Code No. P1231: Trustful Check Active Stability Control (ASC) <Vehicles with ASC>
FUNCTION
Checks for an abnormal signal of ASC system via the CAN communication.
TROUBLE JUDGEMENT
Check Condition
Ignition switch is "ON" position.
Judgement Criterion
A torque demand signal from the ASC system is abnormal.
FAIL-SAFE AND BACKUP FUNCTION
Torque requested by ASC system is ignored.
PROBABLE CAUSES
Failed ASC system
Failed engine-ECU
DIAGNOSIS PROCEDURE
STEP 1. M.U.T.-III diagnosis code.
Reconfirmation of diagnosis code
Q. Is diagnosis code No. P1231 set?
Go to Step 2.
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions).
STEP 2. M.U.T.-III other system diagnosis code.
Confirm whether the diagnosis code is set in the ASC-ECU.
Q. Is diagnosis code set?
Perform troubleshooting of the ASC system (Refer to GROUP 35C - Troubleshooting, Diagnosis Code Chart
).
Replace the engine-ECU.