DTC U1000: OSS/KOS_OSS CAN Timeout: Diagnosis

STEP 1. Using scan tool (M.U.T.-IIISE), diagnose CAN bus line.
CAUTION: To prevent damage to scan tool (M.U.T.-IIISE), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-IIISE).
1. Connect scan tool (M.U.T.-IIISE). Refer to "HOW TO CONNECT THE SCAN TOOL (M.U.T.-IIISE) ."
2. Turn the ignition switch to the "ON" position.
3. Diagnose the CAN bus line.
4. Turn the ignition switch to the "LOCK" (OFF) position.
  Q: Is the CAN bus line found to be normal?
  
  YES: Go to Step 2.
  
  NO: Repair the CAN bus line (Refer to Troubleshooting - CAN BUS DIAGNOSTICS TABLE ).
STEP 2. Using scan tool (M.U.T.-IIISE), check whether the other system DTC is set.
Check whether an KOS & OSS-ECU "time-out" related DTC U1000 is set in other ECUs (Refer to CAN-RELATED DTC TABLE ).

Q: Is DTC set?

YES: Go to Step 3.

NO: Go to Step 4.
STEP 3. Using scan tool (M.U.T.-IIISE), check whether the DTC is set again.
Check again if the DTC is set in the TCU.
1. Erase the DTC.
2. Turn the ignition switch from OFF position to ON position.
3. Check the DTC.
  Q: Is the DTC set?
  
  YES: Replace the KOS & OSS-ECU.
  
  NO: A poor connection, open circuit or other intermittent malfunction is present in the CAN bus lines between the KOS & OSS-ECU and the TCU (Refer to How to use troubleshooting/Inspection Service Points - HOW TO COPE WITH INTERMITTENT MALFUNCTION ).
STEP 4. Using scan tool (M.U.T.-IIISE), check whether the DTC is set again.
Check again if the DTC is set in the TCU.
1. Erase the DTC.
2. Turn the ignition switch from OFF position to ON position.
3. Check the DTC.
  Q: Is the DTC set?
  
  YES: Replace the TCU (Refer to TCU ).
  
  NO: A poor connection, open circuit or other intermittent malfunction is present in the CAN bus lines between the KOS & OSS-ECU and the TCU (Refer to How to use troubleshooting/Inspection Service Points - HOW TO COPE WITH INTERMITTENT MALFUNCTION ).