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 Scan Tool Testing and Procedures).

- Whenever ECU is replaced, ensure that the CAN bus lines are normal.

OPERATION

- Electric power steering-ECU receives variant coding data from the ETACS-ECU.

FUNCTION

- The coding data is sent to the electric power steering-ECU for motor control.

TROUBLE JUDGMENT

Check Conditions

- The power supply circuit system DTC C1540, C1541 is not set.

- The ETACS circuit system DTC is not set.

Judgment Criterion

- The coding data from the ETACS-ECU are not matched twice consecutively.

- 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 electric power steering-ECU stops the motor control and illuminates the electric power steering warning display, then sets the DTC U1417.

PROBABLE CAUSES

- Malfunction of CAN bus line

- Malfunction of the electric power steering-ECU

- Malfunction of the ETACS-ECU

- Improperly installed electric power steering-ECU

DIAGNOSIS

Required Special Tools:

- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: Vehicle Communication Interface (V.C.I.)

- MB991827: M.U.T.-III USB Cable

- MB991910: M.U.T.-III Main Harness A (Vehicles with CAN communication system)

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 diagnostic trouble code

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 electric power steering-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.