Electrical Power Steering System (EPS)
DTC U1417 Variant coding value invalid (includes faulty installation)
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 CAN Bus Diagnostics Chart ).
- Whenever ECU is replaced, ensure that the CAN bus lines are normal.
OPERATION
EPS-ECU receives variant coding data from the ETACS-ECU.
FUNCTION
The coding data is sent to the EPS-ECU for motor control.
TROUBLE JUDGEMENT
Check Conditions
- The power supply circuit system DTCs C1540, C1541 is not set.
- The ETACS circuit system DTC is not set.
Judgement Criterion
The abnormal coding data is sent from the ETACS-ECU, and the microcomputer determines that there is a problem in the system.
Fail Safe, Back Up Function
The EPS-ECU stops the motor control, then sets the DTC U1417.
PROBABLE CAUSES
- Malfunction of CAN bus line
- Malfunction of the EPS-ECU
- Malfunction of the ETACS-ECU
- Improperly installed EPS-ECU
DIAGNOSIS
STEP 1. Using scan tool MB991958, diagnose the CAN bus lines.
Use scan tool to diagnose the CAN bus lines.
Q. Is the check result normal?
YES Go to Step 3.
NO Repair the CAN bus lines CAN Bus Diagnostics Chart). 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.
Q. Is the DTC U1417 set?
YES Go to Step 3.
NO This diagnosis is complete.
STEP 3. Using scan tool MB991958, other system DTC
Use scan tool to check whether the ETACS-ECU-related or engine ECU-related DTC is set or not.
Q. Is any DTC set?
YES Troubleshoot for the relevant DTC.
NO Go to Step 4.
STEP 4. Check whether the DTC is reset.
(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.
Q. Is the DTC U1417 set?
YES Replace the EPS-ECU (Refer to Service and Repair). Then go to Step 5.
NO Intermittent malfunction How to Cope With Intermittent Malfunctions.
STEP 5. Check whether the DTC is reset.
(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.
Q. Is the DTC U1417 set?
YES Return to Step 1.
NO This diagnosis is complete.