Code No.U0101 T/M CAN timeout
caution |
- If diagnosis code No. U0101 is set to the ETACS-ECU, always diagnose the CAN bus line.
- Before replacing the ECU, ensure that the power supply circuit, the earth circuit and the communication circuit are normal.
- When the ETACS-ECU of vehicles without KOS is replaced, the encrypted code of the ignition key needs to be registered to the ETACS-ECU. (If the encrypted code is not registered, the engine cannot be started. Register the encrypted code as described in Immobilizer System - How to Register Key ID
.)
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DIAGNOSTIC FUNCTION
If the signal from CVT-ECU or A/T-ECU cannot be received, the ETACS-ECU sets the diagnosis code No. U0101.
JUDGEMENT CRITERIA
After the following statuses continue to be true for 5 seconds, if the communication with the CVT-ECU or A/T-ECU cannot be established for 600 ms or more, the ETACS-ECU determines that a problem has occurred.
- No abnormality is present to the network.
- Ignition switch is in the ON position.
- No abnormality is present to the power supply fuse (IOD fuse), or the odometer value is at 80.5 km or more.
- ETACS-ECU system voltage is at 10-16 V.
PROBABLE CAUSES
- Malfunction of CVT-ECU or A/T-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
).
STEP 2. M.U.T.-III other system diagnosis code
Check if diagnosis code is set to the CVT-ECU or A/T-ECU.
Q.
Is the diagnosis code set?
Troubleshoot the CVT or automatic transmission (FF). Refer to GROUP 23A - Diagnosis code chart
or GROUP 23C -Troubleshooting
.
Go to Step 3
STEP 3. M.U.T.-III other system diagnosis code
Check if the diagnosis code No. U0101 is set to the engine-ECU.
Q.
Is the diagnosis code set?
Go to Step 4
Go to Step 5
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)Check if diagnosis code is set.
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Q.
Is the diagnosis code set?
Replace the CVT-ECU or A/T-ECU.
The trouble can be an intermittent malfunction such as a poor connection or open circuit in the CAN bus lines between the CVT-ECU or A/T-ECU and the ETACS-ECU (GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction
).
STEP 5. 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)Check if diagnosis code is set.
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Q.
Is the diagnosis code set?
Replace the ETACS-ECU.
The trouble can be an intermittent malfunction such as a poor connection or open circuit in the CAN bus lines between the CVT-ECU or A/T-ECU and the ETACS-ECU (GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction
).