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DTC U0100 Engine CAN timeout
 
 
caution
  • If there is any problem in the CAN bus lines, an incorrect DTC may be set. Prior to this diagnosis, diagnose the CAN bus lines.
  • Whenever the ECU is replaced, ensure that the CAN bus lines are normal.
 
 
OPERATION
FCM/LDW/AHB-ECU communicates with the ECM via the CAN bus lines.
 
 
DTC SET CONDITION
This DTC is set when the abnormality below is detected:
  • The signal sent from the ECM cannot be received for a certain period.
 
 
PROBABLE CAUSES
  • Malfunction of the CAN bus line
  • Malfunction of the ECM power supply circuit
  • Malfunction of the ECM
  • Malfunction of the FCM/LDW/AHB-ECU
 
 
DIAGNOSIS
STEP 1. Using scan tool MB991958, diagnose the CAN bus lines.
Use scan tool to diagnose the CAN bus lines.
Is the check result normal?
Go to Step 2.
Repair the CAN bus lines (Refer to GROUP 54C - Troubleshooting ).
 
STEP 2. Scan tool other system DTC.
Check if DTC U0100 is set in other ECU.
Is the DTC set?
Go to Step 3.
Go to Step 4.
 
STEP 3. Check whether the DTC is set again.
Check again if the DTC is set in the FCM/LDW/AHB-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 engine control module (Refer to GROUP 13A - ECM <2.0L Engine>, GROUP 13C - ECM <2.4L Engine>).
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
 
STEP 4. Check whether the DTC is set again.
Check again if the DTC is set in the FCM/LDW/AHB-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 FCM/LDW/AHB-ECU (Refer to ).
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).