Dead Pedal and Throttle Lag- Summary of Problems Requested

Do you know if these calibrations are available for dealers to install, or would Toyota need to make them available first?… of course assuming it might actually be helpful.

I’m thinking about going to test drive a couple ‘24s when they are on the lot to see if I can recreate the issue.

 

Good to know. I’ve seriously thought about trading in for ‘24, but can’t quite stomach the cost increases. Would come out ~$8k down… hoping Toyota does something to take care of this

 

Same here, will have to take 10-15k loss to get out of my 2022. Which I'm very much considering... Unfortunately

 

The Calibration numbers being different means that something changed but we don't know what It could be a hardware change and a software logic change but it could also be the same logic just running on an updated Part.

My guess when the part numbers are available the 24's will have a different part number for the ECU and TCU modules themselves.

That being said new calibrations for Older models are only released though TSB's however what could happen is that there could be a new revision of the original TSB number with an updated calibration rather than a new TSB number being released.

If a new 22-23 TCU cal ID gets released it would be incremented from the old release so it would be: 8A2100C03500

 

Here is my general flowchart on how to possible move the issue forward if you have this.

First off if you have a 2022 or a 2023 manufactured in 2022, you should first have the dealer check that the latest TCU calibration is applied. If the dealer is avoidant on this on this then ask for a "Health Check" printout and it will show is the software is up to date or not.

If you are past that point and still have the issue, then its a good idea to jot down a quick doc with the issue and hand that into service. At this point if they don't have any answer at least ask the question if they can open a TAS case and get direction from Toyota Tech. (If they opened a TAS case the case number should be noted on the workorder)

If they don't at least do that then I think its a good idea to then call brand engagement, I think specifically mention that you had a drivability complaint, the problem is intermittent and the dealer did not reach out to Toyota technical assistance for further guidance even when asked.

USA people can file a safety complaint with NHTSA here https://www.nhtsa.gov/report-a-safety-problem#index. If you had the "I almost wrecked thing" I think its ok to log a complaint there right away. As I write this there are dozen or so similar complaints logged across the 2 model years.

Unfortunately right now as far as we can get in the process is getting the service depts to open TAS cases.

I just say some dealers are more willing to spend some time that others, but keep an open mind with dealing with the first line that its not likely they can directly fix anything and the process is going to take time.

 

Thanks so much for this flowchart. I called in a favor to a VP here in the Washington state area who has put me in touch with a service engineer who has volunteered to do some driving and spend some time with the truck since the dealer and Toyota brand are just doing circles. Next Tuesday I’m set to bring the truck in and they’ll likely have it all week. I’ll report back if I make any progress.

Meantime I am also considering trading this so I can just move on. I’m at a break even point so I’d be out about $3k. I just want to know if anyone on here has a 24 and/or can speak to improvements over 22/23?

 

Question to everyone here that might have insight. Could our trucks with this problem be candidates to be lemon lawed? I’m aware of the requirement (4 repair attempts or 30 days in a shop), but have never gone through the process.

 

No, because we can't reproduce the tissue when going to the dealer, so there's no issue

 

Say I were to get the dealership to admit to experiencing the issue in a ride along… just considering options.

 

This is good because this is the ultimate steps needed for someone to figure out the issue. If you do get some one on one time maybe ask what Data Points are useful specifically for logging this behavior with tech stream because that's the piece I'm looking for.

 

Cool, I don't know if Carista can show you the data but look at output shaft speed 0 rpm and NT speed >= 100 rpm or output shaft speed 50 rpm and NT output speed >= 150 rpm while the vehicle speed on the dash is under 6mph.

That seems the most consistent condition I've found that the vehicle seems to dead pedal at.

 

So like every Saturday I do my testing and logging. I have a few interesting observations.

#1 Consistent problem with the throttle between commanded voltages 0.878 and 1.015V. Resting voltages are between 0.820 and 0.859V, After pressing the accelerator pedal the commanded voltages do increase consistently however the readings of the Throttle Position pid (in degrees) and Throttle Sensor Position (in percent) Consistently in this range the pids stay at 0 or briefly jump up to what they should be for a frame or two and return to zero. Values beyond 1.015V seem to respond normally. Sometimes though I do have normal readings in this range but when the lag is happening its 0. It suggests that the 0 values may be incorrect or even confusing the ECU, as there should be a tiny bit of actuation occurring.

One thing I notice is that occasionally in my drives my idle will be extremely jumpy, and wondering if those that have the lag also have the very jumpy idle. This could point to a problem with the throttle sensor, motor, or idle/throttle learn process.

#2 Pressing the accelerator at low speeds beyond 24% causes the ECU to start targeting boost and boost cannot be generated at the rpm's we are at. I'm not sure if this is intended but this could add additional time to the lag felt because of the initial delay condition. I don't think this is a problem but pushing the pedal past 24% could cause the truck to get very jumpy after it wakes up because its going to start adding the boost right in when the RPM's come up.

#3 New! On a recent drive I logged one of the really strong dead pedal events shortly after starting a drive which is very typical. I noticed this random Actuation of the waste gate that occurred shortly before trying to apply throttle and I'm not sure if some routine that is testing the wastegate happened to kick off at the same time I induced the dead pedal condition making the thing feel worse. Anyway I only have this one data point but I don't fully understand what is going on there. This does not happen on every logged dead pedal event.

Unfortunately I really need more technical data about what the values should be in to really know what's going on.



As far as the throttle goes I'm going to try the full idle learn procedure. The best I can see this happens once the engine is idle for 5 minutes after the Engine Coolant temp is higher than 176F and all climate controls and loads are shut off.
I am also going to clear all learning values because I have a tool that can do that.

Some of these values with the throttle and accelerator are standard OBDII pids so it may be possible for more people to data log that without special tools.

 

Closer examination of the lower line is the requested position of the throttle, Had the throttle opened just slightly, no lag or dead pedal would have probably been felt.

 

RLC177,

Do you think getting hold of a truck whose owner hasn’t experienced throttle response problems and collecting the same data from it while at the same time trying to cause a throttle lag be helpful? From your most recent data, the throttle position sensor is suspect. Comparing it to another truck without history of throttle lag could reinforce that.

Keep up the good work as it seems you are making progress. I for one haven’t experienced any of the throttle problems, but if a component goes bad, it can happen.

Tom

 

Yeah my sample size includes one truck so having data from multiple trucks could be helpful.

It took me about 2.5 months to figure out a system to collect the data that I'm getting. The current process isn't ready for prime time and I imagine very few people would be able to get the data I have, but If I find a cheaper, and easier system I will write up a guide.

 

Hey there fellow pissed off people. I wanted to float a different theory by you specific to the “dead pedal” issue. To confirm what we’re talking is completely different than the hesitation/lag issue.

The dead pedal issue has happened 4 more times in the past 2 weeks which to me means the problem is getting worse or there’s a common trigger. That said, has anyone given any thought to the problem being caused by a safety system? I was backing up earlier and the truck came to an abrupt halt with alarms as it thought I was going to hit something. It made me start thinking about the dead pedal. A few observations:

• the dead pedal always happens after the truck begins moving forward slightly. Maybe a few feet.
• Each time it’s happened I’ve always been entering or crossing traffic where it then goes dead for a few seconds.
• It comes back alive and I can resume whatever activity I’m doing.
• 
  Today I was making a right turn into traffic in the far right lane. the cameras would have sensed vehicles in the lane across from me. Perhaps it’s sensing the steering angle or lack thereof and comparing that against what the cameras and sensors see and then responding accordingly. Not saying that the vehicles response is ok but I’m just trying to see from you all if there could be any weight to this thought.

Thanks,

Shaun

 

Wouldn't safety system also beep in some way or show something on the screen?

 

I've logged data with delay/dead pedal events with TRAC and VSC disabled (which also disables pre collision) so I think I have ruled that out. However its certainly possible they could interact with the condition. The most consistent order of events transmission shifts into 1st gear as you come to a near stop.

So far the events I've logged last 300-600ms before the throttle clearly starts to respond, but it certainly felt longer than that.

The condition you explain though can happen as seen in this video: https://youtu.be/rpnOTpcrWFc?t=166 (at 2:50)

The truck dings and the red "BRAKE" message is clearly seen on the dash. It looks like its triggered because the camera saw the red car still in front of the truck.

 

Yeah, really good points. I’m just trying to find some commonalities but the data is certainly stronger than my voodoo theories.

 

I'm not sure arguing with yourself will satisfy your need to feel speed fantasies, but I'm rooting for you.

 

The forum's purpose is to help and assisstify Tundra enthusiasts.

The belittling portion is just icing on the cake.

 

I am wondering that too. My truck is June/23 build and at times it does feel like it hesitates off the line. Maybe one of these would help?

https://youtu.be/yWKMOirpg8w

 

I inserted the wrong link.

 

The ECU is encrypted so it can't be reversed engineered like the 2nd Gen Tundras, and 2nd and 3rd gen Tacoma's. The community on the tacoma's did a lot of work refining what the stock calibration did and that's how I learned about all this stuff so When I started over there.

Based on what I can log, a pedal controller isn't going to help any as the accelerator signal is ignored. The device would probably work for you better if you are consistently feeling like you want to press the pedal further than you need too, it helps with that stuff.

 

Goddamned right.

 

I'm still having cake whether you like it or not.





aaaaaaaaaaahahahaha!
@BTundra21

 

Yes I would. I would pull up to in my truck... the one that doesn't suffer from throttle lag or exploding bearings or a complete lack of tow hooks and tell you everything in between small bites of a delightful Entenmanns.

@BTundra21

 

@BTundra21 Lots of great people and info here on this Forum, so don't give up on us yet. Sometimes we joke around, that's what we do, so don't take it personally, I personally have made that mistake before so I think I understand.