If diagnosis
code U1110 is set in the multi display station, always diagnose the CAN bus lines.
Whenever the ECU is replaced, ensure that the communication circuit is normal.
TROUBLE JUDGMENT
When the multi display station can not receives necessary signals from the A/C-ECU
via CAN bus lines. If the multi display station can not receives the necessary A/C-ECU
signals, diagnosis code U1110 will be set.
COMMENTS ON TROUBLE SYMPTOM
Current trouble
Connector(s) or wiring harness in the CAN bus lines between the A/C-ECU
and the multi display station, the power supply system to the multi display station, the multi
display station itself, or the A/C-ECU may be defective.
Past trouble
Carry out diagnosis with particular emphasis on connector(s) or wiring harness in
the CAN bus lines between the A/C-ECU and the multi display station, and the power
supply system to the A/C-ECU. For diagnosis procedures, refer to "How to cope with
past trouble" (Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points ).
note
For a past trouble, you may not find it by the M.U.T.-III CAN bus diagnostics even if
there is any failure in CAN bus lines. In this case, refer to GROUP 00, How to Use Troubleshooting/Inspection
Service Points -
How to Cope with Intermittent Malfunctions ).
and check the CAN bus lines. You can narrow down the possible cause of the trouble by referring
to the diagnosis code, which is set regarding the CAN communication-linked ECUs (Refer to GROUP
54C, Explanation about the M.U.T.-III CAN Bus Diagnostics ).
POSSIBLE CAUSES
Damaged harness wires and connectors
Malfunction of A/C-ECU
Malfunction of multi display station
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 satisfactory?
Go to Step 2.
Repair the CAN bus lines (Refer to GROUP 54C, Diagnosis -
Can Bus Diagnostics
Table ). On completion, go to Step 6.
STEP 2. M.U.T.-III other system diagnosis code
Check if an A/C system diagnosis code is set.
Q.
Is the diagnosis code set?
Diagnose the A/C system (Refer to GROUP 55, Troubleshooting ).
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.
Engine-ECU
Code No.U1110: A/C-ECU time-out
ETACS-ECU
Code No.013: A/C-ECU time-out
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)Turn the ignition switch to "ON" position.
(3)Check if the diagnosis code is set.
Q.
Is the check result satisfactory?
A poor connection, open circuit or other intermittent malfunction is present in
the CAN bus lines between the A/C-ECU and the multi display station (Refer to GROUP
00, How to Use Troubleshooting/Inspection Service Points -
How to Cope with Intermittent
Malfunctions ).
Replace A/C-ECU and then go to step 6.
STEP 5. Check whether the diagnosis code is reset.
Recheck if the diagnosis code is set.
(1)Erase the diagnosis code.
(2)Turn the ignition switch to "ON" position.
(3)Check if the diagnosis code is set.
Q.
Is the check result satisfactory?
A poor connection, open circuit or other intermittent malfunction is present in
the CAN bus lines between the A/C-ECU and the multi display station (Refer to GROUP
00, How to Use Troubleshooting/Inspection Service Points -
How to Cope with Intermittent
Malfunctions ).
Replace multi display station and then go to step 6.
STEP 6. Check whether the diagnosis code is reset.
).
