Operation CHARM: Car repair manuals for everyone.
Home >> Mitsubishi >> 2005 >> Outlander L4-2.4L SOHC >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> Information Bus >> Testing and Inspection >> Symptom Related Diagnostic Procedures >> Symptom Diagnostic Procedures >> A - Charts >> Inspection Procedure A-4

Inspection Procedure A-4

Communication with the front-ECU is not possible.

Front-ECU Power Supply And SWS Communication Circuit Part 1:




Front-ECU Power Supply And SWS Communication Circuit Part 2:






NOTE: This troubleshooting procedure requires the use of scan tool MB991958 and SWS monitor kit MB991813. For details on how to use the SWS monitor, refer to "How to use SWS monitor." How To Use SWS Monitor

CIRCUIT OPERATION
- The power supply to the front-ECU is provided by the battery and the ignition switch (IG2).
- If the power supply system from the battery is defective, the system operates by the power supply from the ignition switch (IG2).

TECHNICAL DESCRIPTION (COMMENT)
It is suspected that the power supply circuit to the front-ECU is defective, or the wiring harness between the SWS monitor kit and the front-ECU or their connector(s) is damaged. If the battery power supply circuit to the ECU (terminal 7 of the front-ECU) is damaged, also check the power supply circuit from the ignition switch (IG2) (terminal 30 of the front-ECU), and repair if necessary.

TROUBLESHOOTING HINTS
- The ETACS-ECU may be defective
- The front-ECU may be defective
- The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector

DIAGNOSIS

Required Special Tools:
- MB991223: Harness Set
- MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: Vehicle Communication Interface (V.C.I.)
- MB991827: MUT-III USB Cable
- MB991910: MUT-III Main Harness A
- MB991813: SWS monitor kit
- MB991806: SWS Monitor Cartridge
- MB991812: SWS Monitor Harness (For Column-ECU)
- MB991822: Probe Harness
- MB991854: SWS Monitor Harness (For 13-pin)

STEP 1. Use scan tool MB991958 to select "ECU COMM CHK" on the SWS monitor display.

Check the ETACS-ECU.

CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.




1. Connect scan tool MB991958 to the data link connector (16-pin).
2. Connect SWS monitor harness MB991854 to the data link connector (13-pin).
3. Turn the ignition switch to the "LOCK" (OFF) position.
4. Operate the scan tool MB991958 according to the procedure below to display "ECU COMM CHECK."
a. Select "SYSTEM SELECT."
b. Select "SWS."
c. Select "SWS MONITOR."
d. Select "ECU COMM CHK".

5. Scan tool MB991958 should show "OK" on the "ECU COMM CHK" menu for the "ETACS ECU" menu.

Q: Is "OK" displayed on the "ETACS ECU" menu?

YES: Go to Step 2.

NO: Refer to Inspection Procedure A-3 "Communication with the ETACS-ECU is not possible."




STEP 2. Check the front-ECU connector A-11X for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is the front-ECU connector A-11X in good condition?

YES: Go to Step 3.

NO: Repair or replace the damaged components). Refer to Harness Connector Inspection. Verify that the system should communicate with the front-ECU normally.

STEP 3. Check the battery power supply circuit to the front-ECU. Measure the voltage at front-ECU connector A-11X.




1. Disconnect front-ECU connector A-11X and measure the voltage available at the relay box side of the connector.




2. Measure the voltage between terminal 5 and ground.
- The voltage should equal approximately 12 volts (battery positive voltage).

Q: Is the measured voltage approximately 12 volts (battery positive voltage)?

YES: Go to Step 5.

NO: Go to Step 4.




STEP 4. Check the wiring harness between front-ECU connector A-11X (terminal 5) and the battery.

Q: Is the wiring harness between front-ECU connector A-11X (terminal 5) and the battery in good condition?

YES: No action is necessary and testing is complete.

NO: The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary. Verify that the system should communicate with the front-ECU normally.




STEP 5. Check the front-ECU connector A-12X for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is front-ECU connector A-12X in good condition?

YES: Go to Step 6.

NO: Repair or replace the damaged components). Refer to Harness Connector Inspection. Verify that the system should communicate with the front-ECU normally.

STEP 6. Check the ground circuit to the front-ECU. Measure the resistance at front-ECU connector A-12X.




1. Disconnect front-ECU connector A-12X and measure the resistance available at the relay box side of the connector.




2. Measure the resistance value between terminal 21 and ground.
- The resistance should equal 2 Ohms or less.

Q: Is the measured resistance 2 Ohms or less?

YES: Go to Step 8.

NO: Go to Step 7.




STEP 7. Check the wiring harness between front-ECU connector A-12X (terminal 21) and the ground.

Q: Is the wiring harness between front-ECU connector A-12X (terminal 21) and ground in good condition?

YES: No action is necessary and testing is complete.

NO: The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary. Verify that the system should communicate with the front-ECU normally.




STEP 8. Check the ETACS-ECU connector C-219 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is ETACS-ECU connector C-219 in good condition?

YES: Go to Step 9.

NO: Repair or replace the damaged components). Refer to Harness Connector Inspection. Verify that the system should communicate with the front-ECU normally.







STEP 9. Check the wiring harness between front-ECU connector A-12X (terminal 30) and ETACS-ECU connector C-219 (terminal 59).






NOTE: Also check intermediate connector C-116 and joint connector C-02 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector C-116 or joint connector C-02 is damaged, repair or replace the damaged components) as described in Harness Connector Inspection.

Q: Is the wiring harness between front-ECU connector A-12X (terminal 30) and ETACS-ECU connector C-219 (terminal 59) in good condition?

YES: Go to Step 10.

NO: The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary. Verify that the system should communicate with the front-ECU normally.

STEP 10. Replace the ECU.

1. Replace the front-ECU.
2. The system should communicate with the front-ECU normally.

Q: Can the system communicate with the front-ECU?

YES: No action is necessary and testing is complete.

NO: Replace the ETACS-ECU. Verify that the system should communicate with the front-ECU normally.
pro multis · About Operation CHARM