Code No.U1100: Engine-ECU <M/T> or engine-A-M/T-ECU <automated manual transmission> time-out (related to engine)/No.U1101: Engine-A-M/T-ECU time-out (related to automated manual transmission)
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- If diagnosis code No.U1100 or U1101 is set in the ETACS, diagnose the CAN main bus line.
- Whenever the ECU is replaced, ensure that the communication circuit is normal.
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TROUBLE JUDGMENT
Diagnosis code No.U1100
- The ETACS-ECU receives engine control system-related signals from the engine-ECU <M/T> or the engine-A-M/T-ECU <Automated manual transmission> through the CAN bus lines. If the engine-ECU <M/T> or the engine-A-M/T-ECU <Automated manual transmission> cannot receive the engine control system-related signal at all, diagnosis code No.U1100 will be set.
Diagnosis code No.U1101
- The ETACS-ECU receives the transmission control signals from the engine-A-M/T-ECU <Automated manual transmission> via CAN bus lines. If the engine-A-M/T-ECU <Automated manual transmission> cannot receive the transmission control signal at all, diagnosis code No.U1101 will be set.
COMMENT ON TROUBLE SYMPTOM
The M.U.T.-III shows a diagnosis code status as active.
- Connector(s) or wiring harness in the CAN bus lines between the ETACS-ECU and the engine-ECU <M/T> or the engine-A-M/T-ECU <Automated manual transmission>, the power supply circuits to the engine-ECU <M/T> or the engine-A-M/T-ECU <Automated manual transmission>, or the ETACS-ECU itself may be defective.
The M.U.T.-III shows a diagnosis code status as stored.
- If diagnosis code No.U1100 or U1101 is set as past trouble, carry out diagnosis with particular emphasis on wiring and connector(s) in the CAN bus lines between the ETACS-ECU and the engine-ECU <M/T> or the engine-A-M/T-ECU <Automated manual transmission>, or power supply to the engine-ECU <M/T> or the engine-A-M/T-ECU <Automated manual transmission>. For diagnosis procedures, refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Treat Past Trouble
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For a past trouble, you cannot 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 Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions and check the CAN bus lines. You can narrow down the probable 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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PROBABLE CAUSES
- Malfunction of the engine-ECU <M/T> or the engine-A-M/T-ECU <Automated manual transmission>
- 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 6.
STEP 2. Check the diagnosis code of the engine-ECU <M/T> or the engine-A-M/T-ECU <Automated manual transmission>.
Check if the diagnosis code is set in either of the engine-ECU <M/T> or the engine-A-M/T-ECU <Automated manual transmission>.
Q.
Is the diagnosis code set?
Diagnose the engine-ECU or the engine-A-M/T-ECU (Refer to GROUP 13A, Troubleshooting <1100>, GROUP 13B, Troubleshooting <1300, except 1500-T/C> or GROUP 13C, Troubleshooting <1500-T/C>). And then go to Step 3.
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.
- ABS-ECU <vehicles without TCL/ASC> or TCL/ASC-ECU <vehicles with TCL/ASC>
U1100: Engine-ECU <M/T> or engine-A-M/T-ECU <Automated manual transmission> time-out (related to engine)
- Combination meter
U1101: Engine-A-M/T-ECU time-out (related to automated manual transmission)
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.
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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 engine-ECU <M/T> or the engine-A-M/T-ECU <Automated manual transmission>.Then perform the variant coding (Refer to GROUP 00 - Precautions Before Service - How to Perform Variant Coding ). After variant coding, go to Step 6.
A poor connection, open circuit or other intermittent malfunction is present in the CAN bus lines between the engine-ECU <M/T> or the engine-A-M/T-ECU <Automated manual transmission> 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.
Check again if the diagnosis code is set.
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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. Then perform the variant coding and write the VIN data (Refer to GROUP 00, Precautions Before Service - How to Perform Variant Coding ). After variant coding, go to Step 6.
A poor connection, open circuit or other intermittent malfunction is present in the CAN bus lines between the engine-ECU <M/T> or the engine-A-M/T-ECU <Automated manual transmission> and the ETACS-ECU (Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).
STEP 6. Check whether the diagnosis code is reset.
Recheck if the diagnosis code is set.
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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?
Return to Step 1.
The procedure is complete.