B2471
DTC B2471: On Hook Button StuckDTC B2472: Off Hook Button Stuck
DTC B2473: VR Button Stuck
CAUTION: Before replacing the module, ensure that the communication circuit is normal.
Steering Wheel Voice Control Switch Circuit [Vehicles Without MMCS]:
Steering Wheel Voice Control Switch Circuit [Vehicles With MMCS]:
JUDGMENT CRITERIA
When the hands free module receives any switch signal from the speech switch, pick-up switch, hang-up switch of steering wheel voice control switch for approximately 1 or 2 minutes continuously, it stores diagnostic trouble code B2471 (hang-up switch), B2472 (pick-up switch) or B2473 (speech switch) for each switch.
PROBABLE CAUSES
- Damaged harness wires and connectors
- The hands free module may be defective.
- The microphone unit may be defective.
- The CAN bus line may be defective.
- The steering wheel voice control switch may be defective.
- The radio and CD player [vehicles without MMCS] or multivision display [vehicles with MMCS] may be defective.
DIAGNOSIS
Required Special Tools:
- MB991223: Harness Set
- MB992006: Extra Fine Probe
- 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. Check the radio and CD player [vehicles without MMCS] or multivision display [vehicles with MMCS].
Check that the radio and CD player [vehicles without MMCS] or multivision display [vehicles with MMCS] works normally.
Q: Is the check result normal?
YES : Go to Step 2.
NO : Diagnose the radio and CD player [vehicles without MMCS] or multivision display [vehicles with MMCS] (Refer to Radio and CD player - Diagnosis Trouble Symptom Chart [vehicles without MMCS] or MMCS - Diagnosis Trouble Symptom Chart [vehicles with MMCS]).
STEP 2. Check the steering wheel audio remote control switch.
Check that the radio and CD player [vehicles without MMCS] or multivision display [vehicles with MMCS] can be operated normally using the steering wheel audio remote control switch.
Q: Is the check result normal?
YES : Go to Step 3.
NO : Diagnose the steering wheel audio remote control switch (Refer to Inspection Procedure 1 [vehicles without MMCS] or Inspection Procedure 2 [vehicles with MMCS]).
STEP 3. Using scan tool MB991958, diagnose the CAN bus line.
Use scan tool MB991958 to diagnose the CAN bus lines.
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.
1. Connect scan tool MB991958. Refer to "How to connect the Scan Tool (M.U.T.-III)." How to Connect the Scan Tool (M.U.T.-III)
2. Turn the ignition switch to "ON" position.
3. Diagnose the CAN bus line.
Q: Is the check result normal?
YES : Go to Step 4.
NO : Repair the CAN bus line.
STEP 4. Using scan tool MB991958, read the radio and CD player [vehicles without MMCS] or CAN box unit [vehicles with MMCS] diagnostic trouble code.
Check the diagnostic trouble code is set to the radio and CD player [vehicles without MMCS] or CAN box unit [vehicles with MMCS].
1. Turn the ignition switch to the "ON" position.
2. Check for radio and CD player [vehicles without MMCS] or CAN box unit [vehicles with MMCS] DTCs.
3. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Diagnose the radio and CD player [vehicles without MMCS] or multivision display [vehicles with MMCS] (Refer to Radio and CD player - Diagnosis Diagnostic Trouble Code Descriptions [vehicles without MMCS] or MMCS - Diagnosis Diagnostic Trouble Code Descriptions [vehicles with MMCS]), and then go to Step 3.
NO : Go to Step 5.
STEP 5. Check the steering wheel voice control switch.
Refer to Steering Wheel Voice Control Switch Check. Steering Wheel Voice Control Switch Continuity Check
Q: Is the check result normal?
YES : Go to Step 6.
NO : Replace the steering wheel voice control switch.
STEP 6. Check the steering wheel audio remote control switch.
Refer to Steering Wheel Audio Remote Control Switch Check. Component Tests and General Diagnostics
Q: Is the check result normal?
YES : Go to Step 7.
NO : Replace the steering wheel audio remote control switch.
STEP 7. Check steering wheel audio remote control switch connector C-213 and steering wheel voice control switch connector C-206 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Are wheel audio remote control switch connector C-213 and steering wheel voice control switch connector C-206 in good condition?
YES : Go to Step 8.
NO : Repair the defective connector.
STEP 8. Check the wiring harness between steering wheel voice control switch connector C-206 (terminal 3) and steering wheel audio remote control switch connector C-213 (terminal 3).
- Check the communication lines for open circuit and short circuit.
Q: Is the wiring harness between steering wheel voice control switch connector C-206 (terminal 3) and steering wheel audio remote control switch connector C-213 (terminal 3) in good condition?
YES : Go to Step 9.
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 9. Check the wiring harness between steering wheel voice control switch connector C-206 (terminal 2) and clock spring connector C-202 (terminal 4).
- Check the communication lines for open circuit and short circuit.
Q: Is the wiring harness between steering wheel voice control switch connector C-206 (terminal 2) and clock spring connector C-202 (terminal 4) in good condition?
YES : Go to Step 10.
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 10. Recheck for diagnostic trouble code.
Check again if the DTC is set to the hands free module
1. Erase the DTC.
2. Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
3. Check if DTC is set.
Q: Is the DTC set?
YES : Go to Step 11.
NO : The trouble can be an intermittent malfunction.
STEP 11. Temporarily replace the hands free module, and check whether the diagnostic trouble code is reset.
Check again if the DTC is set to the hands free module
1. Erase the DTC.
2. Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
3. Check if DTC is set.
Q: Is the DTC set?
YES : Replace the radio and CD player [vehicles without MMCS] or multivision display [vehicles with MMCS].
NO : Replace the hands free module.