B2409

DTC B2409: STL unit comm.(No response)

CAUTION:

- If the DTC B2409 is set, diagnose the CAN bus lines.

- Whenever the steering lock unit is replaced, ensure that the communication circuit is normal.













DTC SET CONDITION

When the ignition push switch is pressed, the steering lock unit communicates with KOS-ECU to unlock the IG knob. If the steering lock unit communication error (no response) occurs at this time, the DTC is set.

TECHNICAL DESCRIPTION (COMMENT)

When the IG knob unlock communication is performed by pressing the ignition push switch, if the steering lock unit communication error (no response) occurs, the steering lock unit is judged as abnormal.

TROUBLESHOOTING HINTS

- Malfunction of the key reminder switch (integrated into the steering lock unit)

- Wiring harness or connector failure of CAN bus line

- Malfunction of the KOS-ECU

DIAGNOSIS

Required Special Tools:

- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: Vehicles 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 line.





(1)
CAUTION:
To prevent damage to scan tool (MB991958), always turn the ignition switch to the "LOCK"
(OFF) position before connecting or disconnecting scan tool (MB991958).

Connect scan tool MB991958 to the data link connector.
(2)Turn the ignition switch to the "ON" position.
(3)Diagnose the CAN bus line.
(4)Turn the ignition switch to the "LOCK" (OFF) position.

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. Check key reminder switch connector C-213 and KOS-ECU connector C-31 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q. Is the key reminder switch connector C-213 and KOS-ECU connector C-31 in good condition?

YES Go to Step 3.
NO Repair the defective connector.
STEP 3. Check the wiring harness between the key reminder switch connector C-213 (terminal No. 12, 9, 11) and the KOS-ECU connector C-31 (terminal No. 4, 5, 31).

- Check the signal lines for open circuit and short circuit.

Q. Is the wiring harness between key reminder switch connector C-213 (terminal No. 12, 9, 11) and the KOS-ECU connector C-31 (terminal No. 4, 5, 31) in good condition?

YES Go to Step 4.
NO The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary.
STEP 4. Replace the key reminder switch, and check whether the diagnostic trouble code 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 set?

YES Replace KOS-ECU and register the ID codes (Refer to ID registration procedure manual - ID codes registration judgement table).
NO The trouble can be an intermittent malfunction How to Cope With Intermittent Malfunctions).