If the diagnosis
code No. U0164 is set, be sure to diagnose the CAN bus line.
When replacing the radio and CD player, always check that the communication circuit
is normal.
DIAGNOSTIC FUNCTION
If the signal from heater controller assembly (A/C-ECU) cannot be received, the
radio and CD player sets the diagnosis code No. U0164.
JUDGEMENT CRITERIA
With the statuses that the ignition switch is at ON position, system voltage is 10-16
V (data from ETACS-ECU), and there is no malfunction to the power supply fuse (IOD fuse), or odometer
value is 80.5 km or more, if the communication with A/C-ECU cannot be established for
2,500 ms or more, the radio and CD player determines that a problem has occurred.
PROBABLE CAUSES
Malfunction of CAN bus line
Malfunction of heater controller assembly
Malfunction of radio and CD player
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 line (Refer to GROUP 54C - Troubleshooting ).
STEP 2. M.U.T.-III other system diagnosis code
Check if diagnosis code is set to the A/C-ECU.
Q.
Is the diagnosis code set?
Troubleshoot the A/C-ECU (Refer to GROUP 55 - Troubleshooting ),
and then go to Step 3.
Go to Step 3.
STEP 3. Check the M.U.T.-III Diagnosis code for other systems
Check if the diagnosis code No. U0164 is set to ETACS-ECU.
Q.
Is the diagnosis code set?
Go to Step 4.
Go to Step 5.
STEP 4. Diagnosis code recheck
Check again if the diagnosis code is set to the radio and CD player.
(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 the heater controller assembly.
A poor connection, open circuit or other intermittent malfunction in the CAN bus
line between the radio and CD player and the heater controller assembly (A/C-ECU).
(Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points
- How to Cope with Intermittent Malfunction .)
STEP 5. Check whether the diagnosis code is reset.
Check again if the diagnosis code is set to the radio and CD player.
(1)Erase the diagnosis code.
(2)Turn the ignition switch from the "LOCK" (OFF) position to the "ON" position.
(3)Check if diagnosis code is set.
Q.
Is the diagnosis code set?
Replace the radio and CD player.
A poor connection, open circuit or other intermittent malfunction in the CAN bus
line between the radio and CD player and the heater controller assembly (A/C-ECU).
(Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points
- How to Cope with Intermittent Malfunction .)