Code No.U1102,
U1103: ABS-ECU or TCL/ASC-ECU time-out
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- If diagnosis
code No.U1102, U1103 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
The ETACS-ECU receives parking brake-related signals from the ABS-ECU or the TCL/ASC-ECU
via the CAN bus lines. If the ABS-ECU or the TCL/ASC-ECU cannot receive the parking brake-related
signal at all, diagnosis code No.U1102 will be set. Also, if the ABS-ECU or TCL/ASC-ECU
cannot receive the ESS-related signal, the diagnosis code No. U1103 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
ABS-ECU or the TCL/ASC-ECU, the power supply system to the ABS-ECU or the TCL/ASC-ECU,
or the ETACS-ECU itself may be defective.
The M.U.T.-III shows a diagnosis code status as stored.
- If diagnosis code No.U1102, U1103 is stored as a past trouble, carry out diagnosis
with particular emphasis on wiring and connector(s) in the CAN bus line between the ETACS-ECU
and the ABS-ECU or the TCL/ASC-ECU, and the power supply system to the ABS-ECU or the
TCL/ASC-ECU. 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 ABS-ECU or the TCL/ASC-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 ). On
completion, go to Step 6.
STEP 2. Check the diagnosis code of the ABS-ECU or the TCL/ASC-ECU.
Check if the diagnosis code is set in either of the ABS-ECU or the TCL/ASC-ECU.
Q.
Is the diagnosis code set?
Diagnose the ABS-ECU or the TCL/ASC-ECU. Refer to GROUP 35B - Troubleshooting <ABS-ECU> or
GROUP 35C - Troubleshooting <TCL/ASC-ECU>.
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.
- Engine-ECU <M/T> or engine-A-M/T-ECU <Automated
manual transmission>
U1102: ABS or TCL/ASC-ECU time-out
- Combination meter
U1102: ABS or TCL/ASC-ECU time-out
- Electric power steering-ECU
U1102: ABS or TCL/ASC-ECU time-out
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?
The diagnosis code is not set. : A poor connection, open circuit or other intermittent malfunction is present in
the CAN bus lines between the ABS-ECU or the TCL/ASC-ECU and the ETACS-ECU (Refer to GROUP
00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent
Malfunctions ).
The diagnosis code is set <Vehicles without active stability control system>.
: Replace the ABS-ECU, and then go to Step 6.
The diagnosis code is set <Vehicles with active stability control system>. : Replace the TCL/ASC-ECU. Then perform the variant coding (Refer to GROUP
00 - Precautions Before Service - How to Perform Variant Coding ).
After variant coding, go to Step 6.
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 ABS-ECU or the TCL/ASC-ECU 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.