DTC C1608: Implausible diagnosis data: Diagnosis

Required Special Tools: 

• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
  • MB991824: Vehicle Communication Interface (V.C.I.)
  • MB991827: M.U.T.-III USB Cable
  • MB991910: M.U.T.-III Main Harness A
• MB991974: ABS check harness

1. STEP 1. Using scan tool MB991958, diagnose the CAN bus lines. 

   Use scan tool to diagnose the CAN bus lines.

   Q: Is the check result normal? 

   1. YES:  Go to  Step 3.
   2. NO:  Repair the CAN bus lines (Refer to CAN BUS DIAGNOSTICS TABLE ). On completion, and then go to Step 2.
2. STEP 2. DTC recheck after resetting CAN bus lines 

   Q: Is DTC C1608 set? 

   1. YES:  Go to Step 3.
   2. NO:  The procedure is complete.
3. STEP 3. Battery check 

   Refer to BATTERY TEST .

   Q: Is the battery in good condition? 

   1. YES:  Go to  Step 5.
   2. NO:  Go to Step 4.
4. STEP 4. Charging system check 

   Refer to GENERATOR OUTPUT LINE VOLTAGE DROP TEST .

   Q: Is the charging system in good condition? 

   1. YES:  Replace the battery. Then go to  Step 9.
   2. NO:  Repair or replace the charging system component(s).
5. STEP 5. Voltage measurement at the A-03 ABS-ECU connector 
   1. Disconnect the connector, connect special tool ABS check harness (MB991974) to the harness-side connector, and measure the voltage at the special tool connector side.
      NOTE: Do not connect the special tool to ABS-ECU.
   2. Measure the voltage between terminal No. 26 and body ground.

      OK: Battery positive voltage 

   Q: Is the check result normal? 

   1. YES:  Go to  Step 7.
   2. NO:  Go to Step 6.
      Fig 1: Measuring Voltage Between Terminal No. 26 And Body Ground

      Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
6. STEP 6. Connector check: A-03 ABS-ECU connector 

   Q: Is the check result normal? 

   1. YES:  The open or short circuit may be present in the power supply circuit. Repair the wiring harness between the A-03 ABS-ECU connector terminal No. 26 and fusible link No. 27.
   2. NO:  Repair the defective connector.
7. STEP 7. Resistance measurement at A-03 ABS-ECU connector 
   1. Disconnect the ABS-ECU connector, connect special tool ABS check harness (MB991974) to the harness-side connector, and then measure the resistance at the special tool connector side.
      NOTE: Do not connect the special tool to ABS-ECU.
   2. Measure the resistance between terminal No. 1 and body ground, and between terminal No. 14 and body ground.

      OK: Continuity exists (2 Ω or less) 

   Q: Is the check result normal? 

   1. YES:  Go to  Step 9.
   2. NO:  Go to Step 8.
      Fig 2: Measuring Resistance Between Terminal No. 1 And Body Ground

      Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
8. STEP 8. Connector check: A-03 ABS-ECU connector 

   Q: Is the check result normal? 

   1. YES:  An open circuit may be present in the ground circuit. Repair the wiring harness between the A-03 ABS-ECU terminal No. 1 and body ground, and between the A-03 ABS-ECU terminal No. 14 and body ground.
   2. NO:  Repair the defective connector.
9. STEP 9. Check whether the DTC is reset. 
   1. Erase the DTC.
   2. Turn the ignition switch to the "LOCK" (OFF) position.
   3. Turn the ignition switch to the "ON" position.

   Q: Is DTC C1608 set? 

   1. YES:  Replace the hydraulic unit (integrated with ABS-ECU) (Refer to HYDRAULIC UNIT  ). Then go to Step 10.
   2. NO:  Go to  Step 11.
10. STEP 10. Check whether the DTC is reset. 

    Drive the vehicle at 20 km/h or more.

    Q: Is DTC C1608 set? 

    1. YES:  Return to  Step 1.
    2. NO:  Go to Step 11.
11. STEP 11. Check the other DTCs. 

    Drive the vehicle at 12mph (20 km/h) or higher.

    NOTE: The ABS warning light does not turn OFF in some cases unless the vehicle runs at 12mph (20 km/h) or higher.

    Q: Is any DTC set? 

    1. YES:  Carry out the applicable troubleshooting for the DTC (Refer to DIAGNOSTIC TROUBLE CODE CHART  ).
    2. NO:  The procedure is complete.