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Home >> Mitsubishi >> 2012 >> Lancer Evolution L4-2.0L Turbo (4B11T/C) >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> Information Bus >> Testing and Inspection >> Component Tests and General Diagnostics >> Diagnostics Item 26 >> Part 1

Part 1




DIAGNOSTIC ITEM 26: Short to power supply or ground, open circuit or line-to-line short in the CAN-B bus lines.

CAUTION:
When servicing a CAN bus line, ground yourself by touching a metal object such as an unpainted water pipe. If you fail to do so, a component connected to the CAN bus line may be damaged.


























FUNCTION

If a short to power supply or ground, open circuit or line-to-line short is present at either CAN_H or CAN_L side on the CAN-B lines, this diagnosis result will be set.

TROUBLE JUDGMENT CONDITIONS

When CAN-B lines communication is normal, and diagnostic trouble code U0019 is set, the ETACS-ECU determines that there is a failure.

TROUBLESHOOTING HINTS

- Malfunction of the connector (short to power supply or ground in connector or improperly connected)
- Malfunction of the wiring harness (short to power supply or ground, open circuit or line-to-line short in CAN bus lines)
- Faulty ECU(s) (internal short to power supply or ground)

DIAGNOSIS

Required Special Tools:

- MB991223: Harness Set
- MB992006: Extra Fine Probe

STEP 1. Check the wiring harness between ETACS-ECU connector C-301 and body ground for a short to ground. Measure the resistance at ETACS-ECU connector C-301.

CAUTION:
Disconnect the negative battery terminal. For details refer to Precautions When CAN Bus Line(s) are Repaired.

CAUTION:
A digital multimeter should be used. For details refer to Precautions When CAN Bus Line(s) are Repaired.

CAUTION:
The test wiring harness should be used. For details refer to Precautions When CAN Bus Line(s) are Repaired.

(1)Disconnect ETACS-ECU connector C-301, and measure the voltage at the wiring harness side of ETACS-ECU connector.





(2)Measure the resistance between ETACS-ECU connector terminal 6 and body ground.
OK: 1 kohms or more





(3)Measure the resistance between ETACS-ECU connector terminal 7 and body ground.
OK: 1 kohms or more
Q. Do all the resistances measure 1 kohms or more?

YES Go to Step 2.

NO Go to Step 12.

STEP 2. Check the wiring harness between joint connector (CAN1) C-105 and combination meter connector C-04 for a short to ground. Measure the resistance at joint connector (CAN1) C-105.

(1)Disconnect joint connector (CAN1), and measure the resistance at the wiring harness side of joint connector (CAN1).





(2)Measure the resistance between joint connector (CAN1) terminal 7 and body ground.
OK: 1 kohms or more





(3)Measure the resistance between joint connector (CAN1) terminal 18 and body ground.
OK: 1 kohms or more
Q. Do all the resistances measure 1 kohms or more?

YES (vehicles with KOS) : Go to Step 3.

YES (vehicles with WCM) : Go to Step 4.

NO (vehicles with KOS or WCM) : Go to Step 44.

STEP 3. Check the wiring harness between joint connector (CAN1) C-105 and KOS-ECU connector C-05 for a short to ground. Measure the resistance at joint connector
(CAN1) C-105.

(1)Disconnect joint connector (CAN1), and measure the resistance at the wiring harness side of joint connector (CAN1).





(2)Measure the resistance between joint connector (CAN1) terminal 5 and body ground.
OK: 1 kohms or more





(3)Measure the resistance between joint connector (CAN1) terminal 16 and body ground.
OK: 1 kohms or more
Q. Do all the resistances measure 1 kohms or more?

YES Go to Step 5.

NO Go to Step 45.

STEP 4. Check the wiring harness between joint connector (CAN1) C-105 and WCM connector C-07 for a short to ground. Measure the resistance at joint connector (CAN1) C-105.

(1)Disconnect joint connector (CAN1), and measure the resistance at the wiring harness side of joint connector (CAN1).





(2)Measure the resistance between joint connector (CAN1) terminal 9 and body ground.
OK: 1 kohms or more





(3)Measure the resistance between joint connector (CAN1) terminal 20 and body ground.
OK: 1 kohms or more
Q. Do all the resistances measure 1 kohms or more?

YES Go to Step 5.

NO Go to Step 46.

STEP 5. Check the wiring harness between joint connector (CAN1) C-105 and SRS-ECU connector C-37 for a short to ground. Measure the resistance at joint connector
(CAN1) C-105.

(1)Disconnect joint connector (CAN1), and measure the resistance at the wiring harness side of joint connector (CAN1).





(2)Measure the resistance between joint connector (CAN1) terminal 10 and body ground.
OK: 1 kohms or more





(3)Measure the resistance between joint connector (CAN1) terminal 21 and body ground.
OK: 1 kohms or more
Q. Do all the resistances measure 1 kohms or more?

YES Go to Step 6.

NO Go to Step 47.

STEP 6. Check the wiring harness between joint connector (CAN1) C-105 and occupant classification-ECU connector D-39-2 for a short to ground. Measure the resistance at joint connector (CAN1) C-105.

(1)Disconnect joint connector (CAN1), and measure the resistance at the wiring harness side of joint connector (CAN1).





(2)Measure the resistance between joint connector (CAN1) terminal 3 and body ground.
OK: 1 kohms or more





(3)Measure the resistance between joint connector (CAN1) terminal 14 and body ground.
OK: 1 kohms or more
Q. Do all the resistances measure 1 kohms or more?

YES Go to Step 7.

NO : Go to Step 48.

STEP 7. Check the wiring harness between joint connector (CAN1) C-105 and A/C-ECU connector C-22 [vehicles with A/C] or heater control unit connector C-53 [vehicles without A/C] for a short to ground. Measure the resistance at joint connector (CAN1) C-105.

(1)Disconnect joint connector (CAN1), and measure the resistance at the wiring harness side of joint connector (CAN1).





(2)Measure the resistance between joint connector (CAN1) terminal 6 and body ground.
OK: 1 kohms or more





(3)Measure the resistance between joint connector (CAN1) terminal 17 and body ground.
OK: 1 kohms or more
Q. Do all the resistances measure 1 kohms or more?

YES (vehicles without MMCS) : Go to Step 8.

YES (vehicles with MMCS) : Go to Step 9.

NO : Go to Step 49.

STEP 8. Check the wiring harness between joint connector (CAN1) C-105 and radio and CD player or CD changer connector C-107 for a short to ground. Measure the resistance at joint connector (CAN1) C-105.

(1)Disconnect joint connector (CAN1), and measure the resistance at the wiring harness side of joint connector (CAN1).





(2)Measure the resistance between joint connector (CAN1) terminal 8 and body ground.
OK: 1 kohms or more





(3)Measure the resistance between joint connector (CAN1) terminal 19 and body ground.
OK: 1 kohms or more
Q. Do all the resistances measure 1 kohms or more?

YES (vehicles without satellite radio) : Go to Step 11.

YES (vehicles with satellite radio) : Go to Step 10.

NO : Go to Step 50.

STEP 9. Check the wiring harness between joint connector (CAN1) C-105 and CAN box unit connector C-15 for a short to ground. Measure the resistance at joint connector (CAN1) C-105.

(1)Disconnect joint connector (CAN1), and measure the resistance at the wiring harness side of joint connector (CAN1).





(2)Measure the resistance between joint connector (CAN1) terminal 8 and body ground.
OK: 1 kohms or more





(3)Measure the resistance between joint connector (CAN1) terminal 19 and body ground.
OK: 1 kohms or more
Q. Do all the resistances measure 1 kohms or more?

YES (vehicles without satellite radio) : Go to Step 11.

YES (vehicles with satellite radio) : Go to Step 10.

NO : Go to Step 51.

STEP 10. Check the wiring harness between joint connector (CAN1) C-105 and satellite radio tuner connector C-18 for a short to ground. Measure the resistance at joint connector (CAN1) C-105.

(1)Disconnect joint connector (CAN1), and measure the resistance at the wiring harness side of joint connector (CAN1).





(2)Measure the resistance between joint connector (CAN1) terminal 4 and body ground.
OK: 1 kohms or more





(3)Measure the resistance between joint connector (CAN1) terminal 15 and body ground.
OK: 1 kohms or more
Q. Do all the resistances measure 1 kohms or more?

YES Go to Step 11.

NO Go to Step 52.

STEP 11. Check the wiring harness between joint connector (CAN1) C-105 and ETACS-ECU connector C-301 for a short to ground. Measure the resistance at joint connector
(CAN1) C-105.

(1)Disconnect joint connector (CAN1) and ETACS-ECU connector C-301, and measure the resistance at the wiring harness side of joint connector (CAN1).





(2)Measure the resistance between joint connector (CAN1) terminal 11 and body ground.
OK: 1 kohms or more





(3)Measure the resistance between joint connector (CAN1) terminal 22 and body ground.
OK: 1 kohms or more
Q. Do all the resistances measure 1 kohms or more?

YES Go to Step 53.

NO Repair the wiring harness between joint connector (CAN1) C-105 and ETACS-ECU connector C-301.

STEP 12. Check the wiring harness between ETACS-ECU connector C-301 and body ground for a short to power supply. Measure the voltage at ETACS-ECU connector C-301.

(1)Disconnect ETACS-ECU connector C-301, and measure the voltage at the wiring harness side of ETACS-ECU connector.

(2)Turn the ignition switch to the ON position.





(3)Measure the voltage between ETACS-ECU connector terminal 6 and body ground.
OK: 4.7 V or less





(4)Measure the voltage between ETACS-ECU connector terminal 7 and body ground.
OK: 4.7 V or less
Q. Do all the voltages measure 4.7 V or less?

YES Go to Step 23.

NO Go to Step 13.

STEP 13. Check the wiring harness between joint connector (CAN1) C-105 and combination meter connector C-04 for a short to power supply. Measure the voltage at joint connector (CAN1) C-105.

(1)Disconnect joint connector (CAN1), and measure the voltage at the wiring harness side of joint connector (CAN1).

(2)Connect the negative battery terminal.

(3)Turn the ignition switch to the ON position.





(4)Measure the voltage between joint connector (CAN1) terminal 7 and body ground.
OK: 4.7 V or less





(5)Measure the voltage between joint connector (CAN1) terminal 18 and body ground.
OK: 4.7 V or less
Q. Do all the voltages measure 4.7 V or less?

YES (vehicles with KOS) : Go to Step 14.

YES (vehicles with WCM) : Go to Step 15.

NO (vehicles with KOS and WCM) : Go to Step 44.

STEP 14. Check the wiring harness between joint connector (CAN1) C-105 and KOS-ECU connector C-05 for a short to power supply. Measure the voltage at joint connector
(CAN1) C-105.

(1)Disconnect joint connector (CAN1), and measure the voltage at the wiring harness side of joint connector (CAN1).

(2)Turn the ignition switch to the ON position.





(3)Measure the voltage between joint connector (CAN1) terminal 5 and body ground.
OK: 4.7 V or less





(4)Measure the voltage between joint connector (CAN1) terminal 16 and body ground.
OK: 4.7 V or less
Q. Do all the voltages measure 4.7 V or less?

YES Go to Step 16.

NO Go to Step 45.

STEP 15. Check the wiring harness between joint connector (CAN1) C-105 and WCM connector C-07 for a short to power supply. Measure the voltage at joint connector (CAN1) C-105.

(1)Disconnect joint connector (CAN1), and measure the voltage at the wiring harness side of joint connector (CAN1).

(2)Turn the ignition switch to the ON position.





(3)Measure the voltage between joint connector (CAN1) terminal 9 and body ground.
OK: 4.7 V or less





(4)Measure the voltage between joint connector (CAN1) terminal 20 and body ground.
OK: 4.7 V or less
Q. Do all the voltages measure 4.7 V or less?

YES Go to Step 16.

NO Go to Step 46.

STEP 16. Check the wiring harness between joint connector (CAN1) C-105 and SRS-ECU connector C-37 for a short to power supply. Measure the voltage at joint connector
(CAN1) C-105.

(1)Disconnect joint connector (CAN1), and measure the voltage at the wiring harness side of joint connector (CAN1).

(2)Turn the ignition switch to the ON position.





(3)Measure the voltage between joint connector (CAN1) terminal 10 and body ground.
OK: 4.7 V or less





(4)Measure the voltage between joint connector (CAN1) terminal 21 and body ground.
OK: 4.7 V or less
Q. Do all the voltages measure 4.7 V or less?

YES Go to Step 17.

NO Go to Step 47.

STEP 17. Check the wiring harness between joint connector (CAN1) C-105 and occupant classification-ECU connector D-39-2 for a short to power supply. Measure the voltage at joint connector (CAN1) C-105.

(1)Disconnect joint connector (CAN1), and measure the voltage at the wiring harness side of joint connector (CAN1).

(2)Turn the ignition switch to the ON position.





(3)Measure the voltage between joint connector (CAN1) terminal 3 and body ground.
OK: 4.7 V or less





(4)Measure the voltage between joint connector (CAN1) terminal 14 and body ground.
OK: 4.7 V or less
Q. Do all the voltages measure 4.7 V or less?

YES Go to Step 18.

NO : Go to Step 48.

STEP 18. Check the wiring harness between joint connector (CAN1) C-105 and A/C-ECU connector C-22 [vehicles with A/C] or heater control unit connector C-53 [vehicles without A/C] for a short to power supply. Measure the voltage at joint connector (CAN1) C-105.

(1)Disconnect joint connector (CAN1), and measure the voltage at the wiring harness side of joint connector (CAN1).

(2)Turn the ignition switch to the ON position.





(3)Measure the voltage between joint connector (CAN1) terminal 6 and body ground.
OK: 4.7 V or less





(4)Measure the voltage between joint connector (CAN1) terminal 17 and body ground.
OK: 4.7 V or less
Q. Do all the voltages measure 4.7 V or less?

YES (vehicles without MMCS) : Go to Step 19.

YES (vehicles with MMCS) : Go to Step 20.

NO : Go to Step 49.

STEP 19. Check the wiring harness between joint connector (CAN1) C-105 and radio and CD player or CD changer connector C-107 for a short to power supply. Measure the voltage at joint connector (CAN1) C-105.

(1)Disconnect joint connector (CAN1), and measure the voltage at the wiring harness side of joint connector (CAN1).

(2)Turn the ignition switch to the ON position.





(3)Measure the voltage between joint connector (CAN1) terminal 8 and body ground.
OK: 4.7 V or less





(4)Measure the voltage between joint connector (CAN1) terminal 19 and body ground.
OK: 4.7 V or less
Q. Do all the voltages measure 4.7 V or less?

YES (vehicles without satellite radio) : Go to Step 22.

YES (vehicles with satellite radio) : Go to Step 21.

NO : Go to Step 50.

STEP 20. Check the wiring harness between joint connector (CAN1) C-105 and CAN box unit connector C-15 for a short to power supply. Measure the voltage at joint connector
(CAN1) C-105.

(1)Disconnect joint connector (CAN1), and measure the voltage at the wiring harness side of joint connector (CAN1).

(2)Turn the ignition switch to the ON position.





(3)Measure the voltage between joint connector (CAN1) terminal 8 and body ground.
OK: 4.7 V or less





(4)Measure the voltage between joint connector (CAN1) terminal 19 and body ground.
OK: 4.7 V or less
Q. Do all the voltages measure 4.7 V or less?

YES (vehicles without satellite radio) : Go to Step 22.

YES (vehicles with satellite radio) : Go to Step 21.

NO : Go to Step 51.

STEP 21. Check the wiring harness between joint connector (CAN1) C-105 and satellite radio tuner connector C-18 for a short to power supply. Measure the voltage at joint connector (CAN1) C-105.

(1)Disconnect joint connector (CAN1), and measure the voltage at the wiring harness side of joint connector (CAN1).

(2)Turn the ignition switch to the ON position.





(3)Measure the voltage between joint connector (CAN1) terminal 4 and body ground.
OK: 4.7 V or less





(4)Measure the voltage between joint connector (CAN1) terminal 15 and body ground.
OK: 4.7 V or less
Q. Do all the voltages measure 4.7 V or less?

YES Go to Step 22.

NO Go to Step 52.

STEP 22. Check the wiring harness between joint connector (CAN1) C-105 and ETACS-ECU connector C-301 for a short to power supply. Measure the voltage at joint connector
(CAN1) C-105.

(1)Disconnect joint connector (CAN1) and ETACS-ECU connector C-301, and measure the voltage at the wiring harness side of joint connector (CAN1).

(2)Turn the ignition switch to the ON position.





(3)Measure the voltage between joint connector (CAN1) terminal 11 and body ground.
OK: 1 V or less





(4)Measure the voltage between joint connector (CAN1) terminal 22 and body ground.
OK: 1 V or less
Q. Do all the voltages measure 1 V or less?

YES Go to Step 53.

NO Repair the wiring harness between joint connector (CAN1) C-105 and ETACS-ECU connector C-301.

STEP 23. Check the wiring harness for line-to-line short. Measure the resistance at ETACS-ECU connector C-301

CAUTION:
Disconnect the negative battery terminal. For details refer to Precautions When CAN Bus Line(s) are Repaired.

(1)Disconnect ETACS-ECU connector C-301, and check that there is continuity at the harness side of ETACS-ECU.





(2)Check that there is continuity between ETACS-ECU connector terminals 6 and 7.
OK: No continuity
Q. Is the check result normal?

YES Go to Step 34.

NO Go to Step 24.

STEP 24. Check the wiring harness between joint connector (CAN1) C-105 and combination meter connector C-04 for line-to-line short. Measure the resistance at joint connector
(CAN1) C-105.

(1)Disconnect joint connector (CAN1), and check that there is continuity at the harness side of joint connector (CAN1).





(2)Check that there is continuity between joint connector (CAN1) terminals 7 and 18.
OK: No continuity
Q. Is the check result normal?

YES (vehicles with KOS) : Go to Step 25.

YES (vehicles with WCM) : Go to Step 26.

NO (vehicles with KOS or WCM) : Go to Step 44.

STEP 25. Check the wiring harness between joint connector (CAN1) C-105 and KOS-ECU connector C-05 for line-to-line short. Measure the resistance at joint connector
(CAN1) C-105.

(1)Disconnect joint connector (CAN1), and check that there is continuity at the harness side of joint connector (CAN1).





(2)Check that there is continuity between joint connector (CAN1) terminals 5 and 16.
OK: No continuity
Q. Is the check result normal?

YES Go to Step 27.

NO Go to Step 45.

STEP 26. Check the wiring harness between joint connector (CAN1) C-105 and WCM connector C-07 for line-to-line short. Measure the resistance at joint connector (CAN1) C-105.

(1)Disconnect joint connector (CAN1), and check that there is continuity at the harness side of joint connector (CAN1).





(2)Check that there is continuity between joint connector (CAN1) terminals 9 and 20.
OK: No continuity
Q. Is the check result normal?

YES Go to Step 27.

NO Go to Step 46.

STEP 27. Check the wiring harness between joint connector (CAN1) C-105 and SRS-ECU connector C-37 for line-to-line short. Measure the resistance at joint connector
(CAN1) C-105.

(1)Disconnect joint connector (CAN1), and check that there is continuity at the harness side of joint connector (CAN1).





(2)Check that there is continuity between joint connector (CAN1) terminals 10 and 21.
OK: No continuity
Q. Is the check result normal?

YES Go to Step 28.

NO Go to Step 47.

STEP 28. Check the wiring harness between joint connector (CAN1) C-105 and occupant classification-ECU connector D-39-2 for line-to-line short. Measure the resistance at joint connector (CAN1) C-105.

(1)Disconnect joint connector (CAN1), and check that there is continuity at the harness side of joint connector (CAN1).





(2)Check that there is continuity between joint connector (CAN1) terminals 3 and 14.
OK: No continuity
Q. Is the check result normal?

YES Go to Step 29.

NO : Go to Step 48.

STEP 29. Check the wiring harness between joint connector (CAN1) C-105 and A/C-ECU connector C-22 [vehicles with A/C] or heater control unit connector C-53 [vehicles without A/C] for line-to-line short. Measure the resistance at joint connector (CAN1) C-105.

(1)Disconnect joint connector (CAN1), and check that there is continuity at the harness side of joint connector (CAN1).





(2)Check that there is continuity between joint connector (CAN1) terminals 6 and 17.
OK: No continuity
Q. Is the check result normal?

YES (vehicles without MMCS) : Go to Step 30.

YES (vehicles with MMCS) : Go to Step 31.

NO : Go to Step 49.

STEP 30. Check the wiring harness between joint connector (CAN1) C-105 and radio and CD player or CD changer connector C-107 for line-to-line short. Measure the resistance at joint connector (CAN1) C-105.

(1)Disconnect joint connector (CAN1), and check that there is continuity at the harness side of joint connector (CAN1).





(2)Check that there is continuity between joint connector (CAN1) terminals 8 and 19.
OK: No continuity
Q. Is the check result normal?

YES (vehicles without satellite radio) : Go to Step 33.

YES (vehicles with satellite radio) : Go to Step 32.

NO : Go to Step 50.

STEP 31. Check the wiring harness between joint connector (CAN1) C-105 and CAN box unit connector C-15 for line-to-line short. Measure the resistance at joint connector
(CAN1) C-105.

(1)Disconnect joint connector (CAN1), and check that there is continuity at the harness side of joint connector (CAN1).





(2)Check that there is continuity between joint connector (CAN1) terminals 8 and 19.
OK: No continuity
Q. Is the check result normal?

YES (vehicles without satellite radio) : Go to Step 33.

YES (vehicles with satellite radio) : Go to Step 32.

NO : Go to Step 51.

STEP 32. Check the wiring harness between joint connector (CAN1) C-105 and satellite radio tuner connector C-18 for line-to-line short. Measure the resistance at joint connector (CAN1) C-105.

(1)Disconnect joint connector (CAN1), and check that there is continuity at the harness side of joint connector (CAN1).





(2)Check that there is continuity between joint connector (CAN1) terminals 4 and 15.
OK: No continuity
Q. Is the check result normal?

YES Go to Step 33.

NO Go to Step 52.

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