Code No. U1100: Engine-ECU or engine-A-M/T-ECU time-out (related to engine)
Code No. U1101: Engine-A-M/T-ECU time-out (related to automated manual transmission)
| caution |
- If diagnosis code No.U1100 or U1101 is set in the meter, diagnose the CAN bus lines.
- Whenever the ECU is replaced, ensure that the communication circuit is normal.
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TROUBLE JUDGMENT
U1100
- The combination meter receives engine control system-related signals from the engine-ECU <M/T> or engine-A-M/T-ECU <Automated manual transmission> via CAN bus lines. If the combination meter cannot receives the necessary signals, diagnosis code No. U1100 will be set.
U1101
- The combination meter receives transmission control system-related signal from the engine-ECU <M/T> or engine-A-M/T-ECU <Automated manual transmission> via CAN bus lines. If the combination meter cannot receive the necessary signals, diagnosis code No. U1101 will be set.
COMMENTS 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 engine-ECU <M/T> or engine-A-M/T-ECU <Automated manual transmission> and the combination meter, the power supply system to the engine-ECU <M/T> or engine-A-M/T-ECU <Automated manual transmission>, the engine-ECU <M/T> or engine-A-M/T-ECU <Automated manual transmission> itself, or the combination meter may be defective.
The M.U.T.-III shows a diagnosis code status as stored.
- Carry out diagnosis with particular emphasis on connector(s) or wiring harness in the CAN bus lines between the engine-ECU <M/T> or engine-A-M/T-ECU <Automated manual transmission> and the combination meter, and the power supply system to the engine-ECU <M/T> or engine-A-M/T-ECU <Automated manual transmission>. For diagnosis procedures, refer to "How to cope with past trouble" (Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points
).
| note |
For a past trouble, you may 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 Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ). 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 Diagnostics Table ).
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| caution |
If the ignition switch is turned on without starting the engine and then one minutes passes, the combination meter may store U1100, U1101, U1102, U1106, U1109 and U1112 as past trouble.
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PROBABLE CAUSES
- Damaged harness wires and connectors
- Malfunction of engine-ECU <M/T> or engine-A-M/T-ECU <Automated manual transmission>
- Malfunction of combination meter
DIAGNOSIS PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics
| warning |
Since the radiator fan rotates during CAN bus line diagnostics, make sure that no one is servicing the engine compartment before diagnosing the CAN bus line. Since the CAN communication stops when diagnosing the CAN bus line, the ETACS-ECU detects the time-out of the engine-ECU, and activates the radiator fan to prevent overheating as fail-safe.
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Use the M.U.T.-III to diagnose the CAN bus lines.
Q.
Is the check result satisfactory?
Go to Step 2.
Repair the CAN bus lines (Refer to 54C, Troubleshooting ). Repair the CAN bus line and go to Step 6.
STEP 2. M.U.T.-III other system diagnosis code
Check whether the MPI system system-related diagnosis code is set.
Q.
Is the diagnosis code set?
Diagnose the MPI system. 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.
ABC-ECU
- Code No. U1100: engine-ECU or engine-A-M/T-ECU time-out (related to Engine)
ETACS-ECU
- Code No. U1100: engine-ECU or engine-A-M/T-ECU time-out (related to Engine)
A/C-ECU
- Code No. U1100: engine-ECU or engine-A-M/T-ECU time-out (related to Engine)
Q.
Is the diagnosis code set?
Go to Step 4.
Go to Step 5.
STEP 4. 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 to "ON" position.
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(3)Check if the diagnosis code is set.
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Q.
Is the diagnosis code set?
After the engine-ECU <M/T> or the engine-A-M/T-ECU <Automated manual transmission> is replaced, then perform the variant coding and write the VIN data (Refer to GROUP 00, Precautions Before Service - How to Perform Variant Coding ). Then 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 engine-A-M/T-ECU <Automated manual transmission> and the combination meter (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.
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(1)Erase the diagnosis code.
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(2)Turn the ignition switch to "ON" position.
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(3)Check if the diagnosis code is set.
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Q.
Is the diagnosis code set?
After the combination meter is replaced, then perform the variant coding (Refer to GROUP 00, Precautions Before Service - How to Perform Variant Coding ). Then 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 engine-A-M/T-ECU <Automated manual transmission> and the combination meter (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 to "ON" position.
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(3)Check if the diagnosis code is set.
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Q.
Is the diagnosis code set?
Return to Step 1.
The procedure is complete.