Keyless Operation System (KOS)

Code No.U1417 Implausible coding data

CAUTION:

- If diagnostic trouble code U1417 is set in KOS-ECU, always diagnose the CAN bus lines. If there is any fault in the CAN bus lines, an incorrect diagnostic trouble code may be set. In this case, the set diagnostic trouble code is not highly reliable.
- Before replacing the ECU, ensure that the communication circuit is normal.
- When the diagnostic trouble code U1417 is set in KOS-ECU, the diagnostic trouble code may also be set in ETACS-ECU. When the diagnostic trouble code is set in ETACS-ECU, carry out the diagnosis of the diagnostic trouble code for ETACS-ECU first.

CIRCUIT OPERATION

KOS-ECU receives the vehicle information stored in the ETACS-ECU via CAN bus lines.

DTC SET CONDITIONS

KOS-ECU communicates with ETACS-ECU via CAN bus lines. This diagnostic trouble code is set when the vehicle information received from the ETACS-ECU is invalid.

PROBABLE CAUSES

- Malfunction of ETACS-ECU
- Engine control module malfunction
- ETACS-ECUs have been interchanged between two vehicles.
- KOS-ECU malfunction
- External noise interference
- WCMs have been interchanged between two vehicles.

DIAGNOSIS

STEP 1. Using scan tool MB991958, diagnose the CAN bus line.

(1)
CAUTION:
To prevent damage to scan tool (MB991958), always turn the power supply mode of the engine switch to the OFF position before connecting or disconnecting scan tool (MB991958).

Connect scan tool MB991958. Refer to "How to connect the scan tool (M.U.T.-III) Reading and Clearing Diagnostic Trouble Codes."

(2)Turn the power supply mode of the engine switch to ON.

(3)Diagnose the CAN bus line.

(4)Turn the power supply mode of the engine switch to OFF.

Q. Is the CAN bus line found to be normal?

YES Go to Step 2.
NO Repair the CAN bus line CAN Bus Diagnostics Chart).
STEP 2. Using scan tool MB991958, read the other system diagnostic trouble code.

Check if DTC is set to the ETACS-ECU or engine control module.

Q. Is the DTC set?

YES (DTC is set to ETACS-ECU.) : Troubleshoot the ETACS Electronic Time and Alarm Control System (ETACS)).
YES (DTC is set to the engine control module.) : Troubleshoot the MFI system Multiport Fuel Injection (MFI)).
NO : Go to Step 3.
STEP 3. Check part number of ETACS-ECU.

Check the part number of ETACS-ECU.

OK: 8637A642


Q. Is the check result normal?

YES Go to Step 4.
NO Replace ETACS-ECU.
STEP 4. Check part number of KOS-ECU.

Check the part number of KOS-ECU.

OK: 8637A527


Q. Is the check result normal?

YES Go to Step 5.
NO Replace KOS-ECU and register the ID codes (Refer to ID Codes Registration Procedure).
STEP 5. Recheck for diagnostic trouble code.

Check again if the DTC is set to the KOS-ECU.

(1)Erase the DTC.

(2)Turn the power supply mode of the engine switch from OFF to ON.

(3)Check if DTC is set.

(4)Turn the power supply mode of the engine switch to OFF.

Q. Is the DTC set?

YES Replace KOS-ECU and register the ID codes (Refer to ID Codes Registration Procedure).
NO The trouble can be an intermittent malfunction How to Cope With Intermittent Malfunctions).