Code No.U1205: G and yaw rate sensor message counter error
caution
If diagnosis code No.U1205 is set in the ASTC-ECU, always diagnose the CAN main bus line. If there is any fault in the CAN bus lines, an incorrect diagnosis code may be set.
Whenever the ECU is replaced, ensure that the communication circuit is normal.
OPERATION
ASTC-ECU receives the longitudinal and lateral G detected by the G and yaw rate sensor via the CAN bus line.
DIAGNOSIS CODE SET CONDITION
This diagnosis code is set when the ASTC-ECU power supply voltage is normal but the signal sent from the G and yaw rate sensor differs from the signal sent at the previous time by more than the specified value.
PROBABLE CAUSES
Noise generated in the CAN bus line
Damaged harness or connector.
Malfunction of the G and yaw rate sensor.
Malfunction of the ASTC-ECU.
DIAGNOSIS PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics
Use M.U.T.-III to diagnose the CAN bus lines.
Q.
Is the check result normal?
Go to Step 2.
Repair the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics Table ). Then go to Step 4.
STEP 2. M.U.T.-III diagnosis code
(1)Turn the ignition switch to the "ON" position.
(2)Erase the diagnosis code.
(3)Turn the ignition switch to the "LOCK" (OFF) position.
(4)Turn the ignition switch to the "ON" position.
(5)Check if the diagnosis code is set.
(6)Turn the ignition switch to the "LOCK" (OFF) position.
Q.
Is code No.U1205 set?
Replace the G and yaw rate sensor (Refer to ). Then go to Step 3.
Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).
STEP 3. M.U.T.-III diagnosis code
(1)Turn the ignition switch to the "ON" position.
(2)Erase the diagnosis code.
(3)Turn the ignition switch to the "LOCK" (OFF) position.
(4)Turn the ignition switch to the "ON" position.
(5)Check if the diagnosis code is set.
(6)Turn the ignition switch to the "LOCK" (OFF) position.
Q.
Is code No.U1205 set?
Replace the hydraulic unit (integrated with ASTC-ECU) (Refer to ). Then go to Step 4.
The procedure is complete.
STEP 4. Check whether the diagnosis code is reset.
(1)Turn the ignition switch to the "ON" position.
(2)Erase the diagnosis code.
(3)Turn the ignition switch to the "LOCK" (OFF) position.
(4)Turn the ignition switch to the "ON" position.
(5)Check if the diagnosis code is set.
(6)Turn the ignition switch to the "LOCK" (OFF) position.
Go to Step 2.
Repair the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics Table 
). Then go to Step 4.