Code No.U1108
Meter CAN timeout/Not equipped
caution |
If diagnosis code No.U1108 is set in the auto A/C controller
assembly (A/C-ECU), diagnose the CAN main bus line.
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caution |
Whenever the ECU is replaced, ensure that the communication
circuit is normal.
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The auto A/C controller assembly (A/C-ECU) receives air conditioner control-related signals
from the combination meter via the CAN bus lines. If the ECU cannot receive any of the air conditioner
control-related signals from the combination meter, diagnosis code U1108 will be set.
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COMMENTS ON TROUBLE SYMPTOM
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Current trouble
- Connector(s) or wiring harness in the CAN bus lines between the combination meter
and the auto A/C controller assembly (A/C-ECU), the power supply system to the combination meter,
the combination meter itself, or the auto A/C controller assembly (A/C-ECU) may be faulty.
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Past trouble
- Carry out diagnosis with particular emphasis on connector(s) or wiring harness in
the CAN bus lines between the auto A/C controller assembly (A/C-ECU) and the combination meter,
and the power supply system to the combination meter. 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 ).
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caution |
If the ignition switch is turned to the ON position without starting
the engine, the diagnosis code U1108 (past trouble) may be set to the A/C-ECU after
three minutes.
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- Damaged wiring harness or connectors
- Malfunction of the combination meter
- Malfunction of the auto A/C controller assembly (A/C-ECU)
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STEP 1. M.U.T.-III CAN bus diagnostics
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Use the M.U.T.-III to diagnose the CAN bus lines.
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Q.
Is the check result normal?
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Go to Step 2.
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Repair the CAN bus lines (Refer to GROUP 54C Troubleshooting ).
On completion, go to Step 6.
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STEP 2. M.U.T.-III other system diagnosis code
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Check whether the combination meter-related diagnosis code is set.
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Q.
Is the diagnosis code set?
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Diagnose the combination meter. (Refer to GROUP 54A Troubleshooting ).
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Go to Step 3.
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STEP 3. M.U.T.-III other system diagnosis code
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Check if a diagnosis code, which relates to CAN communication-linked systems below, is
set.
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- ETACS-ECU
U1108: combination meter-related time-out diagnosis code
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Q.
Is the diagnosis code set?
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Go to Step 4.
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Go to Step 5.
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STEP 4. Check whether the diagnosis code is set again.
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Recheck if the diagnosis code is set.
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(1)Erase the diagnosis code.
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(2)Ignition switch: "LOCK" (OFF) to "ON"
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(3)Check if the diagnosis code is set.
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Q.
Is the diagnosis code set?
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Replace the auto A/C controller assembly (A/C-ECU), and then go to Step 6.
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A poor connection, open circuit or other intermittent malfunction in the CAN bus
line between the combination meter and auto A/C controller assembly (A/C-ECU) (Refer to GROUP
00 - How to Cope with Intermittent Malfunction ).
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STEP 5. Check whether the diagnosis code is set again.
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Recheck if the diagnosis code is set.
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(1)Erase the diagnosis code.
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(2)Ignition switch: "LOCK" (OFF) to "ON"
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(3)Check if the diagnosis code is set.
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Q.
Is the diagnosis code set?
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Replace the meter and auto A/C controller assembly (A/C-ECU), and then go to Step
6.
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A poor connection, open circuit or other intermittent malfunction in the CAN bus
line between the combination meter and the meter and A/C-ECU (Refer to GROUP 00 - How
to Cope with Intermittent Malfunction ).
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STEP 6. Check whether the diagnosis code is set again.
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Recheck if the diagnosis code is set.
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(1)Erase the diagnosis code.
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(2)Ignition switch: "LOCK" (OFF) to "ON"
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(3)Check if the diagnosis code is set.
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Q.
Is the diagnosis code set?
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Return to Step 1.
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The procedure is complete.
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