Diagnosis Item 2: Diagnose shorts in the power supply 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.
  • When the ETACS-ECU of vehicles without KOS is replaced, the encrypted code of the ignition key needs to be registered to the ETACS-ECU. (If the encrypted code is not registered, the engine cannot be started. Register the encrypted code as described in GROUP 54A, Immobilizer System - How to Register Key ID .)

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-C. Voltage 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 power supply 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 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 33.
<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-C. Voltage 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)Connect the negative battery terminal, and turn the ignition switch to the ON position.
(3)Voltage between C-126 intermediate connector terminal No.15 (CAN_H) and body earth
OK: 4.0 V or less
(4)Voltage between C-126 intermediate connector 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?
<4.0 V or less> Go to Step 19.
<More than 4.0 V> Go to Step 3.

STEP 3. Check the CAN-C between joint connector (CAN1) and the engine-ECU. Voltage 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)Connect the negative battery terminal, and turn the ignition switch to the ON position.
(3)Voltage between joint connector (CAN1) terminal No.10 (CAN_H) and body earth
OK: 4.0 V or less
(4)Voltage between joint connector (CAN1) terminal No.21 (CAN_L) and body earth
OK: 4.0 V or less
(5)Disconnect the negative battery terminal.

Q. Is the check result normal?
YES <vehicles without ACC> : <4.0 V or less> Go to Step 7.
YES <vehicles with ACC> : <4.0 V or less> Go to Step 4.
<More than 4.0 V> Repair the wiring harness between joint connector (CAN1) and the engine-ECU connector.

STEP 4. Check the CAN-C between joint connector (CAN1) and the ACC/FCM-ECU. Voltage 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)Connect the negative battery terminal, and turn the ignition switch to the ON position.
(3)Voltage between joint connector (CAN1) terminal No.10 (CAN_H) and body earth
OK: 4.0 V or less
(4)Voltage between joint connector (CAN1) terminal No.21 (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 7.
<More than 4.0 V> 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-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?

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-C between joint connector (CAN1) and the CVT-ECU <CVT> or A/T-ECU <A/T>. Voltage 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)Connect the negative battery terminal, and turn the ignition switch to the ON position.
(3)Voltage between joint connector (CAN1) terminal No.6 (CAN_H) and body earth
OK: 4.0 V or less
(4)Voltage between joint connector (CAN1) 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 10.
<More than 4.0 V> Go to Step 8.

STEP 8. M.U.T.-III CAN bus diagnostics [CVT-ECU <CVT> connector or A/T-ECU <A/T> connector disconnected]
(1)Disconnect CVT-ECU <CVT> connector or A/T-ECU <A/T> 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?

Repair the wiring harness between joint connector (CAN1) and the CVT-ECU <CVT> connector or A/T-ECU <A/T> connector.

Check the CVT-ECU <CVT> connector or A/T-ECU <A/T> connector, and repair if necessary. If the CVT-ECU <CVT> connector or A/T-ECU <A/T> 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 CVT-ECU <CVT> connector or A/T-ECU <A/T> connector, and repair if necessary. If the CVT-ECU <CVT> connector or A/T-ECU <A/T> connector is in good condition, replace the CVT-ECU <CVT> or A/T-ECU <A/T>.

STEP 10. Check the CAN-C between joint connector (CAN1) and the EPS-ECU. Voltage 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)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?
YES <vehicles without AS&G system> : <4.0 V or less> Go to Step 16.
NO <vehicles with AS&G system> : <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 [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.

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

STEP 13. Check the CAN-C between joint connector (CAN1) and the AS&G-ECU. Voltage 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)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.

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 [AS&G-ECU connector disconnected]
(1)Disconnect AS&G-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?

Repair the wiring harness between joint connector (CAN1) and the AS&G-ECU connector.

Check the AS&G-ECU connector, and repair if necessary. If the AS&G-ECU connector is in good condition, go to Step 15.

STEP 15. 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 AS&G-ECU connector, and repair if necessary. If the AS&G-ECU connector is in good condition, replace the AS&G-ECU.

STEP 16. Check the CAN-C between joint connector (CAN1) and the ABS-ECU <vehicles without ASC> or ASC-ECU <vehicles with ASC>. Voltage 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)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> Repair intermediate connector C-126, or the wiring harness between joint connector (CAN1) and the intermediate connector C-126.
<More than 4.0 V> Go to Step 17.

STEP 17. M.U.T.-III CAN bus diagnostics [ABS-ECU <vehicles without ASC> or ASC-ECU <vehicles with ASC> connector disconnected]
(1)Disconnect ABS-ECU <vehicles without ASC> or ASC-ECU <vehicles with ASC> 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?

Repair the wiring harness between joint connector (CAN1) and the ABS-ECU <vehicles without ASC> or ASC-ECU <vehicles with ASC> connector.

Check the ABS-ECU <vehicles without ASC> or ASC-ECU <vehicles with ASC> connector, and repair if necessary. If the ABS-ECU <vehicles without ASC> or ASC-ECU <vehicles with ASC> connector is in good condition, go to Step 18.

STEP 18. 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 ABS-ECU <vehicles without ASC> or ASC-ECU <vehicles with ASC> connector, and repair if necessary. If the ABS-ECU <vehicles without ASC> or ASC-ECU <vehicles with ASC> connector is in good condition, replace the ABS-ECU <vehicles without ASC> or ASC-ECU <vehicles with ASC>.

STEP 19. Check the CAN-C between joint connector (CAN3) <LHD> or joint connector (CAN4) <RHD> and the ETACS-ECU. Voltage 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)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 <LHD>
OK: 4.0 V or less
(4)Voltage between joint connector (CAN3) terminal No.22 (CAN_L) and body earth <LHD>
OK: 4.0 V or less
(5)Voltage between joint connector (CAN4) terminal No.7 (CAN_H) and body earth <RHD>
OK: 4.0 V or less
(6)Voltage between joint connector (CAN4) terminal No.18 (CAN_L) and body earth <RHD>
OK: 4.0 V or less
(7)Disconnect the negative battery terminal.
caution Strictly observe the specified wiring harness repair procedure. For details refer to .

Q. Is the check result normal?
YES <2WD> : <4.0 V or less> Go to Step 23.
YES <4WD> : <4.0 V or less> Go to Step 20.
NO : <More than 4.0 V> Repair the wiring harness between joint connector (CAN3) <LHD> or joint connector (CAN4) <RHD> and the ETACS-ECU connector.

STEP 20. Check the CAN-C between joint connector (CAN3) <LHD> or joint connector (CAN4) <RHD> and the 4WD-ECU. Voltage 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)Connect the negative battery terminal, and turn the ignition switch to the ON position.
(3)Voltage between joint connector (CAN3) terminal No.5 (CAN_H) and body earth <LHD>
OK: 4.0 V or less
(4)Voltage between joint connector (CAN3) terminal No.16 (CAN_L) and body earth <LHD>
OK: 4.0 V or less
(5)Voltage between joint connector (CAN4) terminal No.11 (CAN_H) and body earth <RHD>
OK: 4.0 V or less
(6)Voltage between joint connector (CAN4) terminal No.22 (CAN_L) and body earth <RHD>
OK: 4.0 V or less
(7)Disconnect the negative battery terminal.
caution Strictly observe the specified wiring harness repair procedure. For details refer to .

Q. Is the check result normal?
<4.0 V or less> Go to Step 23.
NO : <More than 4.0 V> Go to Step 21.

STEP 21. M.U.T.-III CAN bus diagnostics [4WD-ECU connector disconnected]
(1)Disconnect 4WD-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?

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 4WD-ECU connector.

Check the 4WD-ECU connector, and repair if necessary. If the 4WD-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 4WD-ECU connector, and repair if necessary. If the 4WD-ECU connector is in good condition, replace the 4WD-ECU.

STEP 23. Check the CAN-C between joint connector (CAN3) <LHD> or joint connector (CAN4) <RHD> and the steering wheel sensor. Voltage 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)Connect the negative battery terminal, and turn the ignition switch to the ON position.
(3)Voltage between joint connector (CAN3) terminal No.6 (CAN_H) and body earth <LHD>
OK: 4.0 V or less
(4)Voltage between joint connector (CAN3) terminal No.17 (CAN_L) and body earth <LHD>
OK: 4.0 V or less
(5)Voltage between joint connector (CAN4) terminal No.8 (CAN_H) and body earth <RHD>
OK: 4.0 V or less
(6)Voltage between joint connector (CAN4) terminal No.19 (CAN_L) and body earth <RHD>
OK: 4.0 V or less
(7)Disconnect the negative battery terminal.
caution Strictly observe the specified wiring harness repair procedure. For details refer to .

Q. Is the check result normal?
YES <vehicles without LDW> : <4.0 V or less> Go to Step 29.
YES <vehicles with LDW> : <4.0 V or less> Go to Step 26.
<More than 4.0 V> Go to Step 24.

STEP 24. 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.

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 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 steering wheel sensor connector, and repair if necessary. If the steering wheel sensor connector is in good condition, replace the steering wheel sensor.

STEP 26. Check the CAN-C between joint connector (CAN3) <LHD> or joint connector (CAN4) <RHD> and the LDW-ECU. Voltage 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)Connect the negative battery terminal, and turn the ignition switch to the ON position.
(3)Voltage between joint connector (CAN3) terminal No.7 (CAN_H) and body earth <LHD>
OK: 4.0 V or less
(4)Voltage between joint connector (CAN3) terminal No.18 (CAN_L) and body earth <LHD>
OK: 4.0 V or less
(5)Voltage between joint connector (CAN4) terminal No.11 (CAN_H) and body earth <RHD>
OK: 4.0 V or less
(6)Voltage between joint connector (CAN4) terminal No.22 (CAN_L) and body earth <RHD>
OK: 4.0 V or less
(7)Disconnect the negative battery terminal.
caution Strictly observe the specified wiring harness repair procedure. For details refer to .

Q. Is the check result normal?
<4.0 V or less> Go to Step 29.
<More than 4.0 V> Go to Step 27.

STEP 27. 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-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?

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

STEP 29. Check the CAN-C between joint connector (CAN3) <LHD> or joint connector (CAN4) <RHD> and the SRS-ECU. Voltage 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)Connect the negative battery terminal, and turn the ignition switch to the ON position.
(3)Voltage between joint connector (CAN3) terminal No.8 (CAN_H) and body earth <LHD>
OK: 4.0 V or less
(4)Voltage between joint connector (CAN3) terminal No.19 (CAN_L) and body earth <LHD>
OK: 4.0 V or less
(5)Voltage between joint connector (CAN4) terminal No.9 (CAN_H) and body earth <RHD>
OK: 4.0 V or less
(6)Voltage between joint connector (CAN4) terminal No.20 (CAN_L) and body earth <RHD>
OK: 4.0 V or less
(7)Disconnect the negative battery terminal.
caution Strictly observe the specified wiring harness repair procedure. For details refer to .

Q. Is the check result normal?
<4.0 V or less> Go to Step 32.
<More than 4.0 V> Go to Step 30.

STEP 30. 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-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?

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 31.

STEP 31. 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 32. Check the CAN-C between joint connector (CAN3) <LHD> or joint connector (CAN4) <RHD> and the diagnosis connector. Voltage 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)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 <LHD>
OK: Less than 1.0 V
(4)Voltage between joint connector (CAN3) terminal No.20 (CAN_L) and body earth <LHD>
OK: Less than 1.0 V
(5)Voltage between joint connector (CAN4) terminal No.10 (CAN_H) and body earth <RHD>
OK: Less than 1.0 V
(6)Voltage between joint connector (CAN4) terminal No.21 (CAN_L) and body earth <RHD>
OK: Less than 1.0 V
(7)Disconnect the negative battery terminal.
caution Strictly observe the specified wiring harness repair procedure. For details refer to .

Q. Is the check result normal?
<Less than 1.0 V> 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.
<1.0 V or more> Repair the diagnosis connector, or the wiring harness between joint connector (CAN3) <LHD> or joint connector (CAN4) <RHD> and the diagnosis connector.

STEP 33. 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 35.

Check the engine-ECU connector, and repair if necessary. If the engine-ECU connector is in good condition, go to Step 34.

STEP 34. 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 35. 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 36.

STEP 36. 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.