Code No. U0141:
ETACS-ECU CAN communication time-out
caution
If diagnosis code No.U0141 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 air conditioner operation-related signal from the ETACS-ECU
via the CAN bus lines. If the A/C-ECU can not receive the air conditioner operation-related signal
at all on the ETACS-ECU, diagnosis code No.U0141 will be set.
COMMENTS ON TROUBLE SYMPTOM
Current trouble
Connector(s) or wiring harness in the CAN bus lines between the ETACS-ECU and the
A/C-ECU, the power supply system to the ETACS-ECU, the ETACS-ECU itself, or the A/C-ECU
may be faulty.
Past trouble
Carry out diagnosis with particular emphasis on connector(s) or wiring harness in
the CAN bus lines between the ETACS-ECU and the A/C-ECU, and the power supply system
to the ETACS-ECU. For diagnosis procedures, refer to "How to treat past trouble" (Refer to GROUP
00 -
How to Treat Past Trouble ).
note
For a past trouble, you can 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 Cope with Intermittent
Malfunction 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 -
CAN Bus Line Diagnostic Flow ).
caution
If the ignition switch is turned on without starting the engine
and then three minutes pass, the A/C-ECU may store U0141 as past trouble.
PROBABLE CAUSES
Damaged harness wires and connectors
Malfunction of ETACS-ECU
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 ETACS-related diagnosis code is set.
Q.
Is the diagnosis code set?
Diagnose the ETACS-ECU. 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 U0141: ETACS-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 ETACS-ECU, and then go to Step 6.
A poor connection, open circuit or other intermittent malfunction in the CAN bus
line between the ETACS-ECU 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 ETACS-ECU and the A/C-ECU (Refer to GROUP 00 -
How to Cope
with Intermittent Malfunction ).
STEP 6. Check whether the diagnosis code is reset.