Diagnosis Item 2: Diagnose shorts in the power supply to CAN bus line. <Vehicles for General Export>


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. For details refer to service precautions.
  • The test wiring harness should be used. For details refer to service precautions.
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 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 27.
<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 C-213 intermediate connector.
caution
  • A digital multimeter should be used. For details refer to service precautions.
  • The test wiring harness should be used. For details refer to service precautions.
(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-213 intermediate connector terminal No. 1 (CAN_H) and body earth.
OK: 4.0 V or less
(4)Voltage between C-213 intermediate connector terminal No. 2 (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 3.

STEP 3. Check the CAN line between joint connector (CAN2) and the engine-ECU. Voltage measurement at joint connector (CAN2).
caution
  • A digital multimeter should be used. For details refer to service precautions.
  • The test wiring harness should be used. For details refer to service precautions.
  • Strictly observe the specified wiring harness repair procedure. For details refer to service precautions.
(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.

Q. Is the check result normal?
YES <CVT> : <4.0 V or less> Go to Step 4.
YES <M/T (Vehicles with ABS)> : <4.0 V or less> Go to Step 7.
YES <M/T (Vehicles without ABS)> : <4.0 V or less> Go to Step 10.
NO : <More than 4.0 V> Repair the wiring harness between joint connector (CAN2) and the engine-ECU connector.

STEP 4. Check the CAN line between joint connector (CAN2) and the CVT-ECU. Voltage measurement at joint connector (CAN2). <CVT>
caution
  • A digital multimeter should be used. For details refer to service precautions.
  • The test wiring harness should be used. For details refer to service precautions.
(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. 7 (CAN_H) and body earth.
OK: 4.0 V or less
(4)Voltage between joint connector (CAN2) 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 <Vehicles with ABS> : <4.0 V or less> Go to Step 7.
YES <Vehicles without ABS> : <4.0 V or less> Go to Step 10.
<More than 4.0 V> Go to Step 5.

STEP 5. M.U.T.-III CAN bus diagnostics [CVT-ECU connector disconnected]. <CVT>
caution Strictly observe the specified wiring harness repair procedure. For details refer to service precautions.
(1)Disconnect CVT-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 (CAN2) and the CVT-ECU connector.

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

STEP 6. M.U.T.-III CAN bus diagnostics (retest the system). <CVT>
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 CVT-ECU connector, and repair if necessary. If the CVT-ECU connector is in good condition, replace the CVT-ECU.

STEP 7. Check the CAN line between joint connector (CAN2) and the ABS-ECU. Voltage measurement at joint connector (CAN2). <Vehicles with ABS>
caution
  • A digital multimeter should be used. For details refer to service precautions.
  • The test wiring harness should be used. For details refer to service precautions.
(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: 4.0 V or less
(4)Voltage between joint connector (CAN2) 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 10.
<More than 4.0 V> Go to Step 8.

STEP 8. M.U.T.-III CAN bus diagnostics [ABS-ECU connector disconnected]. <Vehicles with ABS>
caution Strictly observe the specified wiring harness repair procedure. For details refer to service precautions.
(1)Disconnect ABS-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 ABS-ECU connector.

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

STEP 9. M.U.T.-III CAN bus diagnostics (retest the system). <Vehicles with ABS>
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 connector, and repair if necessary. If the ABS-ECU connector is in good condition, replace the ABS-ECU.

STEP 10. Check the CAN line between joint connector (CAN2) and the EPS-ECU. Voltage measurement at joint connector (CAN2).
caution
  • A digital multimeter should be used. For details refer to service precautions.
  • The test wiring harness should be used. For details refer to service precautions.
  • Strictly observe the specified wiring harness repair procedure. For details refer to service precautions.
(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. 8 (CAN_H) and body earth.
OK: 4.0 V or less
(4)Voltage between joint connector (CAN2) 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> Repair intermediate connector C-213, or the wiring harness between joint connector (CAN2) and the intermediate connector C-213.
<More than 4.0 V> Go to Step 11.

STEP 11. M.U.T.-III CAN bus diagnostics [EPS-ECU connector disconnected].
caution Strictly observe the specified wiring harness repair procedure. For details refer to service precautions.
(1)Disconnect EPS-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 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 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 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 line between joint connector (CAN1) and the ETACS-ECU. Voltage measurement at joint connector (CAN1).
caution
  • A digital multimeter should be used. For details refer to service precautions.
  • The test wiring harness should be used. For details refer to service precautions.
  • Strictly observe the specified wiring harness repair procedure. For details refer to service precautions.
(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 with KOS> : <4.0 V or less> Go to Step 14.
YES <Vehicles without KOS> : <4.0 V or less> Go to Step 17.
NO : <More than 4.0 V> Repair the wiring harness between joint connector (CAN1) and the ETACS-ECU connector.

STEP 14. Check the CAN line between joint connector (CAN1) and the KOS&OSS-ECU. Voltage measurement at joint connector (CAN1). <Vehicles with KOS>
caution
  • A digital multimeter should be used. For details refer to service precautions.
  • The test wiring harness should be used. For details refer to service precautions.
(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. <LHD>
OK: 4.0 V or less
(4)Voltage between joint connector (CAN1) terminal No. 22 (CAN_L) and body earth. <LHD>
OK: 4.0 V or less
(5)Voltage between joint connector (CAN1) terminal No. 2 (CAN_H) and body earth. <RHD>
OK: 4.0 V or less
(6)Voltage between joint connector (CAN1) terminal No. 13 (CAN_L) and body earth. <RHD>
OK: 4.0 V or less
(7)Disconnect the negative battery terminal.

Q. Is the check result normal?
<4.0 V or less> Go to Step 17.
NO : <More than 4.0 V> Go to Step 15.

STEP 15. M.U.T.-III CAN bus diagnostics [KOS&OSS-ECU connector disconnected]. <Vehicles with KOS>
caution Strictly observe the specified wiring harness repair procedure. For details refer to service precautions.
(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 16.

STEP 16. M.U.T.-III CAN bus diagnostics (retest the system). <Vehicles with KOS>
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.

STEP 17. Check the CAN line between joint connector (CAN1) and the combination meter. Voltage measurement at joint connector (CAN1).
caution
  • A digital multimeter should be used. For details refer to service precautions.
  • The test wiring harness should be used. For details refer to service precautions.
(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?
YES <Vehicles with automatic A/C> : <4.0 V or less> Go to Step 20.
YES <Vehicles without automatic A/C> : <4.0 V or less> Go to Step 23.
<More than 4.0 V> Go to Step 18.

STEP 18. M.U.T.-III CAN bus diagnostics [combination meter connector disconnected].
caution Strictly observe the specified wiring harness repair procedure. For details refer to service precautions.
(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 19.

STEP 19. 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.

STEP 20. Check the CAN line between joint connector (CAN1) and the A/C-ECU. Voltage measurement at joint connector (CAN1). <Vehicles with automatic A/C>
caution
  • A digital multimeter should be used. For details refer to service precautions.
  • The test wiring harness should be used. For details refer to service precautions.
(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. <LHD>
OK: 4.0 V or less
(4)Voltage between joint connector (CAN1) terminal No. 18 (CAN_L) and body earth. <LHD>
OK: 4.0 V or less
(5)Voltage between joint connector (CAN1) terminal No. 1 (CAN_H) and body earth. <RHD>
OK: 4.0 V or less
(6)Voltage between joint connector (CAN1) terminal No. 12 (CAN_L) and body earth. <RHD>
OK: 4.0 V or less
(7)Disconnect the negative battery terminal.

Q. Is the check result normal?
<4.0 V or less> Go to Step 23.
<More than 4.0 V> Go to Step 21.

STEP 21. M.U.T.-III CAN bus diagnostics [A/C-ECU connector disconnected]. <Vehicles with automatic A/C>
caution Strictly observe the specified wiring harness repair procedure. For details refer to service precautions.
(1)Disconnect A/C-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 A/C-ECU connector.

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

STEP 22. M.U.T.-III CAN bus diagnostics (retest the system). <Vehicles with automatic A/C>
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/C-ECU connector, and repair if necessary. If the A/C-ECU connector is in good condition, replace the A/C-ECU.

STEP 23. 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. For details refer to service precautions.
  • The test wiring harness should be used. For details refer to service precautions.
(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. 4 (CAN_H) and body earth.
OK: 4.0 V or less
(4)Voltage between joint connector (CAN1) terminal No. 15 (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 26.
<More than 4.0 V> Go to Step 24.

STEP 24. M.U.T.-III CAN bus diagnostics [SRS-ECU connector disconnected].
caution Strictly observe the specified wiring harness repair procedure. For details refer to service precautions.
(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 25.

STEP 25. 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.

STEP 26. Check the CAN line between joint connector (CAN1) and the diagnosis connector. Voltage measurement at joint connector (CAN1).
caution
  • A digital multimeter should be used. For details refer to service precautions.
  • The test wiring harness should be used. For details refer to service precautions.
  • Strictly observe the specified wiring harness repair procedure. For details refer to service precautions.
(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: Less than 1.0 V
(4)Voltage between joint connector (CAN1) terminal No. 19 (CAN_L) and body earth.
OK: Less than 1.0 V
(5)Disconnect the negative battery terminal.

Q. Is the check result normal?
<Less than 1.0 V> Repair the intermediate connector, or the wiring harness between joint connector (CAN1) and the intermediate connector C-213.
<1.0 V or more> Repair the diagnosis connector, or the wiring harness between joint connector (CAN1) 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 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 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 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.

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