The Beloved 3rd Gen Transmission About Got Me Killed This Morning

I'm very proud of you. Impressed, even. I seriously doubted that you would actually put in the effort, & low & behold, I was wrong. I can live with that loss. You went above & beyond. That is definitely respectable... but... you did still ask a question specifically about people you didn’t know & answered it for them before they had a chance to respond as if you knew what their answer would be. That's still ridiculously dumb. Doing that will always be ridiculously dumb. Don't do that... But great job, dude

 

Its not just the 3rd gen taco. My 2018 camry is the same... companies now a days are trying so much to get those MPG's thats its hurting the driving experience.

 

Did he really almost die? That cannot be answered. Maybe he was bored and felt like starting an epic dumpster fire. Maybe he’s just lying for attention. Who knows?

 

First post is 2 weeks ago 2nd post is a clip from today's post.
Interesting.

 

Pretty sure I lit that fire. But I have had my truck hunt for gears and fall flat on its face a couple of times. I think it was just a bad set of circumstances related to the gear I was in, speed, and what I was asking it to do. I don't blame the truck or the Toyota engineers. Shit happens, but I'm making sure it doesn't happen again.

 

What exactly is PC doing to correct it?

 

No you didn’t light the fire. You added fuel.

 

I'm speculating here, but I think it does a better job at keeping the throttle body open by modulating and amplifying the pedal signal. Simple but effective. I don't know about you or anyone else, but without PC, if I want to maintain constant acceleration, I have to press the pedal down more every time it shifts. If not, it may skip a gear. Nothing sucks more than making a slow right turn and having your truck go from 2nd to 4th, especially when filtering into traffic like the OP stated.

 

I hate to be throwing rocks at your fine work, but that's what science is about, right?

How does the scan tool determine these timestamps, and can you make it update faster? It looks to me like the time stamps on this are just when the scan tool *received* a given datapoint. They're all about 280ms apart (except for City - I suspect different settings were used on that one). Since they're so far apart, the values they indicate don't reflect the real performance of the system. For example in your 14.9%, 0.2s delay scenario, the real value in the vehicle computer could have changed at any point between the time that packet was sent to the tool and when the next packet was received - but the time of that change would have been missed by the tool entirely.

 

It was set at 0 seconds. I think the issue was my setup. I simply mashed the pedal to the floor and ran it up to approximately 4k RPM. Not the most scientific method, but I was interested in instantaneous throttle response. I'm also still learning the software. I may go back and slowly increase the throttle over a longer period of time and see what happens.

 

The 5v is on or off? I am not sure I understand you here. The 5v is off with the ignition off and on when the ignition is on. The ECM doesn't vary or turn the voltage on or off. It sends reference voltage to all the sensors and then the sensors send back a varied signal back based on their measurements. The TPS included. The #1 TPS returns a .5 to 4.9 volt signal and #2 TPS returns 2.5 to 4.9 volts signal depending on pedal position. There is no on and off. This is constant DC voltage.

Another thing that the TPS signal does is send a signal to the transmission for throttle pressure to speed up shifting by increasing clutch engagement pressures. Again, no modulation, this signal is constant.

 

That's why I used the quotes. It's not literally on or off. The circuit may still be energized with .5V, but it doesn't do anything. When the voltage increases to 5V for whatever reason, it serves as a signal for something else to happen. We often refer to this as when a voltage goes from low to high.

In other words, the 5V signal voltage serves as an 'on' / 'off' switch for another circuit. I haven't seen the schematic for the pedal, so this may not be applicable. Just going off the systems that I've worked on.

 

Yeah, this is gonna be a tough one to sort out with a scan tool or software, since you're relying on the system under test to report data as fast as it can, but reporting data isn't its priority. An oscilloscope would shine here.

 

So are you looking at the pedal TPS, or the Throttle valve TPS. The pedal TPS is the input from the driver while the Throttle TPS is a reference sensor letting the ECM know where the actuator has the throttle valve set to. If the pedal TPS is at .5v then the ECM sees this as idle and purrs along in idle. Only adjusting RPM based on A/C clutch engagement, Alternator charging needs or cold start cycle. Above .5v to 4.9v, the ECM sees as demand for torque and adjusts the RPM thru the throttle actuator as needed based on the pedal TPS.

 

Neither. I'm just speaking about circuitry in general. I agree with the guy I replied to.

 

Come on guys, have some respect.
This guy's transmission almost got him killed!
Like died dead kind of killed.

 

Big deal. I’ve been almost dead killed like a million times already.

 

We should have a moment of silence for all of the 4-cylinder automatic transmission owners who have no doubt been sacrificed at the altar of fuel economy by way of poorly shifting transmissions.

 

Come on, he was driving a Tacoma.

These trucks can take a bashing and the occupants are protected by the high strength steel and airbags.

Whoever OP cut off darting out into heavy fast moving traffic, that's a different matter.

 

That was me you replied to. I was just trying to get clarity. I think the horse is dead now. I will stop beating it.