Dead Pedal and Throttle Lag- Summary of Problems Requested

Hi y’all. Question for those of you who have experienced or continue to experience the dead pedal and/or throttle lag issue. I’m experiencing both and I’m in a vicious cycle with Toyota "brand engagement" and my local dealer. At its highest level the dealer is telling me either they cannot recreate the dead pedal issue or that the throttle lag and surge is normal driving behavior. The truck has been in four times now with the same responses; Toyota corporate wont do anything because the dealership says its normal. I have however had a tech ride with me and acknowledge the throttle lag but when it came time to fill out the notes he said it’s normal. I’m at a loss because these issues are far from normal; the dead pedal has caused me to almost get t-boned twice now and the throttle lag has caused me to almost rear end other vehicles because of the “jump/surge” when it does come back to life.

That said, I’m going to cull the forums/threads and see if I can piece together some sort of commonality and present that to Toyota. Would any of you be willing to put together a short summary of what you’re experiencing? We need to get to a point where Toyota can no longer turn a blind eye. I for one plan to push this one to full resolution which is either 100% fix or a buyback.

Feel free to toss out some thoughts here or direct message me.

Thanks in advance for the help.

 

I would find the tech that said it was normal and shove my foot up his.... I mean uh, what's the deal tech guy. You see it happening, note it correctly.

 

I put my findings so far in the other thread.

But as far as what you can ask if you are driving with a tech and that tech doesn't bring a laptop and log data though the trucks ODB port, the drive isn't very useful. You can try asking for that and then have them review the data where the delay was seen.

There isn't any smoking gun that I can find as the conditions to cause the issue but its most consistent when you lightly tap on the brake and get below 6mph then get back on it. The thing though is it seems to be most consistent with a high transmission input speed while the output shaft speed is very low. This isn't something you cant directly control and can only see with a scantool. Of the potential lag spots I only experience the lag maybe 1-2 times out of 10 rolling stops. Most of my drives are under 10 minutes and under 10 miles so I'm not sure if that is a factor. Its entirely possible more than one thing is going on as I've not had data logging for any really long delays that are very rare, but I have dozens of delays logged between the .5 and .75 second range. I also have dozens of drives in the exact same route with the same conditions and no delays logged.

My dealer has been very receptive to my concern but the process is slow for me because I can't drive much ( 1000 miles/6 months) and I don't have a lot of time to spend down there having them go over it again, but I will bring the additional data back when I can make an efficient trip and hopefully get this looked at + recall work + key fob. Like I said in the other thread we opened a TAS case and they wanted to reset the TCU memory and let it relearn for a bit before going further so I'm in a little holding pattern at the moment.

As far as getting something quicky it would be great to work with an engineer that knows how the ECU/TCU works to narrow in specific data, I'd certainly sign any NDA to get that more direct coms. Its rather a very slow and random process while I collect data and try to look for correlations.

Some general advice:

See if getting harder on the brake before accelerating changes the behavior any, this is something new I'm testing as I'm very light on the brake all the time and coast to a stop.

Resist the urge to press the pedal further if no response. I think it might be better if you need to pull out quicky to left foot brake torque the truck but haven't experimented much with that.

If I am dead stop its been perfect, but I noticed that from the computer data what feels like I stopped may not be a dead stop unless I was stopped for more than 1 or 2 seconds.

I'm still hopeful there will be a new calibration as more trucks get on the road and have similar issues. I'd say that its entirely possible for that to take another year. On the 3rd gen tacoma's the 2016 ECU/TCU final calibration didn't get released until July 2018.

For me the problem isn't bad enough that I want to try to get out of the truck.

 

Mine has never done it. That said, one of the Tundras I test drove did and it was almost undrivable. It reminded me of my first 7.3 Powerstroke where nothing happen until the big wheel spun up. The truck I drove did it pretty consistently during a 1hr test drive. I doubt it's fueling because the map would be the same from one to another. Doubtful it's fuel quality. Good luck isolating the issue. If I was guessing I'd be looking at grounds on the harness or voltage at a sensor. Extremely difficult to troubleshoot.

 

2022 tundra Trd Offroad
On rolling stops it will consistently delay between the time I apply throttle and the engine responding. Usually around a second or so. If you continue to apply throttle it will spin the tires when it finally decides to go.

It was better for 500-1000 miles after having the "Surge" TSP done then came back. I'm over 100 miles from a dealer so haven't gone back but will bring it up when I go in for my last free maintenance. It sucks the joy out kd driving the truck.

 

I’m dealing with this too. I visited my dealer two times and they were unable to recreate the issue. I forgot about it and hoped for a fix to come out. Now, 6 months later, I’ve almost been in accidents a couple of times, one of which could have been severe at high speeds. Also, my wife comments every time it happens since it throws her head to the seat rest. After much frustration of “living with” the issue, I called Toyota directly. I have a case manager assigned and they are going to work with my local dealer to figure something out. Sounds just like your scenario so far, except my dealer has been very friendly. We’ll see where it goes.

 

Me too.

 

Thank you for all the responses! This is exactly what I’m looking for, additional hard data and details plus anecdotal comments that it’s not just me with the issue or just being overly sensitive which is how they’re trying to position this thing!

 

I’m following your other thread closely as it appears you’re the only one who has logged this much data based on real world driving.

I’ve said it before but I think this is an organizational issue. No one technical is talking with the people driving these trucks on a daily basis. It’s a horrible game of telephone. My escalation point from the dealer is the Toyota “brand engagement” group whose job it is to shut me up or make me feel like everything is good instead of an additional line of direct problem solving.

I would contribute to a fund to see RLC177 engage directly with Toyota engineers both as a technical evangelist and consumer advocate for all of us drivers/owners.

My question is where do I go from here? That’s where I’m stumped.

As I see it I have three options: continue spinning in the mud making slow to no progress given their horrible organizational structure. I can continue trying to escalate for the greater good or I can look out for myself and try to get this problem vehicle off my hands since no one with Toyota seems to give a sh$!.

 

I think for the rolling stop the transmission is still shifting. I think @rlc177 is on the right track about coming to a complete stop. Many new vehicles have a similar issue with the rolling stop and I think it’s a side effect of having more than 6 gears and a really low first gear. It’s normal because it’s a fundamental architecture problem.

 

Mine definitely has the annoying throttle lag issue. I don't drive too fast, so it was hard for me to notice the dead pedal, but seems like my truck got that as well as I've almost been t-boned couple weeks ago.

 

The best fix I've come up with is to always come to a complete stop. My conspiracy theory is that it's intentional, designed to change our driving habits

 

A question - some of the members with 2023s claim that they got zero of throttle lag @Breathing Borla

Do we know if only 2022s have this issue?
Do any 2022s do not have any throttle lag issues?

If 2023s don't have this throttle lag issue, then does that mean that Toyota modified their throttle response programming to fix this issue?

 

That rolling start thing is definitely a symptom. I think when I coasted up hill and let my foot off the pedal that’s when it feels like it may die. Doesn’t happen often but when it does I can tell. It’s like a timing thing or something. But alas it died while on the highway.
https://youtu.be/T0JKU6VGRfI?si=oCzpvfedaSJyAgMT

 

My data shows the lags I have logged I am in 2nd gear and it downshifts to 1st when tapping the brake at low speed.

Something I haven't tried is disabling VSC (by long holding the traction control button) I'm not sure if its something to do with Traction/VSC because it really seems like the power is being limited to almost nothing rather than ignored. The trac light is not illumining though.

 

The 2022's had a bigger problem that was (at least partially) addressed by the TCU calibration update.

Mine is 2023 post TSB so it came with the update from the factory.

Its unclear if this is a incomplete fix or there is some other issue not addressed.

If someone gets a hold of a 2024 and can pull the Calibrations with a scantool we'd know if they updated anything secretly.

 

This is exactly how I have avoided it. It’s nearly non existent if you do this. I also still believe that the non hybrid trucks have some sort of ghost code in there and are expecting an electric assist motor to kick in .

Teh other day I did a rolling stop and it happened as I was getting into a busy road.

 

My 2023 did this a few times. Now I tend do drive it in S8 gear setting. (S9 on highways) And so far it has been running very smoothly. Not a fix, more like a bandaid. In S gear setting it downshifts sooner and up shifts later so RPMs are higher slightly when driving

 

My basic understanding from the 3rd gen Tacoma I would suspect the ECU/TCU acts in a similar manner as all modern Toyota do.

The accelerator is tied to a "demand request", the ECU/TCU based on the current conditions figures out how to best meet that demand. Everything is controlled by the ECU.

Tacoma's had a lot of dead pedal on the highway because at the high speeds and gears you couldn't accelerate slowly because you bashed into a throttle limit for the overdrive gears. You'd have to mash on the pedal much more than expected to cause a downshift.

In this case I don't think the problem in the demand. I suspected that the ECU thought it could meet demand at low speeds and therefore didn't add throttle. At least in my testing just mashing or flooring it does nothing as well. If you hold the pedal constant it wakes up eventually and the accelerator position seems irrelevant.

In my data logging I'm not seeing any smoking gun as to what changes to have the thing suddenly respond again.

It seems though at least some youtube reviewers noting a delay/lag sometimes with the hybrid models too so the issue may not be the same thing that was address in the non-hybrid TCU update.

 

I would be interested to see if anyone had hooked up a Throttle Commander (or similar) and is continuing to have the issue???

 

So what do we need to see the same data as you are?
Could you please post a link for cable that we connect to the laptop to connect to obd and software we need?

 

I still had the throttle delay issue...

I drove up to a stop sign before a busy road, stop, then when about to drive, I start rolling slowly to get ready, then start accelerating about mid-range only to find that truck was crawling out onto a busy highway like a turtle, I then punched it and nothing happened for a good 1-2 seconds... While all other cars slam their breaks to avoid tbone me

 

What is your theory on why it is intermittent on some trucks and non-existent on others?

 

I do think dead stop dead pedal happens but its much rarer than very low speed. But you did say you started rolling a bit so it could have been in the conditions to have the rolling stop.

 

There is a variety of things that could potentially be used, basically you need a adapter and software that can read Toyota Specific PID's and log them for playback later.

The specific stuff I use is a tatrix openport 2 and the actual Toyota Techstream software. Though I think you can use the torque app and an approved adapter to do the same things.

Techstream Lets me log the most data and easy to setup pid lists, some other things I've tried only allow 8 pid's to be logged. I can't and won't explain how to get the Techstream software due to obvious reasons, and Don't want to be peoples tech support. I just know how to do this from the ECU Mod Community for the Tacoma 3rd Gen's.

The PID's I look at:

I put a * at the ones I feel show there is a dead pedal (Accelerator is pressed and Throttle doesn't open and remains at 0)

Vehicle Speed
Engine Speed*
NT Sensor Speed*
Output Axis Speed*
Accelerator Position*
Throttle Sensor Position*
Shift Status*
Stop light SW*
Boost Pressure Sensor
Intake Manifold Pressure
Target Boost Pressure
Wastegate Valve Position Sensor Bank1
Wastegate Valve Position Sensor Bank2
Calculate Load
Vehicle Load
MAF Sensor Bank1
MAF Sensor Bank2

I'm dumping to a CSV file in techstream and then loading in a Windows app call FlowCSV Viewer to try to munch though the raw data.


Here's an example of what I felt was an abnormal start, there is a period of very little activity flowed by a surge because I'm Pressing further then I have to lift because I spin on the gravel. Each division is .125ms there is about 500ms delay before a slower response then a much lager response, the whole event is about 1.5 seconds. The output shaft speed in this example is 0 when the acclerator is applied, but the vehicle speed PID is lagging way behind. (I did find some toyota documentation that said this is because its calculated from the wheel speed sensors)

I created a formula IsLag where if the Accelerator is >10% and the Throttle is 0 to set a flag so I can find them quicker.

 

2nd Example what "normal" looks like very similar vehicle speeds and way different response.

 

I'm not really sure but I do think that it might be a thread the needle type situation where a very specific set of parameters needs to be set, but ultimately it need an engineer who knows how the thing works to figure out. Every time I think I find the condition I find another situation that is very similar and doesn't have the issue.

The thing is that it matches the TSB T-SB-0111-22 exactly:

"Some 2022 – 2023 model year Tundra vehicles may exhibit one or more of the following drivability-related conditions:  Hesitation from a complete or rolling stop (worse when vehicle is cold)."

However we already have the Updated TCM Calibration listed. Be interesting to talk to the person that developed the previous fix and understand what was changed.

 

Interesting but the Cal ID change could be they fixed something or that they just used a different Processor.

 

not sure that really tells us anything does it since its model year to model year?