Is this the Accelerator (Throttle) Pedal (position) sensor?

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Jul 14, 2020
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South of Metro Atlanta
I have a 2015 Lexus RX350, 206k miles, has been well taken care of, in great shape. Most of that 206k miles is highway/commuter miles.

Anyway, For several months, I have noticed a surge or jump in RPMs (both on the tach and sound / feel of the engine), primarily when in Park and I press the throttle. I try to hold it at 2000 RPMs and the tach will bounce some or rev more as I diligently try to hold the pedal still. It is less prominent at 3000 RPMs, etc.

I feel it when moving and getting back in the accelerator after a turn, etc. I can feel some 'jump' but it's dampened because the car is moving/etc.

No, I haven't hooked my code reader up to it lately, I meant to grab it this morning and hook it up and let it run while driving to work. I'll do it tonight or tomorrow.

No check engine light is present.



Help!
 
Hook up your scanner since you have one. The TPS should read out in % so see if it's value is bouncing around when it's being held steady. When it gets out of spec 'enough', it should throw a code but it might be an ABS code. No ABS light on, I presume ?
 
Highly unlikely that your APP sensor is bad. I have NEVER replaced a throttle pedal on a Toyota product in all my years. Being a completely digital system, there are built in fail-safe procedures within the ECM to prevent accidental acceleration or the like. Should your pedal actually become sketchy, the ECM would immediately pick up on it due to redundancy.

I second the previous recommendation of a TB clean and a battery disconnect/ECM reset.
 
Ok, just wanted to follow up.

1. I never hooked my code reader up. Just never got around to it.

2. I cleaned the throttle body on Saturday. WOWOWOWOWOWOW. Again, this is a Toyota 2GR-FE engine, in an RX350, typical obstacles in the way. I removed the wipers, wiper motor, cowl and air intake/filter box. This allowed me to remove the throttle body (I kept the coolant lines connected) and have much better access and sight to the internals.

I did as most videos show - I sprayed some paper towels with intake/throttle body cleaner (I had a can of CRC) and wiped/soaked the effected areas (plate, cylinder, rod/etc). I even took an old toothbrush and sprayed/soaked it to scrub the areas around the rod and inside the cylinder walls. I even soaked another couple of paper towels and just let them sit while the plate kept pressure on them.

Then I wiped everything clean with clean paper towels and finally with a clean microfiber towel. I then soaked some more paper towels and cleaned inside the plenum area behind the throttle body (doesn't really matter, the build up in this area doesn't affect throttle performance/etc., but I said "might as well".

Buttoned everything back up (got down to the LAST nut on the last bolt - at the driver's side wiper, and almost boogered the threads up, took me a while to get the nut started and tightened) and re-started the engine.

RPMs ran right to 2000 just like many had said, but calmed down after a few minutes.

Took it on a test drive and immediately felt the difference in throttle. I know it's not the case, but it seems like it's got an extra 100 hp. Throttle response is much quicker/touchy and I didn't think it was bad to start with.

I am sure this had never been done in the 206k miles it's lived. I'm itching to do my other two vehicles now, both Toyota 5.7L engines, will be much, much easier/simpler.
 
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