INSPECTION PROCEDURE 2: ABS/TCL-ECU Power Supply Circuit System: Diagnosis

Required Special Tools:

MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: MUT-III USB Cable
- MB991910: MUT-III Main Harness A
MB991997: ASC Check Harness

STEP 1. Measure the voltage at ABS/TCL-ECU connector A-03.
1. Disconnect the connector A-03, and connect special tool MB991997 to the wiring harness-side connector.
  NOTE: DO NOT connect special tool MB991997 to the ABS/TCL-ECU.
2. Turn the ignition switch to the "ON" position.
3. Measure the voltage between terminal 4 and ground. It should measure approximately 12 volts (battery positive voltage).
Q: Is battery positive voltage (approximately 12 volts) present?

YES : Go to Step 3.

NO : Go to Step 2.

Fig 1: Measuring Voltage Between Terminal 4 And Ground
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
STEP 2. Check ABS/TCL-ECU connector A-03, intermediate connector C-24, junction block connectors C-202, C-203 and ignition switch connector C-308 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
- ABS/TCL-ECU connector A-03
  
  Fig 2: Identifying Connector A-03 Terminals
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
- Intermediate connector C-24
  
  Fig 3: Identifying Connector A-24 Terminals
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
- Junction block connectors C-202 and C-203
  
  Fig 4: Identifying Connector C-202 & C-23 Terminals
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
- Ignition switch connector C-308
Q: Are the connectors and terminals in good condition?

YES : An open or short circuit may be present in the power supply line to the ABS/TCL-ECU. Repair the wiring harness between ABS/TCL-ECU connector A-03 terminal 4 and ignition switch connector C-308 terminal 4. Then go to Step 8.

NO : Repair or replace the damaged component(s). Refer to, HARNESS CONNECTOR INSPECTION . Then go to Step 8.

Fig 5: Identifying Ignition Switch Connector C-308
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
STEP 3. Measure the resistance at ABS/TCL-ECU connector A-03.
1. Disconnect the connector A-03, and connect special tool MB991997 to the wiring harness-side connector.
  NOTE: DO NOT connect special tool MB991997 to the ABS/TCL-ECU.
2. Measure the resistance between terminal 16, 47 and ground. It should be 2 ohms or less.
Q: Is the measured resistance 2 ohms or less?

YES : Go to Step 5.

NO : Go to Step 4.

Fig 6: Measuring Resistance Between Terminal 16, 47 And Ground
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
STEP 4. Check ABS/TCL-ECU connector A-03 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is ABS/TCL-ECU connector A-03 damaged?

YES : Repair or replace the damaged component(s). Refer to, HARNESS CONNECTOR INSPECTION . Then go to Step 8.

NO : An open circuit may be present in the ground circuit. Repair the wiring harness between ABS/TCL-ECU connector A-03 terminals 16, 47 and the body ground. Then go to Step 8.

Fig 7: Identifying Connector A-03 Terminals
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
STEP 5. Check the battery.
Check the battery (Refer to, BATTERY TEST ).

Q: Is the battery in good condition?

YES : Go to Step 6.

NO : Charge or replace the battery. Then go to Step 8.
STEP 6. Check the charging system.
Check the charging system (Refer to, CONNECTOR ENGAGEMENT INSPECTION ).

Q: Is the charging system in good condition?

YES : Go to Step 7.

NO : Repair or replace the charging system component(s).Then go to Step 8.
STEP 7. Retest the system.
Q: Can the ABS/TCL-ECU communicate with the scan tool (MUT-III Sub Assembly)?

YES : It can be assumed that this malfunction is intermittent. Refer to, How to Use Troubleshooting/Inspection Service Points - HOW TO COPE WITH INTERMITTENT MALFUNCTION .

NO : Replace the ABS/TCL-ECU. Then go to Step 8.
STEP 8. Retest the system.
Q: Can the ABS/TCL-ECU communicate with the scan tool (MUT-III Sub Assembly)?

YES : The procedure is complete.

NO : Go to Step 1.