The ETACS-ECU receives the vehicle speed signal from the engine-ECU via the CAN bus line.
When the received vehicle speed signal contains the failure information, the diagnosis code
No. U1150 is stored.
PROBABLE CAUSES
Malfunction of the vehicle speed sensor
Malfunction of the engine-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 5.
STEP 2. Check the diagnosis code of the engine-ECU.
Check that the engine-ECU set a diagnosis code.
Q.
Is the diagnosis code set?
Diagnose the engine-ECU. Refer to GROUP 13A -
Troubleshooting .
On completion, go to Step 5.
Go to Step 3.
STEP 3. 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)On completion, check that the diagnosis code is reset.
Q.
Is the check result normal?
A poor connection, open circuit or other intermittent malfunction is present in
the CAN bus lines between the engine-ECU and the ETACS-ECU (Refer to GROUP 00, How to Use Troubleshooting/Inspection
Service Points -
How to Cope with Intermittent Malfunctions ).
Replace the engine-ECU. After replacing the ECU, carry out the CAN bus diagnostics.
Then go to Step 4.
STEP 4. 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)On completion, check that the diagnosis code is not reset.
Q.
Is the check result normal?
The procedure is complete.
Replace the ETACS-ECU. After replacing the ECU, carry out the CAN bus diagnostics.
Then go to Step 5.
STEP 5. Check whether the diagnosis code is reset.
Recheck 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)On completion, check that the diagnosis code is reset.
Repair the CAN bus line (Refer to GROUP 54C -
Troubleshooting 
).
On completion, go to Step 5.