Code No.U1112:
SRS-ECU time-out
| caution |
- If diagnosis
code No.U1112 is set in the ETACS, diagnose the CAN main bus line.
- Whenever the ECU is replaced, ensure that the communication circuit is normal.
|
TROUBLE JUDGMENT
The ETACS-ECU receives SRS-related signal from the SRS-ECU via the CAN bus lines. If the
SRS-ECU cannot receive the SRS-related signal at all, diagnosis code No.U1112 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
SRS-ECU, the power supply system to the SRS-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.U1112 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 SRS-ECU, and the power supply system to the SRS-ECU. For diagnosis procedures, refer to
GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Treat
Past Trouble
.
| note |
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 ).
|
PROBABLE CAUSES
- Malfunction of the SRS-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 SRS-ECU
Check that an SRS-ECU diagnosis code is set.
Q.
Is the diagnosis code set?
Diagnose the SRS-ECU. Refer to GROUP 52B - Troubleshooting <COLT>
or <COLT CZ3>. 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>
U1112: SRS-ECU time-out
- Combination meter
U1112: SRS-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.
|
|
(1)Erase the diagnosis code.
|
|
|
(2)Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
|
|
|
(3)On completion, check that the diagnosis code is not reset.
|
Q.
Is the diagnosis code set?
Replace the SRS-ECU, and then go to Step 6.
A poor connection, open circuit or other intermittent malfunction is present in
the CAN bus lines between the SRS-ECU 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.
|
|
(1)Erase the diagnosis code.
|
|
|
(2)Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
|
|
|
(3)On completion, check that the diagnosis code is not reset.
|
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 SRS-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.
|
|
(1)Erase the diagnosis code.
|
|
|
(2)Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
|
|
|
(3)On completion, check that the diagnosis code is not reset.
|
Q.
Is the diagnosis code set?
Return to Step 1.
The procedure is complete.