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DTC U1000: OSS CAN timeout
 
 
caution
  • If DTC No. U1000 is set in the ETACS-ECU, always diagnose the CAN bus line.
  • Before replacing the ECU, ensure that the power supply circuit, the ground circuit and the communication circuit are normal.
 
 
DIAGNOSTIC FUNCTION
If the signal from OSS-ECU cannot be received, the ETACS-ECU sets DTC No. U1000.
 
 
JUDGMENT CRITERIA
After the following statuses continue to be true for 5 seconds, if the communication with the OSS-ECU cannot be established for 2,500 ms or more, the ETACS-ECU determines that a problem has occurred.
  • No abnormality is present to the network.
  • Ignition switch is in the ON position.
  • No abnormality is present to the power supply fuse (IOD fuse), or the odometer value is at 80.5 km (50.0 miles) or more.
  • ETACS-ECU system voltage is at 10-16 V.
 
 
TROUBLESHOOTING HINTS
  • The OSS-ECU may be defective
  • The ETACS-ECU may be defective
  • The CAN bus line may be defective
 
 
DIAGNOSIS
STEP 1. Using scan tool (M.U.T.-III), diagnose the CAN bus line.
(1)
cautionTo prevent damage to scan tool (M.U.T.-III), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-III).
Connect scan tool (M.U.T.-III). Refer to "How to connect the Scan Tool (M.U.T.-III) ."
(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 - Diagnosis ).
 
STEP 2. Using scan tool (M.U.T.-III), read the OSS diagnostic trouble code.
Check if DTC is set in the OSS-ECU.
Is the DTC set?
Troubleshoot the OSS (Refer to GROUP 42B - Troubleshooting ).
Go to Step 3.
 
STEP 3. Using scan tool (M.U.T.-III), read the KOS diagnostic trouble code.
Check if DTC No. U1000 is set in the KOS-ECU.
Is the DTC set?
Go to Step 4.
Go to Step 5.
 
STEP 4. Recheck for diagnostic trouble code.
Check again if the DTC is set in the ETACS-ECU.
(1) Erase the DTC.
(2) Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
(3) Check if DTC is set.
Is the DTC set?
Replace the OSS-ECU.
The trouble can be an intermittent malfunction such as a poor connection or open circuit in the CAN bus lines between the OSS-ECU and the ETACS-ECU (GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
 
STEP 5. Recheck for diagnostic trouble code.
Check again if the DTC is set in the ETACS-ECU.
(1) Erase the DTC.
(2) Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
(3) Check if DTC is set.
Is the DTC set?
Replace the ETACS-ECU.
The trouble can be an intermittent malfunction such as a poor connection or open circuit in the CAN bus lines between the OSS-ECU and the ETACS-ECU (GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).