If the diagnosis
code No. U0100 is set, be sure to diagnose the CAN bus line.
When replacing the ECU, always check that the communication circuit is normal.
DIAGNOSTIC FUNCTION
The combination meter sets diagnosis code No.U0100 when it cannot receive signals from
the engine ECU.
JUDGMENT 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, or odometer value
is 80.5 km or more, if the communication with engine ECU cannot be established for 600 ms or
more, the combination meter determines that a problem has occurred.
PROBABLE CAUSES
Malfunction of CAN bus line
Malfunction of engine ECU
Malfunction of combination meter
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 if diagnosis code is set to the engine-ECU.
Q.
Is the diagnosis code set?
Troubleshoot the engine (Refer to GROUP 13A - Diagnosis Code Chart ).
Go to Step 3.
STEP 3. Check whether the diagnosis code is reset.
Check again if the diagnosis code is set to the combination meter.
(1)Erase the diagnosis code.
(2)Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
(3)Check if diagnosis code is set.
Q.
Is the diagnosis code set?
Replace the combination meter.
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How
to use Troubleshooting/inspection Service Points - How to Cope with Intermittent
Malfunction ).
Repair the CAN bus line (Refer to GROUP 54C - Troubleshooting 
).