Typical Enabling Conditions

Monitor runs whenever following DTCs not present



ECM RAM errors (P0604):

RAM mirror check


ECM CPU range check (P0606):

Either of following conditions met:


Difference between throttle valve position of main CPU and throttle valve position of sub CPU

0.3 V or more

Difference between accelerator pedal position of main CPU and accelerator pedal position of sub CPU

0.3 V or more

ECM CPU malfunction (P0607):

CPU reset


Electronic throttle control system power supply function of ECM malfunctions (P0657):

ETCS (Electronic Throttle Control System) power supply when ignition switch turned to ON

Read freeze frame data using an intelligent tester. Freeze frame data record the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data, from the time the malfunction occurred.

Do It Yourself Car Diagnosis

Do It Yourself Car Diagnosis

Don't pay hundreds of dollars to find out what is wrong with your car. This book is dedicated to helping the do it yourself home and independent technician understand and use OBD-II technology to diagnose and repair their own vehicles.

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