Hi everyone. Recently bought a IS350 (RWD auto) in May (128000 km) with a full Lexus service history and it's brilliant except for one thing:

When I press very lightly on the accelerator pedal I get no response. It's as if the first 3 mm of pedal does nothing. I have hooked up an OBDII scanner and it is showing the APP sensor values change for the first 3 mm of movement, but there is no change to the commanded throttle actuator value. It seems like the ECU ignores very small throttle input.

I have also found that it is difficult to start smoothly in 1st gear. If I put the car in snow mode it starts in 2nd and is very smooth, but in 1st gear when I apply low amounts of throttle the revs spike up from 600 rpm to 1000 rpm. The car jerks forward and back and then starts to move.

Has anyone experienced similar problems?

Happy to share videos OBDII data if necessary. Thank you.

 

Sounds like the APPS is starting to go. I would seriously recommend getting a new one. Once this thing goes out. You will lose all throttle control. The car will just stall out with no throttle what so ever.

If you look at the 2nd Gen GS models they are notorious on this issue. I first experienced this with my old GS400. It's not a good thing trying to cross a busy intersection, and almost get T Boned.

 

When was the ECU reset last? Mine has over 40,xxx mi since last reset.

Or turn ignition on, engine not running and depress the pedal to the floor smoothly and evenly down and up like 5x and turn the key off.

Try that before ECU reset...

 

Since you have purchased the car, has the battery been disconnect for at least 20 minutes for any reason? If not, I recommend doing this to reset the vehicle to help it learn YOUR driving style.

 

I have done multiple ECU resets to no effect. So the Accelerator Pedal Position D (%) sensor rests at 16.1% and the throttle does not move until the value reaches 19.4%. Between 16.1% and 19.4% I am pressing the pedal further and nothing is happening.

 

Were these reading taken in "normal" mode? If so, try "POWER" mode, and see what if any changes take place.

 

In power mode the throttle begins to move at 18.4% of APP sensor output.