Code No.U1102: ABS-ECU or TCL/ASC-ECU CAN communication time-out
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- If diagnosis code No.U1102 is set in the meter-ECU, diagnose the CAN bus lines.
- Whenever the ECU is replaced, ensure that the communication circuit is normal.
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TROUBLE JUDGMENT
The combination meter receives signal from the ABS-ECU or the active stability control-ECU via CAN bus lines. If it does not receive any signals from the ABS-ECU or the TCL/ASC-ECU, diagnosis code No.U1102 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 ABS-ECU or TCL/ASC-ECU and the combination meter, the power supply system to the ABS-ECU, the ABS-ECU or TCL/ASC-ECU 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 ABS-ECU or the TCL/ASC-ECU and the combination meter, and the power supply system to the ABS-ECU or the TCL/ASC-ECU. For diagnosis procedures, refer to "How to treat past trouble" (Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points
).
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For a past trouble, you can 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 Malfunction 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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| 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 the ABS-ECU or the TCL/ASC-ECU
- Malfunction of the combination meter
DIAGNOSIS PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics
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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 normal?
Go to Step 2.
Repair the CAN bus line (Refer to GROUP 54C, Troubleshooting ). Repair the CAN bus line and go to Step 6.
STEP 2. M.U.T.-III other system diagnosis code
Check that the ABS-ECU or TCL/ASC-ECU sets a diagnosis code.
Q.
Is the diagnosis code set?
Diagnose the ABS and the TCL/ASC systems. Refer to GROUP 35B, Troubleshooting or GROUP 35C, Troubleshooting . 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.
MPI
- Code No.U1102: ABS-ECU or TCL/ASC-ECU time-out diagnosis code
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 from "LOCK" (OFF) position 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 ABS-ECU or the TCL/ASC-ECU 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 combination meter and the ABS-ECU or TCL/ASC-ECU (Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).
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 from "LOCK" (OFF) position 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 ). 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 combination meter and the ABS-ECU or the TCL/ASC-ECU (Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).
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)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.