DTC U0100 Engine ECU CAN timeout DTC U0141 ETACS-ECU 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 (Refer to GROUP 54C, CAN Bus Diagnostics Table ).
Whenever ECU is replaced, ensure that the CAN bus lines are normal.
OPERATION
The signals from the engine control module (ECM) and ETACS-ECU are sent to the electric power steering-ECU.
FUNCTION
The signals from the engine control module (ECM) and ETACS-ECU are sent to the electric power steering-ECU for motor control.
TROUBLE JUDGMENT
Check Conditions
The power supply circuit system DTC (No. C1540, C1541) is not set.
The DTC related to engine circuit system and ETACS circuit system is set.
Judgment Criterion
The signals from the engine control module (ECM) and ETACS-ECU are not sent, and the microcomputer determines that there is a problem in the system.
Fail Safe, Back Up Function
The electric power steering-ECU sets DTC No. U0100 or U0141. If DTC No. U0100 is set, the ECU displays the electric power steering warning symbol to limit the power assistance.
PROBABLE CAUSES
Malfunction of CAN bus line
Malfunction of the electric power steering-ECU
Malfunction of the engine control module (ECM)
Malfunction of the ETACS-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 3.
Repair the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics Table ). On completion, go to Step 2.
STEP 2. DTC recheck after resetting CAN bus lines
(1) Erase the DTC.
(2) Turn the ignition switch from the "LOCK" (OFF) position to the "ON" position.
(3) Check if the DTC is set.
Is DTC U0100 or U0141 set?
Go to Step 3.
This diagnosis is complete.
STEP 3. Using scan tool MB991958, check the DTC.
Use scan tool to check if the same DTC (time-out) is set in the other ECU.
Is any DTC set?
(Code No. U0100 is set.) : Replace the Engine control module (ECM) (Refer to GROUP 13A - Troubleshooting/Inspection Chart for DTC <2.0L Engine> or GROUP 13C - Troubleshooting/Inspection Chart for DTC <2.4L Engine>), and then go to Step 4.
(Code No. U0141 is set.) : Replace the ETACS-ECU (Refer to GROUP 54A - ETACS .), and then go to Step 4.
(No DTC is set.) : Go to Step 4.
STEP 4. Check whether the DTC is set again.
(1) Erase the DTC.
(2) Turn the ignition switch from the LOCK (OFF) position to the ON position.
(3) Check if the DTC is set.
Is DTC U0100 or U0141 set?
Replace the electric power steering-ECU (Refer to ). Then go to Step 5.
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/How to Cope with Intermittent Malfunctions ).
STEP 5. Check whether the DTC is set again.
(1) Erase the DTC.
(2) Turn the ignition switch from the LOCK (OFF) position to the ON position.