[Previous][Next]
DTC U0100: Engine CAN timeout
 
 
caution
  • If DTC U0100 is set in the SRS-ECU, diagnose the CAN main bus line.
  • Whenever the ECU is replaced, ensure that the communication circuit is normal.
 
 
DIAGNOSTIC FUNCTION
If signal from the engine control module cannot be received for 500 milliseconds or more, the SRS-ECU stores DTC U0100.
 
 
TROUBLESHOOTING HINTS
  • Malfunction of the engine control module
  • Malfunction of the SRS-ECU
  • Malfunction of the CAN bus
 
 
DIAGNOSIS
STEP 1. Using scan tool (M.U.T.-IIISE), diagnose the CAN bus line
(1)
cautionTo prevent damage to scan tool (M.U.T.-IIISE), always turn off the power supply mode of the electric motor switch 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 ."
(2) Turn on the power supply mode of the electric motor switch.
(3) Diagnose the CAN bus line.
(4) Turn off the power supply mode of the electric motor switch.
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.-IIISE), read the other systems DTC.
Check if the DTC is set in the engine control module.
Is the DTC set?
Troubleshoot the engine (Refer to GROUP 13A - DTC Chart ).
Go to Step 3.
 
STEP 3. Using scan tool (M.U.T.-IIISE), read the other systems DTC.
Check if DTC U0100 is set in the ETACS-ECU.
Is the DTC set?
Go to Step 4.
Go to Step 5.
 
STEP 4. Recheck for DTC.
Check again if the DTC is set.
(1) Erase the DTC.
(2) Turn on the power supply mode of the electric motor switch.
(3) Check if the DTC is set.
(4) Turn off the power supply mode of the electric motor switch.
Is the DTC set?
Replace the engine control module. After replacing the ECU, carry out the CAN bus diagnostics. Then go to Step 6.
A poor connection, open circuit or other intermittent malfunction is present in the CAN bus lines between the engine control module and the SRS-ECU (Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).
 
STEP 5. Recheck for DTC.
Check again if the DTC is set.
(1) Erase the DTC.
(2) Turn on the power supply mode of the electric motor switch.
(3) Check if the DTC is set.
(4) Turn off the power supply mode of the electric motor switch.
Is the DTC set?
Replace the SRS-ECU. After replacing the ECU, carry out the CAN bus diagnostics. Then go to Step 6.
A poor connection, open circuit or other intermittent malfunction is present in the CAN bus lines between the engine control module and the SRS-ECU (Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).
 
STEP 6. Recheck for DTC.
Check again if the DTC is set.
(1) Erase the DTC.
(2) Turn on the power supply mode of the electric motor switch.
(3) Check if the DTC is set.
(4) Turn off the power supply mode of the electric motor switch.
Is the DTC set?
Return to Step 1.
The procedure is complete.