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Drive-By-Wire Throttle Controls On My Suburban = Evil

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January 21, 2020, 05:12 PM
4MUL8R
Drive-By-Wire Throttle Controls On My Suburban = Evil
Losing power at 70 mph while on the interstate, I exited at a looping ramp and made it about 300 yards up the road. Dash lights blazing with warnings, I was able to pull off on a shoulder far enough to avoid having my police friends come and sit with me. My AMA towing service came in less than one hour, and took the 2007 156K mile vehicle to my company lab. My wife had to leave work to pick up the dog in the SUV, then meet me at the lab to ride me home.

What broke? Whatever connects the metal to the pedal and the thing to the floor. https://www.youtube.com/watch?v=nT3P_9QkqW4

The engine would only idle. No power. Could not even drive up the wrecker ramp bed.

Who invented this reportedly unreliable GM system? I know it is widespread. I know it is "better." I just want them to recognize that I was nearly killed. OK, maybe only slightly possibly a little bit inconvenienced. But, now I have to fork over about $350 for a throttle actuator and a throttle pedal sensor, we think, to ensure I can actually use a vehicle.

Can you imagine what would happen IF I had been towing the rated 7K pound travel trailer? That's the plan for this bus. No hope. The trailer would be on the side of the road. The truck would be in a shop somewhere. We would be in a hotel racking up $150 per night costs.

I am glad I have a spare vehicle that works, and a "dump truck" that also works. This Suburban will likely eat $2K more in repairs, if I am lucky, over the next few months.


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Trying to simplify my life...
January 21, 2020, 06:10 PM
ArtieS
If it's going to eat that much more in repairs, and you aren't going to trust it to pull your trailer, maybe it's time to put it out of your misery and get something that you can trust, and won't nickel-and-dime you to death?

I'm not trying to be a wise-ass, but it's likely that all sorts of electronic controls and features are going to start to snuff it in a 13 y.o. vehicle, not to mention things like the air conditioning compressor, and other expensive, but limited lifespan components.



"I vowed to myself to fight against evil more completely and more wholeheartedly than I ever did before. . . . That’s the only way to pay back part of that vast debt, to live up to and try to fulfill that tremendous obligation."

Alfred Hornik, Sunday, December 2, 1945 to his family, on his continuing duty to others for surviving WW II.
January 21, 2020, 06:25 PM
motorheadjohn
I've had a throttle cable break. When a part breaks, you're screwed either way, sitting on the side of the road. The cable was cheaper to replace, though.
January 21, 2020, 06:56 PM
.38supersig
It would have been worse if you were driving a Toyota Camry.

Drive by wire failure results in wide open throttle. Can't shut the engine off. Electronic transmission will not respond. Brakes won't be able to do much in the long run...

Later they had to reprogram the car to have the transmission downshift and the start button to shut the engine off. Nothing here to see. Nope. Must have been the floor mats!




January 21, 2020, 07:08 PM
PowerSurge
quote:
Originally posted by .38supersig:
It would have been worse if you were driving a Toyota Camry.

Drive by wire failure results in wide open throttle. Can't shut the engine off. Electronic transmission will not respond. Brakes won't be able to do much in the long run...

Later they had to reprogram the car to have the transmission downshift and the start button to shut the engine off. Nothing here to see. Nope. Must have been the floor mats!


It WAS the floor mats getting wedged against the accelerator pedal. NASA and NHTSA investigated and found the same thing.


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The fool hath said in his heart, There is no God. Psalm 14:1
January 21, 2020, 07:27 PM
.38supersig
Fair enough.

Guess what I was trying to say here is that there are worse things that could have happened than just coasting to the side of the roadway.

Hopefully it won't set you back as much as that. Made for a crappy day either way.




January 21, 2020, 08:07 PM
HRK
Happened to my eff Juan giddy in 5 pm traffic lucky a guy let me over to curb idled off the road

Vac lines had gone bad 3 of them, at 140k miles

Stuff wears out.



January 21, 2020, 11:21 PM
92fstech
quote:
Originally posted by motorheadjohn:
I've had a throttle cable break. When a part breaks, you're screwed either way, sitting on the side of the road. The cable was cheaper to replace, though.


I can splice or rig a throttle cable on the side of the road to get me home. I can't reprogram a computer or replace a circuit board (not to mention troubleshooting the problem is a WHOLE LOT easier!). In 20 years of owning old rusted out vehicles, I've never had a throttle cable break in my car (motorcycles and dirt bikes...that's another story). I have had issues with electronic throttles in cars several times, though.

How much does it cost to build and install an electronic throttle compared to a simple cable? And what is the E-throttle doing for you that the cable isn't? It's just unnecessary complexity with little or no benefit, and a host of negatives.
January 21, 2020, 11:40 PM
GWbiker
The 1987 Mercedes Benz 300D (Diesel) had a little rubber grommet at the throttle plate where the accelerator cable attached too. Over a period of time and motor heat, this little grommet would soften, wear and pop out, leaving driver with a idling motor and nothing else.

Guess where it happened to me? In front of the MB dealership.

I asked the MB service manager why that little grommet was not replaced during a scheduled maintenance.

His answer: MB didn't think it was necessary.


*********
"Some people are alive today because it's against the law to kill them".
January 22, 2020, 12:39 AM
egregore
I ran into a Hummer H3 (3.5 "Atlas" inline five) with a failed throttle body that, once shut off after the reduced power message came on, could not even be cranked to start back up. At least, once figured out (the throttle codes had to be cleared to enable the starter), the throttle body was easy to replace, better than needing a starter, a 5-hour job.

A couple of makers (Volkswagen and Saab) years ago had electronic throttles that had a backup cable if the electronic part failed, but no longer. With stability control being mandated Roll Eyes an electronic throttle is necessary. Cruise control is just a matter of adding switches, wiring and programming in the PCM*, no need for a separate servo and its accompanying cable.

*Powertrain Control Module

This message has been edited. Last edited by: egregore,
January 22, 2020, 06:14 AM
Georgeair
How about all those brake light control switches that fail? We should go back to hand signals! For the chirren.



You only have integrity once. - imprezaguy02

January 22, 2020, 09:38 AM
dynorat
Drive by wire is driven by CAFE, and other schemes, gimmicks, and shenanigans. Can't have you controlling the drive-train unless you pay the added taxes and fees for the up-level enjoyment.

I hate the econo class calibrations that make it feel like the connection between the pedal and metal is a finicky rubber-band.

Also need to keep "new product" money making schemes going. It gets complex, but consider a simple part like a door panel retainer.

Why does every every new model need to have unique new door panel retainers. New launch repairs are always being done with used, damaged, or cobbled from available parts. Its not like retainers a new thing, and you would think the constant "cost savings" and "lessons learned" mantra they preach would dictate using common methods and retainers on something as routine as panel and trim retainers.

The costs of design, proto, sourcing, building and supplying production approved parts is HUGE. Last I heard, it was $20K in costs just to issue a new part number. Too many top guy and gal hypocrites making millions and driving billions with vested interests in new technology, material, service, and subscription providers to actually do the right thing and sell durable, proven, and reliable technology.


________________________________________________________
You never know...
January 22, 2020, 01:45 PM
ShouldBFishin
quote:
Originally posted by .38supersig:
...Drive by wire failure results in wide open throttle...


Haven't had any issues with the 3 Camrys we've had, but I did have that happen in the 80's driving a Dodge Omni Horizon. The throttle cable stuck when I was accelerating to get on the highway. Stomped on it to try to get it unstuck and then it was stuck to the floor Eek .

Funny thing was a mechanic from the local Dodge dealer who was going to help with a different car that weekend was with me at the time.
January 22, 2020, 03:42 PM
PowerSurge
quote:
Originally posted by ShouldBFishin:
quote:
Originally posted by .38supersig:
...Drive by wire failure results in wide open throttle...


Haven't had any issues with the 3 Camrys we've had, but I did have that happen in the 80's driving a Dodge Omni Horizon. The throttle cable stuck when I was accelerating to get on the highway. Stomped on it to try to get it unstuck and then it was stuck to the floor Eek .

Funny thing was a mechanic from the local Dodge dealer who was going to help with a different car that weekend was with me at the time.


.38supersig’s post was BS. Read my other post above. You’re not going to have any issues with that Camry’s throttle.


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The fool hath said in his heart, There is no God. Psalm 14:1
January 22, 2020, 11:14 PM
jimmy123x
This went bad intermittently on my 2005 expedition when it was under warranty (less than 3 years old). Of course shutting the vehicle off and turning it back on reset it and it worked fine, until it happened who knows when the next time...….the dealer couldn't find the issue because it didn't set off any codes, until it did it for them...……

Honestly with 156k miles, I would expect things to go bad.....that's a lot of miles for any vehicle.
January 24, 2020, 11:08 AM
4MUL8R
OK, the good news. Drive-by-wire diagnosis and repair completed. Cost = $0. Well, I will buy a friend a few items in return for his work. And, the exact throttle body I needed that he had in his garage, left over from a LS swap into a 1958 Mercedes-Benz.

Let me tell you, a functional throttle is an amazing thing. Based on the difference in so many things, the original throttle body must have been on death's door for a number of months. Here are the things that have changed:
1. Response to pedal motion = great
2. Transmission shift points different
3. Transmission downshifting upon increased throttle is instantaneous
4. Throttle position on cruise is more closed
5. Power delivered is far greater (I was at 80 mph on a lane change in about six car lengths)
6. Spark knock at moderate acceleration is gone

It is all better. The system can work well. I still think the failure mode = evil.


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Trying to simplify my life...
January 24, 2020, 04:50 PM
.38supersig
My bad.

Its not like I'm Ken Jennings.




January 25, 2020, 09:03 AM
egregore
quote:
Let me tell you, a functional throttle is an amazing thing. Based on the difference in so many things, the original throttle body must have been on death's door for a number of months. Here are the things that have changed:
1. Response to pedal motion = great
2. Transmission shift points different
3. Transmission downshifting upon increased throttle is instantaneous
4. Throttle position on cruise is more closed
5. Power delivered is far greater (I was at 80 mph on a lane change in about six car lengths)
6. Spark knock at moderate acceleration is gone

Interesting. This will be helpful to me in my own work.

While it is difficult to quantify, you may have extended the life of your transmission. The force with which the clutches are applied varies with engine load on this transmission. Over a long enough time, excessive slippage can wear them out. Jasper gives a list of things to check or clean (the MAF sensor being one) with their transmissions for this vehicle.

This message has been edited. Last edited by: egregore,
January 26, 2020, 04:44 PM
pbslinger
My understanding is that the motors that actuate the throttle plate are quite powerful and can cause injury to fingers. Like if you had someone actuate the throttle, you put your fingers in, and they shut off the key, or let foot off throttle. (assuming throttle plate goes to idle if you shut off key)
January 26, 2020, 08:11 PM
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It is also good to have a vacuum gauge so you know when you are lugging the engine and down shift when using a manual.


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