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DTC B2401: Keyless/KOS key ID not registered
 
 
caution
  • If the DTC B2401 is set, be sure to diagnose the CAN bus line.
  • When replacing the ECU, always check that the communication circuit is normal.
 
 
DIAGNOSTIC FUNCTION
If no keyless operation key ID is registered with KOS-ECU or if the keyless operation key with ID not registered is used, KOS-ECU sets the DTC B2401.
 
 
JUDGMENT CRITERIA
If the number of the registered keyless operation keys is 0, or the registration of a keyless operation key fails when the number of the registered keyless operation keys is 0, it is judged as abnormal.
 
 
PROBABLE CAUSES
  • Malfunction of CAN bus line
  • The registration of a keyless operation key ID fails when no keyless operation key ID is registered.
  • Malfunction of the keyless operation key
  • Malfunction of KOS-ECU
 
 
DIAGNOSIS
STEP 1. Using scan tool MB991958, diagnose the CAN bus line.
(1)
cautionTo 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 scan tool (M.U.T.-III) ."
(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.
Is the CAN bus line found to be normal?
Go to Step 2.
Repair the CAN bus line (Refer to GROUP 54C, Diagnosis ).
 
STEP 2. Register the keyless operation key ID and recheck the diagnostic trouble code.
Register the keyless operation key ID (refer to ), and check whether the DTC is reset.
(1) Turn the power supply mode of the engine switch from OFF to ON.
(2) Check if the DTC is set.
Is the DTC set?
Go to Step 3.
The procedure is complete.
 
STEP 3. Replace the keyless operation key and recheck the diagnostic trouble code.
Replace the keyless operation key for which the DTC is set with a new one, register the encrypted code and keyless operation key ID (refer to ), and check whether the DTC is reset.
(1) Turn the power supply mode of the engine switch from OFF to ON.
(2) Check if the DTC is set.
Is the DTC set?
Replace KOS-ECU and register the ID codes (Refer to ).
The procedure is complete.