Code No. U1100:
Engine-ECU CAN Timeout
caution |
- If there is any
problem in the CAN bus lines, an incorrect diagnosis code may be set. Prior to this diagnosis,
diagnose the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics Table
).
- If diagnosis code U1100 is set in ASTC-ECU, always diagnose the CAN bus line. If
there is any fault in the CAN bus lines, an incorrect diagnosis code may be set. In this case,
the set diagnosis code is not highly reliable.
- Whenever ECU is replaced, ensure that the CAN bus lines are normal.
- When the hydraulic unit (integrated with ASTC-ECU) is replaced, always carry out
the calibration of the steering wheel sensor and the G and yaw rate sensor.
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OPERATION
The ASTC-ECU communicates with the engine-ECU via the CAN bus lines.
DIAGNOSIS CODE SET CONDITIONS
The ASTC-ECU receives the engine control system-related signals from the engine-ECU via
the CAN bus lines. When these signals cannot be received, the ECU sets this diagnosis code.
PROBABLE CAUSES
- The CAN bus line is defective.
- Malfunction of the engine-ECU
- Malfunction of the hydraulic unit assembly (integrated with ASTC-ECU)
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STEP 1. M.U.T.-III CAN bus diagnosis
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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 3.
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Repair the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics Table ).
On completion, go to Step 2.
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STEP 2. Diagnosis code recheck after resetting CAN bus lines
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Q.
Is diagnosis code No. U1100 set?
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Go to Step 3.
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This diagnosis is complete.
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STEP 3. Check for diagnosis codes of other systems.
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Check if the diagnosis code is set in the engine-ECU (Refer to GROUP 13A - Diagnosis
Code Chart) <4G64> or (Refer to GROUP 13B - Diagnosis Code Chart) <4D56>.
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Q.
Is the diagnosis code set?
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Troubleshoot the engine-ECU diagnosis code (Refer to GROUP 13A - Diagnosis
Code Chart) <4G64> or (Refer to GROUP 13B - Diagnosis Code Chart) <4D56>.
Then go to Step 6.
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Go to Step 4.
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STEP 4. Check for diagnosis codes of other systems.
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Check whether an engine "time-out" related diagnosis code is set in other ECUs.
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Q.
Is the diagnosis code set?
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Replace the engine-ECU (Refer to GROUP 13A - Engine-ECU) <4G64> or
(Refer to GROUP 13B - Engine-ECU) <4D56>. Then go to Step 6.
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Go to Step 5.
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STEP 5. Check whether the diagnosis code is set again.
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Check again if the diagnosis code is set.
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(1)Turn the ignition switch to the "LOCK" (OFF) position.
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(2)Turn the ignition switch to the "ON" position.
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(3)Erase the diagnosis code.
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(4)Turn the ignition switch to the "LOCK" (OFF) position.
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(5)Turn the ignition switch to the "ON" position.
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(6)Check if the diagnosis code is set.
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Q.
Is diagnosis code No. U1100 set?
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Replace the hydraulic unit assembly (integrated with ASTC-ECU). Then go to Step
6.
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The trouble can be an intermittent malfunction (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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Check again if the diagnosis code is set.
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(1)Turn the ignition switch to the "LOCK" (OFF) position.
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(2)Turn the ignition switch to the "ON" position.
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(3)Erase the diagnosis code.
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(4)Turn the ignition switch to the "LOCK" (OFF) position.
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(5)Turn the ignition switch to the "ON" position.
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(6)Check if the diagnosis code is set.
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Q.
Is diagnosis code No. U1100 set?
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Return to Step 1.
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The procedure is complete.
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