Code No.C1388: Yaw rate sensor (active check error)
Code No.C1389: G-sensor (active check error)


caution If there is any problem in the CAN bus lines, an incorrect diagnosis code may be set. Diagnose the CAN bus lines before the diagnosis codes (Refer to GROUP 54C - CAN Bus Diagnostics Table ).

OPERATION
The G and yaw rate sensor detects longitudinal, lateral, and yaw rate G for the vehicle, and sends them to ASTC-ECU via the CAN bus line.

DIAGNOSIS CODE SET CONDITION
These diagnosis codes are set when the power supply voltage of ASTC-ECU is normal but the G and yaw rate sensor operates abnormally.

PROBABLE CAUSES
The most likely causes for these diagnosis codes to set are:

  • Malfunction of G and yaw rate sensor
  • Damaged wiring harness or connector
  • Malfunction of the hydraulic unit assembly (integrated with 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 line (Refer to GROUP 54C - CAN Bus Diagnostics Table ). Then go to Step 2.

STEP 2. 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.C1388 or C1389 set?
Replace the G and yaw rate sensor (Refer to ). Then go to Step 3.
The procedure is complete.

STEP 3. 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.C1388 or C1389 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.C1388 or C1389 set?
Go to Step 1.
The procedure is complete.