Diagnosis Item 23: Short to power supply or earth in both CAN_H and CAN_L lines of the CAN-B bus 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 JUDGEMENT 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-411 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-411 ETACS-ECU connector terminal No.6 and body earth.
OK: 5 V or less
(4)Measure the voltage between C-411 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 8.

STEP 2. Check the wiring harness between C-126 SRS connector and C-05 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-05 joint connector (CAN1) terminal No.10 and body earth.
OK: 1 kΩ or more
(3)Measure the resistance between C-05 joint connector (CAN1) terminal No.21 and body earth.
OK: 1 kΩ or more

Q. Is the check result normal?
Go to Step 3.
Go to Step 14.

STEP 3. Check the wiring harness between C-237 heater control panel <vehicles without A/C> or C-216 A/C control panel <vehicles with A/C> connector and C-05 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-05 joint connector (CAN1) terminal No.6 and body earth.
OK: 1 kΩ or more
(3)Measure the resistance between C-05 joint connector (CAN1) terminal No.17 and body earth.
OK: 1 kΩ or more

Q. Is the check result normal?
Go to Step 4.
Go to Step 15.

STEP 4. Check the wiring harness between C-203 combination meter connector and C-05 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-05 joint connector (CAN1) terminal No.7 and body earth.
OK: 1 kΩ or more
(3)Measure the resistance between C-05 joint connector (CAN1) terminal No.18 and body earth.
OK: 1 kΩ or more

Q. Is the check result normal?
Go to Step 5.
Go to Step 16.

STEP 5. Check the wiring harness between C-09 WCM connector <vehicles without KOS> or C-10 KOS-ECU connector <vehicles with KOS> and C-05 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-05 joint connector (CAN1) terminal No.9 and body earth.
OK: 1 kΩ or more
(3)Measure the resistance between C-05 joint connector (CAN1) terminal No.20 and body earth.
OK: 1 kΩ or more

Q. Is the check result normal?
YES <vehicles with KOS> : Go to Step 6.
YES <vehicles without KOS> : Go to Step 7.
NO <the check result is not normal. (vehicles without KOS)> : Go to Step 17.
NO <the check result is not normal. (vehicles with KOS)> : Go to Step 18.

STEP 6. Check the wiring harness between C-14 OSS-ECU connector and C-05 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-05 joint connector (CAN1) terminal No.5 and body earth.
OK: 1 kΩ or more
(3)Measure the resistance between C-05 joint connector (CAN1) terminal No.16 and body earth.
OK: 1 kΩ or more

Q. Is the check result normal?
Go to Step 7.
Go to Step 19.

STEP 7. Check the wiring harness between C-411 ETACS-ECU connector and C-05 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-05 joint connector (CAN1) terminal No.11 and body earth.
OK: 1 kΩ or more
(3)Measure the resistance between C-05 joint connector (CAN1) terminal No.22 and body earth.
OK: 1 kΩ or more

Q. Is the check result normal?
Go to Step 20.
Repair the wiring harness between C-411 ETACS-ECU connector and C-05 joint connector (CAN1).

STEP 8. Check the wiring harness between C-126 SRS connector and C-05 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-05 joint connector (CAN1) terminal No.10 and body earth. <CAN_H>
OK: 5 V or less
(4)Measure the voltage between C-05 joint connector (CAN1) terminal No.21 and body earth. <CAN_L>
OK: 5 V or less

Q. Is the check result normal?
Go to Step 9.
Go to Step 14.

STEP 9. Check the wiring harness between C-237 heater control panel <vehicles without A/C> or C-216 A/C control panel <vehicles with A/C> connector and C-05 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-05 joint connector (CAN1) terminal No.6 and body earth.
OK: 5 V or less
(4)Measure the voltage between C-05 joint connector (CAN1) terminal No.17 and body earth.
OK: 5 V or less

Q. Is the check result normal?
Go to Step 10.
Go to Step 15.

STEP 10. Check the wiring harness between C-203 combination meter connector and C-05 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-05 joint connector (CAN1) terminal No.7 and body earth.
OK: 5 V or less
(4)Measure the voltage between C-05 joint connector (CAN1) terminal No.18 and body earth.
OK: 5 V or less

Q. Is the check result normal?
Go to Step 11.
Go to Step 16.

STEP 11. Check the wiring harness between C-09 WCM connector <vehicles without KOS> or C-10 KOS-ECU connector <vehicles with KOS> and C-05 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-05 joint connector (CAN1) terminal No.9 and body earth.
OK: 5 V or less
(4)Measure the voltage between C-05 joint connector (CAN1) terminal No.20 and body earth.
OK: 5 V or less

Q. Is the check result normal?
YES <vehicles with KOS> : Go to Step 12.
YES <vehicles without KOS> : Go to Step 13.
NO <the check result is not normal. (vehicles without KOS)> : Go to Step 17.
NO <the check result is not normal. (vehicles with KOS)> : Go to Step 18.

STEP 12. Check the wiring harness between C-14 OSS-ECU connector and C-05 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-05 joint connector (CAN1) terminal No.5 and body earth.
OK: 5 V or less
(4)Measure the voltage between C-05 joint connector (CAN1) terminal No.16 and body earth.
OK: 5 V or less

Q. Is the check result normal?
Go to Step 13.
Go to Step 19.

STEP 13. Check the wiring harness between C-411 ETACS-ECU connector and C-05 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 ETACS-ECU connector and 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-05 joint connector (CAN1) terminal No.11 and body earth.
OK: 1 V or less
(4)Measure the voltage between C-105 joint connector (CAN1) terminal No.22 and body earth.
OK: 1 V or less

Q. Is the check result normal?
Go to Step 20.
Repair the wiring harness between C-411 ETACS-ECU connector and C-05 joint connector (CAN1).

STEP 14. 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-126 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-126 SRS-ECU connector and C-05 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 15. M.U.T.-III CAN bus diagnostics (checking the heater control panel <vehicles without A/C> or A/C control panel <vehicles with A/C> for internal failure)
caution Strictly observe the specified wiring harness repair procedure. For details refer to .
Disconnect C-237 heater control panel <vehicles without A/C> or C-216 A/C control panel <vehicles with A/C> 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-237 heater control panel <vehicles without A/C> or C-216 A/C control panel <vehicles with A/C> connector and C-05 joint connector (CAN1).

Check the heater control panel <vehicles without A/C> or A/C control panel <vehicles with A/C> connector, and repair if necessary. If the heater control panel <vehicles without A/C> or A/C control panel <vehicles with A/C> connector is in good condition, replace the heater control panel <vehicles without A/C> or A/C control panel <vehicles with A/C>.

STEP 16. 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-203 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-203 combination meter connector and C-05 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 17. 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-09 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-09 WCM connector and C-05 joint connector (CAN1).

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

STEP 18. 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-10 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-10 KOS-ECU connector and C-05 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 19. M.U.T.-III CAN bus diagnostics (checking the OSS-ECU for internal failure)
caution Strictly observe the specified wiring harness repair procedure. For details refer to .
Disconnect C-14 OSS-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-14 OSS-ECU connector and C-05 joint connector (CAN1).

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

STEP 20. 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.