Code No.U1120 Bus
line (CAN-C) low input
Code No.U1121 Bus line (CAN-C) high input
JUDGMENT CRITERIA
When the CAN bus line voltage is in the following states, the ETACS-ECU set the diagnosis
code.
- If the CAN bus line voltage is 0.3 V or less, the diagnosis code No. U1120
is set.
- If the CAN bus line voltage is 4.7 V or more, the diagnosis code No. U1121 is set.
PROBABLE CAUSES
- Malfunction of CAN bus line
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. Check whether the diagnosis code is reset.
Check again if the diagnosis code is set to the ETACS-ECU.
|
|
(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 ETACS-ECU.
The diagnosis is complete.