and the LDW-ECU connector.

Check the LDW-ECU connector, and repair if necessary. If the LDW-ECU connector is in good condition, go to Step 19.

STEP 19. M.U.T.-III CAN bus diagnostics (retest the system)


Diagnose CAN-C, 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 LDW-ECU connector, and repair if necessary. If the LDW-ECU connector is in good condition, replace the LDW-ECU.

STEP 20. Check the CAN-C between joint connector (CAN3) <LHD> or joint connector (CAN4) <RHD> and the PHEV-ECU. Resistance measurement at joint connector (CAN3) <LHD> or joint connector (CAN4) <RHD>.


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) <LHD> or joint connector (CAN4) <RHD>, and measure at the wiring harness side.
(2)
caution When measuring the resistance, disconnect the negative auxiliary battery terminal. For details refer to .
Ensure that the negative auxiliary battery terminal is disconnected.
(3)Resistance between joint connector (CAN3) terminal No.11 (CAN_H) and body earth <LHD>
OK: 1 kΩ or more
(4)Resistance between joint connector (CAN3) terminal No.22 (CAN_L) and body earth <LHD>
OK: 1 kΩ or more
(5)Resistance between joint connector (CAN4) terminal No.6 (CAN_H) and body earth <RHD>
OK: 1 kΩ or more
(6)Resistance between joint connector (CAN4) terminal No.17 (CAN_L) and body earth <RHD>
OK: 1 kΩ or more

Q. Is the check result normal?

<1 kΩ or more> Go to Step 23.
<Less than 1 kΩ> Go to Step 21.

STEP 21. M.U.T.-III CAN bus diagnostics [PHEV-ECU connector disconnected]


(1)Disconnect PHEV-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.
caution Strictly observe the specified wiring harness repair procedure. For details refer to .

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 (CAN3) <LHD> or joint connector (CAN4) <RHD> and the PHEV-ECU connector.

Check the PHEV-ECU connector, and repair if necessary. If the PHEV-ECU connector is in good condition, go to Step 22.

STEP 22. M.U.T.-III CAN bus diagnostics (retest the system)


Diagnose CAN-C, 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 PHEV-ECU connector, and repair if necessary. If the PHEV-ECU connector is in good condition, replace the PHEV-ECU.

STEP 23. Check the CAN-C between joint connector (CAN3) <LHD> or joint connector (CAN4) <RHD> and the SRS-ECU. Resistance measurement at joint connector (CAN3) <LHD> or joint connector (CAN4) <RHD>.


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) <LHD> or joint connector (CAN4) <RHD>, and measure at the wiring harness side.
(2)
caution When measuring the resistance, disconnect the negative auxiliary battery terminal. For details refer to .
Ensure that the negative battery terminal is disconnected.
(3)Resistance between joint connector (CAN3) terminal No.8 (CAN_H) and body earth <LHD>
OK: 1 kΩ or more
(4)Resistance between joint connector (CAN3) terminal No.19 (CAN_L) and body earth <LHD>
OK: 1 kΩ or more
(5)Resistance between joint connector (CAN4) terminal No.9 (CAN_H) and body earth <RHD>
OK: 1 kΩ or more
(6)Resistance between joint connector (CAN4) terminal No.20 (CAN_L) and body earth <RHD>
OK: 1 kΩ or more

Q. Is the check result normal?

<1 kΩ or more> Go to Step 26.
<Less than 1 kΩ > Go to Step 24.

STEP 24. 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.
caution Strictly observe the specified wiring harness repair procedure. For details refer to .

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

Repair the wiring harness between joint connector (CAN3) <LHD> or joint connector (CAN4) <RHD> 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 25.

STEP 25. M.U.T.-III CAN bus diagnostics (retest the system)


Diagnose CAN-C, 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.

STEP 26. Check the CAN-C between joint connector (CAN3) <LHD> or joint connector (CAN4) <RHD> and the diagnosis connector. Resistance measurement at joint connector (CAN3) <LHD> or joint connector (CAN4) <RHD>.


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) <LHD> or joint connector (CAN4) <RHD>, and measure at the wiring harness side.
(2)
caution When measuring the resistance, disconnect the negative auxiliary battery terminal. For details refer to .
Ensure that the negative auxiliary battery terminal is disconnected.
(3)Resistance between joint connector (CAN3) terminal No.9 (CAN_H) and body earth <LHD>
OK: 1 kΩ or more
(4)Resistance between joint connector (CAN3) terminal No.20 (CAN_L) and body earth <LHD>
OK: 1 kΩ or more
(5)Resistance between joint connector (CAN4) terminal No.10 (CAN_H) and body earth <RHD>
OK: 1 kΩ or more
(6)Resistance between joint connector (CAN4) terminal No.21 (CAN_L) and body earth <RHD>
OK: 1 kΩ or more
(7)
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 intermediate connector C-126, or the wiring harness between joint connector (CAN3) <LHD> or joint connector (CAN4) <RHD> and the intermediate connector C-126.
<Less than 1 kΩ > Repair the diagnosis connector, or the wiring harness between joint connector (CAN3) <LHD> or joint connector (CAN4) <RHD> and the diagnosis connector.

STEP 27. 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-C, 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 29

Check the engine-ECU connector, and repair if necessary. If the engine-ECU connector is in good condition, go to Step 28.

STEP 28. M.U.T.-III CAN bus diagnostics (retest the system)


Diagnose CAN-C, 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.

STEP 29. 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-C, 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 30.

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


Diagnose CAN-C, 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.