If there is
any problem in the CAN bus lines, an incorrect diagnosis code may be set. Prior to this diagnosis,
diagnose the CAN bus lines (Refer to GROUP 54C, Trouble code diagnosis ).
Whenever ECU is replaced, ensure that the CAN bus lines are normal.
OPERATION
ASC-ECU monitors if the output of G and yaw rate sensor is normal or not.
DIAGNOSIS CODE SET CONDITIONS
This diagnosis code is set when the abnormality is detected by comparing the longitudinal
G-sensor value output from the G and yaw rate sensor with the value output from the wheel speed
sensor.
PROBABLE CAUSES
Malfunction of wheel speed sensor
ASC-ECU malfunction
External noise interference
note
When rotated on the four-wheel drum tester, this diagnosis code may be set.
DIAGNOSIS PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnosis
Use M.U.T.-III to diagnose the CAN bus lines.
Q.
Is the check result normal?
Go to Step 3
Repair the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics Table ).
On completion, go to Step 2.
STEP 2. Diagnosis code recheck after resetting CAN bus lines
Q.
Is the diagnosis code No.C1242 set?
Go to Step 3
This diagnosis is complete.
STEP 3. Check the wheel speed sensor-related diagnosis code.
Use the M.U.T.-III to check whether the wheel speed sensor-related diagnosis code is set
or not.
Q.
Is the diagnosis code set?
Troubleshoot for the relevant diagnosis code (Refer to ).
Go to Step 4
STEP 4. Check whether the ASC-ECU is installed properly.
Check whether the ASC-ECU is installed correctly. Refer to .
Q.
Is the check result normal?
Execute "G sensor calibration" on "Special function". After the calibration is
performed (Refer to ) , turn the ignition switch from "OFF"
to "ON".Then go to Step 5.
Install the ASC-ECU properly, and execute "G sensor calibration" on "Special function".
After the calibration is performed (Refer to ) , turn the
ignition switch from "OFF" to "ON".Then go to Step 5.
STEP 5. M.U.T.-III data list
Check the following data list under curb weight condition or one occupant (driver) only
in the vehicle, on a flat road (Refer to ).
Item 09: G sensor
Item 96: G sensor offset
Q.
Is the check result normal?
Turn the ignition switch to the "ON" from "OFF" position. Then go to Step 6.
Replace the hydraulic unit (integrated with ASC-ECU) (Refer to ),
and then go to Step 7.
STEP 6. Check whether the diagnosis code is reset.
(1)Erase the diagnosis code.
(2)Drive the vehicle at 20 km/h or higher.
note
The ABS warning lamp does not turn OFF in some cases unless the vehicle runs at 20 km/h
or higher.
Q.
Is the diagnosis code No.C1242 set?
Replace the hydraulic unit (integrated with ASC-ECU) (Refer to ),
and then go to Step 7.
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/How
to Cope with Intermittent Malfunctions ).
STEP 7. Check whether the diagnosis code is reset.
(1)Erase the diagnosis code.
(2)Drive the vehicle at 20 km/h or higher.
note
The ABS warning lamp does not turn OFF in some cases unless the vehicle runs at 20 km/h
or higher.
Go to Step 3
Repair the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics Table 
).
On completion, go to Step 2.