Code No. U0197: Hands Free Module Time-out



caution If diagnosis code U0197 is set in the A/C-ECU, diagnose the CAN main bus line.
caution Whenever the ECU is replaced, ensure that the communication circuit is normal.


TROUBLE JUDGMENT


The A/C-ECU receives the air conditioner control-related signals from the hands-free module via the CAN bus lines. If any of the air conditioner control-related signals from the SRS-ECU cannot be received, diagnosis code U0197 is stored.

TECHNICAL DESCRIPTION (COMMENT)


Current trouble
Past trouble

PROBABLE CAUSES



  • Damaged harness wires and connectors
  • Malfunction of audio
  • Malfunction of the A/C-ECU

DIAGNOSIS PROCEDURE


STEP 1. 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 2
Repair the CAN bus lines. (Refer to GROUP 54C, Troubleshooting ). On completion, go to Step 6.

STEP 2. M.U.T.-III other system diagnosis code


Check whether the audio-related diagnosis code is set.

Q. Is the diagnosis code set?

Diagnose the audio. Refer to .
Go to Step 3

STEP 3. M.U.T.-III other system diagnosis code


Check if a diagnosis code, which relates to CAN communication-linked systems below, is set.

  • combination meter
    U0184: audio-related time-out diagnosis code

Q. Is the diagnosis code set?

Go to Step 4
Go to Step 5

STEP 4. Check whether the diagnosis code is reset.


Recheck if the diagnosis code is set.
(1)Erase the diagnosis code.
(2)Ignition switch: LOCK (OFF) to ON
(3)Check if the diagnosis code is set.

Q. Is the diagnosis code set?

Replace the audio, and then go to Step 6.
A poor connection, open circuit or other intermittent malfunction in the CAN bus line between the audio and the A/C-ECU. (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).

STEP 5. Check whether the diagnosis code is reset.


Recheck if the diagnosis code is set.
(1)Erase the diagnosis code.
(2)Ignition switch: LOCK (OFF) to ON
(3)Check if the diagnosis code is set.

Q. Is the diagnosis code set?

Replace the A/C-ECU, and then go to Step 6.
A poor connection, open circuit or other intermittent malfunction in the CAN bus line between the audio and the A/C-ECU. (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).

STEP 6. Check whether the diagnosis code is reset.


Recheck if the diagnosis code is set.
(1)Erase the diagnosis code.
(2)Ignition switch: LOCK (OFF) to ON
(3)Check if the diagnosis code is set.

Q. Is the diagnosis code set?

Return to Step 1.
The procedure is complete.