Does your vehicle experience SUA?

If YOU own a Toyota and experience SUA, please consider the following.   Switch to neutral, come to a complete stop by the side of the road, and then if you have the right frame of mind AND you are in a SAFE location, please do NOT switch off the engine.   Under SUA conditions, the engine is expected to be revving at high RPM (or perhaps going up and down) even if the gas pedal is not being pressed.  Take pictures of the dashboard with your cellphone, make a video clip if your phone supports camcorder operations, ask other people to verify the situation,  get a police officer to note the condition, and request their identities so that they can be witnesses to the occurrence.   A nearby friendly mechanic with an OBD-II device can be asked to read the following information:  read accelerator pedal data, the throttle position data and vehicle speed information.   Ask the mechanic to store/record the data.  Take a printout or make copious notes of the data (I would love a copy!).    Or, if you are in the Pittsburgh region, give us a call (you can find my coordinates by searching “Rajkumar CMU” in your favorite search engine) and we would like to take some readings while the engine is in that abnormal state.    Even if a dealer recommends turning off the engine to read stored Diagnostic Trouble Code (DTCs), please say no and ask them to read the accelerator/throttle position data BEFORE the engine is shut down.   DTCs are not stored under SUA conditions!  The end-result is that the dealer will very likely say “There is no problem with the vehicle!”.

The rationale is that if the engine is shut off and then restarted, the problem seems to go away (but may reappear later).  Diagnosing the situation is significantly easier when data are collected while in that abnormal state.  Again, the key is to get these data while the engine is still in the SUA state (albeit in neutral gear).

Alternatively, if you want to run some tests on your car after it has experienced SUA, please consider lending us your Toyota for a couple of weeks.    We are currently testing a Lexus IS250 in this mode.   Many Toyota vehicles do not encounter SUA, but some do.   Tests are expected to be much more likely to find a problem source by looking at the latter category of vehicles.

Please be safe under all cases.   If you know of somebody encountering SUA issues, please let them know of this as well.


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