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DTC U1000: OSS/KOS_OSS CAN timeout <Vehicles with KOS>
 
 
caution
  • If DTC U1000 is set, be sure to diagnose the CAN bus line.
  • Before replacing the ECU or combination meter, ensure that the power supply circuit, the ground circuit and the communication circuit are normal.
 
 
DIAGNOSTIC FUNCTION
If the signal from KOS&OSS-ECU cannot be received, the combination meter sets DTC U1000.
 
 
JUDGMENT CRITERIA
With the ignition switch is at ON position, DTC U1190 is not set and DTC U1195 is not set, if the communication with KOS&OSS-ECU cannot be established for 2500 ms or more, the combination meter determines that a problem has occurred.
 
 
TROUBLESHOOTING HINTS
  • The CAN bus line may be defective
  • The KOS&OSS-ECU may be defective
  • The combination meter may be defective
 
 
DIAGNOSIS
STEP 1. Using scan tool (M.U.T.-IIISE), diagnose CAN bus line.
(1)
cautionTo 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).
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.
Is the CAN bus line found to be normal?
Go to Step 2.
Repair the CAN bus line (Refer to GROUP 54C - Troubleshooting - CAN Bus Diagnostics Table ).
 
STEP 2. Using scan tool (M.U.T.-IIISE), check whether the other system DTC is set.
Check if DTC is set in the KOS&OSS-ECU.
Is the DTC set?
Troubleshoot the KOS&OSS-ECU (Refer to GROUP 42B - Troubleshooting ).
Go to Step 3.
 
STEP 3. Using scan tool (M.U.T.-IIISE), check whether the other system DTC is set.
Check if a DTC, which relates to CAN communication-linked systems below, is set.
  • ETACS-ECU
    • DTC U1000 OSS/KOS_OSS CAN timeout
Is the DTC set?
Go to Step 4.
Go to Step 5.
 
STEP 4. Using scan tool (M.U.T.-IIISE), check whether the DTC is set again.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) On completion, check that the DTC is not set again.
Is the DTC set?
Replace KOS&OSS-ECU.
A poor connection, open circuit or other intermittent malfunction is present in the CAN bus lines between the KOS&OSS-ECU and the combination meter (Refer to GROUP 00 - How to use troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).
 
STEP 5. Using scan tool (M.U.T.-IIISE), check whether the DTC is set again.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) On completion, check that the DTC is not set again.
Is the DTC set?
Replace combination meter.
A poor connection, open circuit or other intermittent malfunction is present in the CAN bus lines between the KOS&OSS-ECU and the combination meter (Refer to GROUP 00 - How to use troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).