Trouble Judgment

Check Conditions 

• The power supply circuit system DTC C1540, C1541 is not set.
• The engine circuit system DTC is not set.

Judgment Criterion 

• Abnormal engine speed signal sent to the electric power steering-ECU is received once or more.
• The abnormal engine speed signal is sent from the engine control module (ECM), and the microcomputer determines that there is a problem in the engine speed measurement system.

Fail Safe, Back Up Function 

• The electric power steering-ECU illuminates the electric power steering warning display, and sets the DTC U0401. Normally the assist operation is continued while the vehicle is driven, but deactivated after the vehicle stopped.