Code No.U1201: Yaw rate sensor (parity error)
Code No.U1202: G-sensor parity error


caution
  • If diagnosis codes No.U1201 and U1202 are 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
These diagnosis codes are set in the following cases:
Code No.U1201
  • The yaw rate signal output by G and yaw rate sensor is abnormal.
Code No.U1202
  • The longitudinal G signal output by G and yaw rate sensor is abnormal.

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.U1201 or U1202 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.U1201 or U1202 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.

Q. Is code No.U1201 or U1202 set?
Go to Step 1.
The procedure is complete.