Before replacing the ECU,
ensure that the input and output signal circuits are normal.
COMMENTS ON TROUBLE SYMPTOM
Current trouble
If the roof lid glass position is out of the specified area, ETACS-ECU sets the
diagnosis code No. L0637.
Past trouble
If the diagnosis code No. L0637 is set as past trouble, carry out diagnosis with
particular emphasis on wiring and connector(s) in the CAM bus communication line. For diagnosis
procedures, refer to How to treat past trouble (Refer to GROUP 00 -
How to Use Troubleshooting/Inspection
Service Points ).
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 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 Line Diagnostic Flow ).
PROBABLE CAUSES
Malfunction of the sunroof motor assembly
DIAGNOSTIC PROCEDURE
STEP 1. Check the sunroof fully closed position
(1)Carry out the learning procedures of the sunroof fully closed position. Refer to .
(2)Recheck if the diagnosis code is set.
.....
Erase the diagnosis code.
.....
Turn the ignition switch from the LOCK (OFF) position to the ON position.
.....
Check if the diagnosis code is set.
Q.
Is the check result normal?
The diagnosis is complete.
Go to Step 2.
STEP 2. Diagnosis code recheck
Recheck if the diagnosis code is set.
(1)Erase the diagnosis code.
(2)Turn the ignition switch from the LOCK (OFF) position to the ON position.
).
The diagnosis is complete.