If diagnosis
code No. U1000 is set, be sure to diagnose the CAN bus line.
When replacing the CAN box unit, always check that the communication circuit is
normal.
DIAGNOSTIC FUNCTION
If the signal from OSS-ECU cannot be received, the CAN box unit sets the diagnosis code
No. U0230.
JUDGEMENT CRITERIA
With the statuses that the ignition switch is at ON position, system voltage is 10 - 16
V (data from ETACS-ECU), and there is no malfunction to the power supply fuse (IOD fuse), or odometer
value is 80.5 km or more, if the communication with OSS-ECU cannot be established for 2,500
ms or more, the CAN box unit determines that a problem has occurred.
PROBABLE CAUSES
Malfunction of CAN bus line
Malfunction of OSS-ECU
Malfunction of CAN box unit
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 ).
STEP 2. M.U.T.-III other system diagnosis code
Check again if the diagnosis code is set to the OSS-ECU.
Q.
Is the diagnosis code set?
Troubleshoot the OSS-ECU (Refer to GROUP 42B - Diagnosis Code Chart ),
and then go to Step 3.
Go to Step 3.
STEP 3. Check the M.U.T.-III Diagnosis code for other systems
Check if the diagnosis code No. U1000 is set to ETACS-ECU.
Q.
Is the diagnosis code set?
Go to Step 4
Go to Step 5
STEP 4. Diagnosis code recheck
Check again if the diagnosis code is set to the CAN box unit.
(1)Erase the diagnosis code.
(2)Turn the ignition switch from the "LOCK" (OFF) position to the "ON" position.
(3)Check if the diagnosis code is set.
Q.
Is the diagnosis code set?
Replace the OSS-ECU. (Refer to GROUP 42B - OSS-ECU .)
A poor connection, open circuit or other intermittent malfunction in the CAN bus
line between the CAN box unit and the OSS-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.
Check again if the diagnosis code is set to the CAN box unit.
(1)Erase the diagnosis code.
(2)Turn the ignition switch from the "LOCK" (OFF) position to the "ON" position.
(3)Check if diagnosis code is set.
Q.
Is the diagnosis code set?
Replace the CAN box unit.
A poor connection, open circuit or other intermittent malfunction in the CAN bus
line between the CAN box unit and the OSS-ECU. (Refer to GROUP 00 - How to Use Troubleshooting/Inspection
Service Points - How to Cope with Intermittent Malfunction .)