Code
No.B2402: STL unit comm.(system ID) Code No.B2403: STL unit comm.(CRC) Code
No.B2404: STL unit comm.(function code) Code No.B2405: STL unit comm.(rolling code) Code
No.B2406: STL unit comm.(PTC operate) Code No.B2407: STL unit comm.(EEPROM) Code
No.B2408: STL unit comm.(solenoid)
caution
If the diagnosis
code No. B2402, B2403, B2404, B2405, B2406, B2407, or B2408 is set, diagnose the CAN bus lines.
Whenever the steering lock unit is replaced, ensure that the communication circuit
is normal.
DIAGNOSIS FUNCTION
When the ignition push switch is pressed, the steering lock unit communicates with KOS-ECU
to unlock the IG knob. However, if there is a failure shown below, the corresponding diagnosis
code is set.
B2402: System ID (vehicle specific code) failure
B2403: Cyclic Redundancy Check (CRC): The error detection strategy to detect a
continuously occurring error (burst error), the calculation result discrepancy
B2404: Function code failure
B2405: Rolling code (automatically changing a code for lock/unlock each
time when a lock operation is performed)
B2406: PTC thermistor continuously activated or activated to prevent solenoid abnormal
heating on the communication with steering lock unit
B2407: EEPROM failure
B2408: Communication error between the steering lock unit and KOS-ECU, or solenoid failure
TROUBLE JUDGMENT
Range of check
When the IG knob unlock communication is performed by pressing the ignition push
switch
Judgement criteria
B2402: Steering lock unit communication error (system ID) or received system ID
error
B2403: Steering lock unit communication error (CRC) or received frame CRC calculation
result discrepancy
B2404: Steering lock unit communication error (function code) or received frame
function code undefined
B2405: Steering lock unit communication error (rolling code) or received rolling
code out of the permissible range
B2406: Steering lock unit communication error (PTC operation) or PTC thermistor
activated to prevent solenoid abnormal heating
B2407: Steering lock unit communication error (EEPROM) or RRPROM failure
B2408: Steering lock unit communication error (solenoid) or solenoid failure
PROBABLE CAUSES
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 PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics
Use M.U.T.-III to diagnose the CAN bus lines.
Q.
Is the check result normal?
Go to Step 2.
Repair the CAN bus line (Refer to GROUP 54C -
Troubleshooting ).
On completion, go to Step 2.
STEP 3. Check the wiring harness between the C-211 key reminder switch
connector terminal No. 12, 9 and the C-104 KOS-ECU connector terminal No. 4, 5.
Check the signal lines for open circuit and short circuit.
Q.
Is the check result normal?
Go to Step 4.
Repair the wiring harness.
STEP 4. Replace the key reminder switch, and check whether the diagnosis
code is reset.
(1)Erase the diagnosis code.
(2)Turn the ignition switch from the LOCK (OFF) position to the ON position.
(3)Check if the diagnosis code is set.
Q.
Is the diagnosis code set?
Replace KOS-ECU and register the ID codes (Refer to ).
Intermittent malfunction is suspected (Refer to GROUP 00 -
How to Use
Troubleshooting/Inspection Service Points -
How to Deal with Intermittent
Malfunction ).
)
)
)
)
)
Go to Step 2.
Repair the CAN bus line (Refer to GROUP 54C -
Troubleshooting 
).
On completion, go to Step 2.