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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 24 >> Part 1

Part 1




DIAGNOSTIC ITEM 24: Short to power supply or ground in both CAN_H and CAN_L lines of 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 is present in both CAN_H and CAN_L lines, this diagnosis result will be set.

TROUBLE JUDGMENT CONDITIONS

If a communication flag is set for the ETACS-ECU, no communication is present through the CAN-B line, and diagnostic trouble code U0019 is set, the ETACS-ECU determines that there is a failure.

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 ground on the CAN-B line.)
- Malfunction of ECUs

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 power supply. Measure the voltage at ETACS-ECU connector C-301.

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)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 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 22.

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 23.

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 24.

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 25.

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 26.

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 27.

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 28.

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 29.

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 30.

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 31.

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

STEP 12. 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.

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 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 7 and body ground.
OK: 4.7 V or less





(4)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 13.

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

NO (vehicles with KOS and WCM) : Go to Step 22.

STEP 13. 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.

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 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 15.

NO Go to Step 23.

STEP 14. 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.

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 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 15.

NO Go to Step 24.

STEP 15. 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.

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 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 16.

NO Go to Step 25.

STEP 16. 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.

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 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 17.

NO : Go to Step 26.

STEP 17. 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.

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 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 18.

YES (vehicles with MMCS) : Go to Step 19.

NO : Go to Step 27.

STEP 18. 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.

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 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 21.

YES (vehicles with satellite radio) : Go to Step 20.

NO : Go to Step 28.

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