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Home >> Mitsubishi >> 2011 >> 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 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 [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 9 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 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 7 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 8 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 11 and body ground.
OK: 1 kohms or more





(3)Measure the resistance between joint connector (CAN1) terminal 24 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 1 and body ground.
OK: 1 kohms or more





(3)Measure the resistance between joint connector (CAN1) terminal 12 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 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 [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 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 (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 2 and body ground.
OK: 1 kohms or more





(3)Measure the resistance between joint connector (CAN1) terminal 13 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 6 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 Go to Step 31.

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