Diagnosis Item 22: Short to power supply or earth in both CAN_H and CAN_L lines.



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.




















FUNCTION




TROUBLE JUDGMENT CONDITIONS




TROUBLESHOOTING HINTS



  • Malfunction of the connector (ETACS-ECU connector improperly connected)
  • Malfunction of the wiring harness (CAN_H and CAN_L lines are short to power supply or earth on the CAN-B line.)
  • Malfunction of ECUs

DIAGNOSIS PROCEDURE


STEP 1. Checking short to power supply (voltage measurement)


caution
  • A digital multimeter should be used. For details refer to .
  • The test wiring harness should be used. For details refer to .
(1)Disconnect C-301 ETACS-ECU connector, and measure at the wiring harness side.
(2)Turn the ignition switch to the ON position.
(3)Measure the voltage between C-301 ETACS-ECU connector terminal No.6 and body earth.
OK: 5 V or less
(4)Measure the voltage between C-301 ETACS-ECU connector terminal No.7 and body earth.
OK: 5 V or less

Q. Is the check result normal?

Go to Step 2.
Go to Step 11.

STEP 2. Check the wiring harness between C-32 SRS connector and C-105 joint connector (CAN1) for short to earth (resistance measurement).


caution
  • Disconnect the negative battery terminal. For details refer to .
  • A digital multimeter should be used. For details refer to .
  • The test wiring harness should be used. For details refer to .
(1)Disconnect joint connector (CAN1), and measure at the wiring harness side.
(2)Measure the resistance between C-105 joint connector (CAN1) terminal No.1 <LHD> or 7 <RHD> and body earth.
OK: 1 kΩ or more
(3)Measure the resistance between C-105 joint connector (CAN1) terminal No.12 <LHD> or 20 <RHD> and body earth.
OK: 1 kΩ or more

Q. Is the check result normal?

Go to Step 3.
Go to Step 20.

STEP 3. Check the wiring harness between C-111 A/C-ECU connector and C-105 joint connector (CAN1) for short to earth (resistance measurement).


caution
  • Disconnect the negative battery terminal. For details refer to .
  • A digital multimeter should be used. For details refer to .
  • The test wiring harness should be used. For details refer to .
(1)Disconnect joint connector (CAN1), and measure at the wiring harness side.
(2)Measure the resistance between C-105 joint connector (CAN1) terminal No.9 and body earth.
OK: 1 kΩ or more
(3)Measure the resistance between C-105 joint connector (CAN1) terminal No.22 and body earth.
OK: 1 kΩ or more

Q. Is the check result normal?

Go to Step 4.
Go to Step 21.

STEP 4. Check the wiring harness between C-03 combination meter connector and C-105 joint connector (CAN1) for short to earth (resistance measurement).


caution
  • Disconnect the negative battery terminal. For details refer to .
  • A digital multimeter should be used. For details refer to .
  • The test wiring harness should be used. For details refer to .
(1)Disconnect joint connector (CAN1), and measure at the wiring harness side.
(2)Measure the resistance between C-105 joint connector (CAN1) terminal No.3 and body earth.
OK: 1 kΩ or more
(3)Measure the resistance between C-105 joint connector (CAN1) terminal No.14 and body earth.
OK: 1 kΩ or more

Q. Is the check result normal?

YES <vehicles with WCM> : Go to Step 5.
YES <vehicles with KOS> : Go to Step 6.
NO (the check result is not normal.) : Go to Step 22.

STEP 5. Check the wiring harness between C-33 WCM connector and C-105 joint connector (CAN1) for short to earth (resistance measurement).


caution
  • Disconnect the negative battery terminal. For details refer to .
  • A digital multimeter should be used. For details refer to .
  • The test wiring harness should be used. For details refer to .
(1)Disconnect joint connector (CAN1), and measure at the wiring harness side.
(2)Measure the resistance between C-105 joint connector (CAN1) terminal No.5 and body earth.
OK: 1 kΩ or more
(3)Measure the resistance between C-105 joint connector (CAN1) terminal No.16 and body earth.
OK: 1 kΩ or more

Q. Is the check result normal?

YES <vehicles without audio unit and MMCS> : Go to Step 10.
YES <vehicles with audio unit> : Go to Step 7.
YES <vehicles with MMCS> : Go to Step 8.
NO (the check result is not normal.) : Go to Step 23.

STEP 6. Check the wiring harness between C-104 KOS-ECU connector and C-105 joint connector (CAN1) for short to earth (resistance measurement).


caution
  • Disconnect the negative battery terminal. For details refer to .
  • A digital multimeter should be used. For details refer to .
  • The test wiring harness should be used. For details refer to .
(1)Disconnect joint connector (CAN1), and measure at the wiring harness side.
(2)Measure the resistance between C-105 joint connector (CAN1) terminal No.8 and body earth.
OK: 1 kΩ or more
(3)Measure the resistance between C-105 joint connector (CAN1) terminal No.21 and body earth.
OK: 1 kΩ or more

Q. Is the check result normal?

YES <vehicles without audio unit and MMCS> : Go to Step 10.
YES <vehicles with audio unit> : Go to Step 7.
YES <vehicles with MMCS> : Go to Step 8.
NO (the check result is not normal.) : Go to Step 24.

STEP 7. Check the wiring harness between C-18 audio unit connector and C-105 joint connector (CAN1) for short to earth (resistance measurement).


caution
  • Disconnect the negative battery terminal. For details refer to .
  • A digital multimeter should be used. For details refer to .
  • The test wiring harness should be used. For details refer to .
(1)Disconnect joint connector (CAN1), and measure at the wiring harness side.
(2)Measure the resistance between C-105 joint connector (CAN1) terminal No.10 <LHD> or 2 <RHD> and body earth. <CAN_H>
OK: 1 kΩ or more
(3)Measure the resistance between C-105 joint connector (CAN1) terminal No.23 <LHD> or 13 <RHD> and body earth. <CAN_L>
OK: 1 kΩ or more

Q. Is the check result normal?

YES <vehicles without hands-free system> : Go to Step 10.
YES <vehicles with hands-free system> : Go to Step 9.
NO (the check result is not normal.) : Go to Step 25.

STEP 8. Check the wiring harness between C-15 CAN box unit connector and C-105 joint connector (CAN1) for short to earth (resistance measurement).


caution
  • Disconnect the negative battery terminal. For details refer to .
  • A digital multimeter should be used. For details refer to .
  • The test wiring harness should be used. For details refer to .
(1)Disconnect joint connector (CAN1), and measure at the wiring harness side.
(2)Measure the resistance between C-105 joint connector (CAN1) terminal No.10 <LHD> or 2 <RHD> and body earth.
OK: 1 kΩ or more
(3)Measure the resistance between C-105 joint connector (CAN1) terminal No.23 <LHD> or 33 <RHD> and body earth.
OK: 1 kΩ or more

Q. Is the check result normal?

YES <vehicles without hands-free system> : Go to Step 10.
YES <vehicles with hands-free system> : Go to Step 9.
NO (the check result is not normal.) : Go to Step 26.

STEP 9. Check the wiring harness between C-122 hands free-ECU connector and C-105 joint connector (CAN1) for short to earth (resistance measurement).


caution
  • Disconnect the negative battery terminal. For details refer to .
  • A digital multimeter should be used. For details refer to .
  • The test wiring harness should be used. For details refer to .
(1)Disconnect joint connector (CAN1), and measure at the wiring harness side.
(2)Measure the resistance between C-105 joint connector (CAN1) terminal No.7 <LHD> or 11 <RHD> and body earth.
OK: 1 kΩ or more
(3)Measure the resistance between C-105 joint connector (CAN1) terminal No.20 <LHD> or 24 <RHD> and body earth.
OK: 1 kΩ or more

Q. Is the check result normal?

Go to Step 10.
Go to Step 27.

STEP 10. Check the wiring harness between C-301 ETACS-ECU connector and C-105 joint connector (CAN1) for short to earth (resistance measurement).


caution
  • Disconnect the negative battery terminal. For details refer to .
  • A digital multimeter should be used. For details refer to .
  • The test wiring harness should be used. For details refer to .
  • Strictly observe the specified wiring harness repair procedure. For details refer to .
(1)Disconnect ETACS-ECU connector and joint connector (CAN1), and measure at the wiring harness side.
(2)Measure the resistance between C-105 joint connector (CAN1) terminal No.6 and body earth.
OK: 1 kΩ or more
(3)Measure the resistance between C-105 joint connector (CAN1) terminal No.19 and body earth.
OK: 1 kΩ or more

Q. Is the check result normal?

Go to Step 28.
Repair the wiring harness between C-301 ETACS-ECU connector and C-105 joint connector (CAN1).

STEP 11. Check the wiring harness between C-32 SRS connector and C-105 joint connector (CAN1) for short to power supply (voltage measurement).


caution
  • A digital multimeter should be used. For details refer to .
  • The test wiring harness should be used. For details refer to .
(1)Disconnect joint connector (CAN1), and measure at the wiring harness side.
(2)Turn the ignition switch to the ON position.
(3)Measure the voltage between C-105 joint connector (CAN1) terminal No.1 <LHD> or 7 <RHD> and body earth. <CAN_H>
OK: 5 V or less
(4)Measure the voltage between C-105 joint connector (CAN1) terminal No.12 <LHD> or 20 <RHD> and body earth. <CAN_L>
OK: 5 V or less

Q. Is the check result normal?

Go to Step 12.
Go to Step 20.

STEP 12. Check the wiring harness between C-111 A/C-ECU connector and C-105 joint connector (CAN1) for short to power supply (voltage measurement).


caution
  • A digital multimeter should be used. For details refer to .
  • The test wiring harness should be used. For details refer to .
(1)Disconnect joint connector (CAN1), and measure at the wiring harness side.
(2)Turn the ignition switch to the ON position.
(3)Measure the voltage between C-105 joint connector (CAN1) terminal No.9 and body earth.
OK: 5 V or less
(4)Measure the voltage between C-105 joint connector (CAN1) terminal No.22 and body earth.
OK: 5 V or less

Q. Is the check result normal?

Go to Step 13.
Go to Step 21.

STEP 13. Check the wiring harness between C-03 combination meter connector and C-105 joint connector (CAN1) for short to power supply (voltage measurement).


caution
  • A digital multimeter should be used. For details refer to .
  • The test wiring harness should be used. For details refer to .
(1)Disconnect joint connector (CAN1), and measure at the wiring harness side.
(2)Turn the ignition switch to the ON position.
(3)Measure the voltage between C-105 joint connector (CAN1) terminal No.3 and body earth.
OK: 5 V or less
(4)Measure the voltage between C-105 joint connector (CAN1) terminal No.14 and body earth.
OK: 5 V or less

Q. Is the check result normal?

YES <vehicles with WCM> : Go to Step 14.
YES <vehicles with KOS> : Go to Step 15.
NO (the check result is not normal.) : Go to Step 22.

STEP 14. Check the wiring harness between C-33 WCM connector and C-105 joint connector (CAN1) for short to power supply (voltage measurement).


caution
  • A digital multimeter should be used. For details refer to .
  • The test wiring harness should be used. For details refer to .
(1)Disconnect joint connector (CAN1), and measure at the wiring harness side.
(2)Turn the ignition switch to the ON position.
(3)Measure the voltage between C-105 joint connector (CAN1) terminal No.5 and body earth.
OK: 5 V or less
(4)Measure the voltage between C-105 joint connector (CAN1) terminal No.16 and body earth.
OK: 5 V or less

Q. Is the check result normal?

YES <vehicles without audio unit and MMCS> : Go to Step 19.
YES <vehicles with audio unit> : Go to Step 16.
YES <vehicles with MMCS> : Go to Step 17.
NO (the check result is not normal.) : Go to Step 23.

STEP 15. Check the wiring harness between C-104 KOS-ECU connector and C-105 joint connector (CAN1) for short to power supply (voltage measurement).


caution
  • A digital multimeter should be used. For details refer to .
  • The test wiring harness should be used. For details refer to .
(1)Disconnect joint connector (CAN1), and measure at the wiring harness side.
(2)Turn the ignition switch to the ON position.
(3)Measure the voltage between C-105 joint connector (CAN1) terminal No.8 and body earth.
OK: 5 V or less
(4)Measure the voltage between C-105 joint connector (CAN1) terminal No.21 and body earth.
OK: 5 V or less

Q. Is the check result normal?

YES <vehicles without audio unit and MMCS> : Go to Step 19.
YES <vehicles with audio unit> : Go to Step 16.
YES <vehicles with MMCS> : Go to Step 17.
NO (the check result is not normal.) : Go to Step 24.

STEP 16. Check the wiring harness between C-18 audio unit connector and C-105 joint connector (CAN1) for short to power supply (voltage measurement).


caution
  • A digital multimeter should be used. For details refer to .
  • The test wiring harness should be used. For details refer to .
(1)Disconnect joint connector (CAN1), and measure at the wiring harness side.
(2)Turn the ignition switch to the ON position.
(3)Measure the voltage between C-105 joint connector (CAN1) terminal No.10 <LHD> or 2 <RHD> and body earth.
OK: 5 V or less
(4)Measure the voltage between C-105 joint connector (CAN1) terminal No.23 <LHD> or 13 <RHD> and body earth.
OK: 5 V or less

Q. Is the check result normal?

YES <vehicles without hands-free system> : Go to Step 19.
YES <vehicles with hands-free system> : Go to Step 18.
NO (the check is not result normal.) : Go to Step 25.

STEP 17. Check the wiring harness between C-15 CAN box unit connector and C-105 joint connector (CAN1) for short to power supply (voltage measurement).


caution
  • A digital multimeter should be used. For details refer to .
  • The test wiring harness should be used. For details refer to .
(1)Disconnect joint connector (CAN1), and measure at the wiring harness side.
(2)Turn the ignition switch to the ON position.
(3)Measure the voltage between C-105 joint connector (CAN1) terminal No.10 <LHD> or 2 <RHD> and body earth.
OK: 5 V or less
(4)Measure the voltage between C-105 joint connector (CAN1) terminal No.23 <LHD> or 33 <RHD> and body earth.
OK: 5 V or less

Q. Is the check result normal?

YES <vehicles without hands-free system> : Go to Step 19.
YES <vehicles with hands-free system> : Go to Step 18.
NO (the check result is not normal.) : Go to Step 26.

STEP 18. Check the wiring harness between C-122 hands free-ECU connector and C-105 joint connector (CAN1) for short to power supply (voltage measurement).


caution
  • A digital multimeter should be used. For details refer to .
  • The test wiring harness should be used. For details refer to .
(1)Disconnect joint connector (CAN1), and measure at the wiring harness side.
(2)Turn the ignition switch to the ON position.
(3)Measure the voltage between C-105 joint connector (CAN1) terminal No.7 <LHD> or 11 <RHD> and body earth.
OK: 5 V or less
(4)Measure the voltage between C-105 joint connector (CAN1) terminal No.20 <LHD> or 24 <RHD> and body earth.
OK: 5 V or less

Q. Is the check result normal?

Go to Step 19.
Go to Step 27.

STEP 19. Check the wiring harness between C-301 ETACS-ECU connector and C-105 joint connector (CAN1) for short to power supply (voltage measurement).


caution
  • A digital multimeter should be used. For details refer to .
  • The test wiring harness should be used. For details refer to .
  • Strictly observe the specified wiring harness repair procedure. For details refer to .
(1)Disconnect joint connector (CAN1), and measure at the wiring harness side.
(2)Turn the ignition switch to the ON position.
(3)Measure the voltage between C-105 joint connector (CAN1) terminal No.6 and body earth.
OK: 5 V or less
(4)Measure the voltage between C-105 joint connector (CAN1) terminal No.19 and body earth.
OK: 5 V or less

Q. Is the check result normal?

Go to Step 28.
Repair the wiring harness between C-301 ETACS-ECU connector and C-105 joint connector (CAN1).

STEP 20. M.U.T.-III CAN bus diagnostics (checking the SRS-ECU for internal failure)


caution Strictly observe the specified wiring harness repair procedure. For details refer to .
Disconnect C-32 SRS-ECU connector, and diagnose the CAN bus line.

OK: The display of the M.U.T.-III is as shown in the figure.

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

Repair the wiring harness between C-32 SRS-ECU connector and C-105 joint connector (CAN1).

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

STEP 21. M.U.T.-III CAN bus diagnostics (checking the A/C-ECU for internal failure)


caution Strictly observe the specified wiring harness repair procedure. For details refer to .
Disconnect C-111 A/C-ECU connector, and diagnose the CAN bus line.

OK: The display of the M.U.T.-III is as shown in the figure.

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

Repair the wiring harness between C-111 A/C-ECU connector and C-105 joint connector (CAN1).

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 22. M.U.T.-III CAN bus diagnostics (checking the combination meter for internal failure)


caution Strictly observe the specified wiring harness repair procedure. For details refer to .
Disconnect C-03 combination meter connector, and diagnose the CAN bus line.

OK: The display of the M.U.T.-III is as shown in the figure.

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

Repair the wiring harness between C-03 combination meter connector and C-105 joint connector (CAN1).

Check the combination meter connector, and repair if necessary. If the combination meter connector is in good condition, replace the combination meter.

STEP 23. M.U.T.-III CAN bus diagnostics (checking the WCM for internal failure)


caution Strictly observe the specified wiring harness repair procedure. For details refer to .
Disconnect C-33 WCM connector, and diagnose the CAN bus line.

OK: The display of the M.U.T.-III is as shown in the figure.

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

Repair the wiring harness between C-33 WCM connector and C-105 joint connector (CAN1).

Check the WCM connector, and repair if necessary. If the WCM connector is in good condition, replace the WCM.

STEP 24. M.U.T.-III CAN bus diagnostics (checking the KOS-ECU for internal failure)


caution Strictly observe the specified wiring harness repair procedure. For details refer to .
Disconnect C-104 KOS-ECU connector, and diagnose the CAN bus line.

OK: The display of the M.U.T.-III is as shown in the figure.

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

Repair the wiring harness between C-104 KOS-ECU connector and C-105 joint connector (CAN1).

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

STEP 25. M.U.T.-III CAN bus diagnostics (checking the audio unit for internal failure)


caution Strictly observe the specified wiring harness repair procedure. For details refer to .
Disconnect C-18 audio unit connector, and diagnose the CAN bus line.

OK: The display of the M.U.T.-III is as shown in the figure.

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

Repair the wiring harness between C-18 audio unit connector and C-105 joint connector (CAN1).

Check the audio unit connector, and repair if necessary. If the audio unit connector is in good condition, replace the audio unit.

STEP 26. M.U.T.-III CAN bus diagnostics (checking the CAN box unit for internal failure)


caution Strictly observe the specified wiring harness repair procedure. For details refer to .
Disconnect C-15 CAN box unit connector, and diagnose the CAN bus line.

OK: The display of the M.U.T.-III is as shown in the figure.

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

Repair the wiring harness between C-15 CAB box unit connector and C-105 joint connector (CAN1).

Check the CAN box unit connector, and repair if necessary. If the CAN box unit connector is in good condition, replace the CAN box unit.

STEP 27. M.U.T.-III CAN bus diagnostics (checking the hands free ECU unit for internal failure)


caution Strictly observe the specified wiring harness repair procedure. For details refer to .
Disconnect C-122 hands free-ECU connector, and diagnose the CAN bus line.

OK: The display of the M.U.T.-III is as shown in the figure.

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

Repair the wiring harness between C-122 hands free-ECU connector and C-105 joint connector (CAN1).

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

STEP 28. Trouble symptom check


Diagnose the CAN bus line, and check that normal condition is displayed.

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.