Code No.U1110
A/C CAN timeout/Not equipped
caution |
- If diagnosis
code No.U1110 is set in the ETACS-ECU, diagnose the CAN main bus line.
- Whenever the ECU is replaced, ensure that the input and output signal circuits are normal.
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TROUBLE JUDGEMENT
If signal from the A/C-ECU cannot be received for 500 milliseconds or more, the
ETACS-ECU sets diagnosis code No. U1110.
PROBABLE CAUSES
- Malfunction of the A/C-ECU
- Malfunction of the ETACS-ECU
- Malfunction of the CAN bus
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
).
On completion, go to Step 5.
STEP 2. Check the M.U.T.-III Diagnosis code for other systems
Check that the A/C-ECU set a diagnosis code.
Q.
Is the diagnosis code set?
Diagnose the A/C-ECU. Refer to GROUP 55B, Troubleshooting
.
Go to Step 3.
STEP 3. Check whether the diagnosis code is reset.
Check again if the diagnosis code is set to the ETACS-ECU.
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(1)Erase the diagnosis code.
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(2)Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
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(3)On completion, check that the diagnosis code is reset.
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Q.
Is the diagnosis code set?
Replace the A/C-ECU. After replacing the ECU, carry out the CAN bus diagnostics. Then
go to Step 4.
A poor connection, open circuit or other intermittent malfunction is present in
the CAN bus lines between the A/C-ECU and the ETACS-ECU (Refer to GROUP 00, How to
Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions
).
STEP 4. Check whether the diagnosis code is reset.
Check again if the diagnosis code is set to the ETACS-ECU.
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(1)Erase the diagnosis code.
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(2)Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
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(3)On completion, check that the diagnosis code is not reset.
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Q.
Is the diagnosis code set?
Replace the ETACS-ECU. After replacing the ECU, carry out the CAN bus diagnostics.
Then go to Step 5.
A poor connection, open circuit or other intermittent malfunction is present in
the CAN bus lines between the A/C-ECU and the ETACS-ECU (Refer to GROUP 00, How to
Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions
).
STEP 5. Check whether the diagnosis code is reset.
Recheck if the diagnosis code is set to the ETACS-ECU.
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(1)Erase the diagnosis code.
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(2)Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
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(3)On completion, check that the diagnosis code is reset.
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Q.
Is the diagnosis code set?
Return to Step 1.
The procedure is complete.