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Inspection Procedure 17: Vehicle power cannot be turned "OFF."
 
 
cautionBefore replacing the ECU, ensure that the power supply circuit, the ground circuit and the communication circuit are normal.
 
 
 
 
COMMENTS ON TROUBLE SYMPTOM
If the power supply cannot be shut down by pressing the engine switch, the system may not receive any correct vehicle speed information via CAN or the IG1 power supply system may be defective.
If you cannot turn off the power supply, you may turn it off by an emergency stop of engine switch while keeping your foot on the brake pedal. The emergency stop of engine switch is pushing the engine switch 3 times in one second. If you cannot turn off the power supply, the door entry function or keyless entry function will not work. If the battery has the voltage greater than or equal to the certain voltage, the emergency key may lock each door and the liftgate. Pay attention to this case because the steering lock may not be locked.
When leaving the vehicle, move the shift lever to the P-position, and apply the parking brake surely.
 
 
PROBABLE CAUSES
  • Incorrect vehicle speed information (CAN signal)
  • Damaged wiring harness or connector (short to ground or short to power supply in IG1 line)
  • Malfunction of ETACS-ECU
  • Malfunction of engine switch
  • Malfunction of KOS&OSS-ECU
 
 
DIAGNOSIS
STEP 1. Battery check
Perform the battery test to check the battery status (Refer to GROUP 54A - Battery ).
Is the check result normal?
Go to Step 2.
Replace the battery.
 
STEP 2. Using scan tool (M.U.T.-IIISE), diagnose the CAN bus line
Use the scan tool (M.U.T.-IIISE) to diagnose the CAN bus lines.
Is the check result normal?
Go to Step 3.
Repair the CAN bus line (Refer to GROUP 54C - Diagnosis ).
 
STEP 3. Using scan tool (M.U.T.-IIISE), check the other system DTC.
Check whether the ECM sets a DTC.
Is the DTC set?
Diagnose the ECM (GROUP 13A - Diagnosis ).
Go to Step 4.
 
STEP 4. Using scan tool (M.U.T.-IIISE), check the other system data list
Check the ECM data list.
  • Item No.4: Vehicle speed (Refer to GROUP 13A - Data List Reference Table ).
Is the check result normal?
Go to Step 5.
Perform troubleshooting for ECM (GROUP 13A - Diagnosis ).
 
STEP 5. Voltage measurement at ETACS-ECU connector (IGS terminal)
(1) Measure the ETACS-ECU connector side by backprobing.
(2) Turn the power supply mode of the engine switch from "OFF" to "ON."
(3) Measure the voltage between the ETACS-ECU connector (IGS terminal) and body ground.
OK: The voltage should measure approximately 12 volts (battery positive voltage).
(4) Turn the power supply mode of the engine switch from "ON" to "OFF."
(5) Measure the voltage between the ETACS-ECU connector (IGS terminal) and body ground.
OK: 1 volt or less
Is the check result normal?
Go to Step 7.
Go to Step 6.
 
STEP 6. Check of short to power supply, short to ground or open circuit in IG1 line between the KOS&OSS-ECU connector and the ETACS-ECU connector
Is the check result normal?
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).
Repair the connector(s) or wiring harness.
 
STEP 7. Engine switch check
Continuity check of engine switch (Refer to ).
Is the check result normal?
Go to Step 8.
Replace the engine switch (Refer to ).
 
STEP 8. Check of the troubles
Check whether the engine is started (cranking is performed).
Is the check result normal?
Intermittent malfunction is suspected (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).
Replace the KOS&OSS-ECU and register the ID codes (Refer to ).