Code No.B2471 On hook button stuck
Code No.B2472 Off hook button stuck
C0de No.B2473 VR button stuck


caution
  • Before replacing the ECU, ensure that the communication circuit is normal.








JUDGMENT CRITERIA



PROBABLE CAUSES



  • Malfunctions of hands free-ECU
  • Malfunction of the CAN bus line
  • Malfunction of the steering wheel voice control switch
  • Malfunction of the steering wheel audio remote control switch
  • Malfunction of the audio unit <vehicles without MMCS> or audio visual navigation unit <vehicles with MMCS>
  • Damaged harness wires and connectors

DIAGNOSIS PROCEDURE

STEP 1. Check the audio unit <vehicles without MMCS> or audio visual navigation unit <vehicles with MMCS>.
Check that the audio unit <vehicles without MMCS> or audio visual navigation unit <vehicles with MMCS> works normally.

Q. Is the check result normal?
Go to Step 2.
Diagnose the audio unit <vehicles without MMCS> or audio visual navigation unit <vehicles with MMCS> (Refer to Radio and CD player - Diagnosis <vehicles without MMCS> or MMCS - Diagnosis <vehicles with MMCS>).

STEP 2. Check the steering wheel audio remote control switch.
Check that the audio unit <vehicles without MMCS> or audio visual navigation unit <vehicles with MMCS> can be operated normally using the steering wheel audio remote control switch.

Q. Is the check result normal?
Go to Step 3.
Diagnose the steering wheel audio remote control switch (Refer to <vehicles without MMCS> or <vehicles with MMCS>).

STEP 3. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.

Q. Is the check result normal?
Go to Step 4.
Repair the CAN bus line.

STEP 4. M.U.T.-III other system diagnosis code
Check the diagnosis code is set to the audio unit <vehicles without MMCS> or audio visual navigation unit <vehicles with MMCS>.

Q. Is the diagnosis code set?
Diagnose the audio unit <vehicles without MMCS> or audio visual navigation unit <vehicles with MMCS> (Refer to Radio and CD player - Diagnosis <vehicles without MMCS> or MMCS - Diagnosis <vehicles with MMCS>).
Go to Step 5.

STEP 5. Check the steering wheel voice control switch.
Refer to .

Q. Is the check result normal?
Go to Step 6.
Replace the steering wheel voice control switch.

STEP 6. Check the steering wheel audio remote control switch.
Refer to .

Q. Is the check result normal?
Go to Step 7.
Replace the steering wheel audio remote control switch.

STEP 7. Connector check: C-206 steering wheel voice control switch connector, C-213 steering wheel audio remote control switch connector

Q. Is the check result normal?
Go to Step 8.
Repair the defective connector.

STEP 8. Check the wiring harness between C-206 steering wheel voice control switch connector terminal No.3 and C-213 steering wheel audio remote control switch connector terminal No.3.

  • Check the communication lines for open circuit and short circuit.

Q. Is the check result normal?
Go to Step 9.
Repair the wiring harness.

STEP 9. Check the wiring harness between C-206 steering wheel voice control switch connector terminal No.2 and C-202 clock spring connector terminal No.4.

  • Check the communication lines for open circuit and short circuit.

Q. Is the check result normal?

    Go to Step 10.
Repair the wiring harness.

STEP 10. Check whether the diagnosis code is reset.
Check again if the diagnosis code is set to the hands free-ECU.
(1)Erase the diagnosis code.
(2)Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
(3)Check if diagnosis code is set.

Q. Is the diagnosis code set?
Go to Step 11.
The procedure is complete.

STEP 11. Temporarily replace the hands free-ECU, and check whether the diagnosis code is reset.
Check again if the diagnosis code is set to the hands free-ECU.
(1)Erase the diagnosis code.
(2)Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
(3)Check if diagnosis code is set.

Q. Is the check result normal?
Replace the hands free-ECU.
Replace the audio unit <vehicles without MMCS> or audio visual navigation unit <vehicles with MMCS>.