1heckinboi

Hey everyone, I picked up a 2013 GS350 F Sport this monday and it’s been great since then. Had an issue this morning while leaving my house however, I stepped on the gas from my driveway and had no response from the gas or car. It seemed like the car went to neutral (was in drive) and just idled normally, I pressed on the gas all the way and it did not rev or shift. It did pick back up after I fully let off the pedal and step back on it, it seemed to repeat this issue from every stop and a few times on the highway it would try to go into a neutral state.

During the highway trip the cruise control would not activate or hold speed either, there’s no Check engine lights and it was not shifting harsh prior.

Knucklebus

Ah, the cruise might be the key piece of information. Generally, the cruise is kicked off by the brake light switch. Not on a Lexus GS but on another car, I had an issue with the cruise. It turned out to be the brake light switch. The part that kicked the cruise off was faulty-open instead of normally closed. The brakes light were not on and worked properly. Replacing it cured the problem.

So, I would check the brake light switch first. I do not know this to be true but I would imagine a throttle by wire would not allow throttle while the brake is registered as on.

jgscott

iTrader: (1)

How many miles on your car 1h? When you say seemed to go into neutral do you mean it just sits and revs, when you hit the gas, like you are pressing the accelerator and revving in park sitting still?

So also depending on what's wrong, I would be cautious pressing to floor in case it just caught and took off. Or are you saying the engine is not revving either?

1heckinboi

I’ll definitely take a look into it, I did another drive and I didn’t have any issues. Just a short 7 minute drive though.

The car is just over 60k miles. When I say in neutral I really mean it’s just at normal idle as if I was in park sitting. That was happening after I moved a little from a complete stop, as if the car didn’t know what to do and didn’t go into gear. The revs just drop to idle.

The car does not rev no matter the throttle position, 25%-100% it did not move from idle

jgscott

iTrader: (1)

Sounds like a drive by wire Throttle position sensor or something in that system that inputs your pedal to the Throttle body. ,Its reads current to control.

703

Looks like the previous owner offloaded the car for that reason. Can you take it back to the dealer? Obviously not safe with a pedal that doesn’t respond 100% of the time.

Throttle position sensors are very reliable and have fail safes. So I don’t think it’s the position sensor.

jgscott

iTrader: (1)

There been Lexus that were affected with this. There was a Lexus warranty extension on some. IDK, I could be wrong but it does link electronically the Pedal to the throttle body and other to the engine.
Post # 4
https://www.clublexus.com/forums/gs-...lfunction.html

Isn't this is what some are saying a Pedal Commander can mess up long term? Wonder if there any pending codes that were cleared or history?

1heckinboi

Think I may have something to follow, this morning I had only one instance of it happening, it did not happen anymore yesterday either.

I noticed that my rear brake lights were flickering(as if I were repeatedly stepping on the brakes) a little bit on stops, and while I was driving on the highway when I pressed slightly on the brakes to slow down I took my foot off the brake and noticed my lights were still on, I kind of used my sole to pull the pedal towards me to see if there was play or anything and the lights came off doing so. It was a dark morning so I could see my lights fairly well. I’m going to check if I can adjust the brake pedal at all and see if that helps with anything, I don’t know if it’s actually related to the acceleration issue but at least I can rule this out

Knucklebus

Most brake switches have some adjustment to them.

cnc369

it's possibly your pedal sensor is going out. it should throw a code but i've seen it not throw codes on mercedes benz and on infiniti as the ecm did not catch the issue to code. it's an easily replaceable part

chinee

My Sequoia had an Accelerator Pedal Position Sensor and a Throttle Position sensor, can't remember which failed but the car went into limp mode with no response from the pedal. Engine speed just stayed constant at about 1300 rpm.
Similar issue on my Infiniti G35, there are 2 crankshaft position sensor, failure causes the same limp mode.

But with your brake light issue... sounds like Mr. Busted Knuckles may have had the right idea all along. Good luck!

1heckinboi

This morning I did have it happen a few more times, I’m starting to think part of what is causing it is the cold weather, yesterday wasn’t as cold as today. Which makes a little more sense since later in the days it’s fairly warmer and I wasn’t having any issues.

As with the occurrences this morning I was able to play around with the pedals and see what worked and what didn’t, anytime my brake light was on I was not depressing the brake, some times when I pressed the gas during that I would not get a response, i then lifted the brake towards me with my foot and pressed the accelerator. Car responded and drove fine. I haven’t had any time to look at the switch just yet but I’ll definitely take a look this weekend

1heckinboi

Just an update, actually had time on Friday at work to mess with the brake switch. Pretty easy to get to and adjust, I only had shortened the cushion between the pedal and switch a bit. Ever since then I’ve had zero issues with the flickering and acceleration.

I’ll probably update this in a week just for anyone else who may experience this issue, but looks like everything is in the clear

Knucklebus

That's the cheapest fix for a Lexus you may ever find.

bclexus

What gives you the impression that the previous owner offloaded the car for that reason?