Code No. U1109:
ETACS CAN time-out/Not equipped
caution |
If diagnosis code No.U1109 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 operation-related
signal from the ETACS-ECU via the CAN bus lines. If the auto A/C controller assembly (A/C-ECU)
cannot receive the air conditioner operation-related signal at all on the ETACS-ECU, diagnosis
code No.U1109 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 ETACS-ECU and the
auto A/C controller assembly (A/C-ECU), the power supply system to the ETACS-ECU, the ETACS-ECU
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 ETACS-ECU and the auto A/C controller assembly (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 ).
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caution |
If the ignition switch is turned on without starting the engine
and then three minutes pass, the A/C-ECU may set U1109 as past trouble.
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- Damaged wiring harness or connectors
- Malfunction of the ETACS-ECU
- 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 ETACS-related diagnosis code is set.
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Q.
Is the diagnosis code set?
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Diagnose the ETACS-ECU. (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
U1109: ETACS-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 ETACS-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 ETACS-ECU and the 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 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 ETACS-ECU and the auto A/C controller assembly (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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