[chaadster]

Hey all,

A weird problem popped up this weekend as I neared the end of a 5hr drive down to Ohio. I’d been cruising along a two-lane at about 55mph when I came to stop sign. When I was ready to proceed, I pushed the throttle pedal and the engine didn’t respond. I looked down and saw the Service Electronic Throttle warning and that the engine was still running, just at idle or near idle speed. With cars behind me, I gave it full throttle and crept my way to the shoulder.

I shut down the car and restarted it; it fired right up, no MILs. However, when I tapped the throttle— still in Park— the revs continued to build after I lifted my foot. I waited a sec as they went up to 3k, at which point I turned the car off.

Confused, I pulled my OBD reader; no active or stored codes. Weird.

I decided to restart the engine and got the same raising revs issue when blipping the gas in Park. The revs built quickly with no sign of letup, so I shut the car down at about 3k rpm again.

Being in the boonies near the WV and KY borders of OH, I figured since it idled normally at startup, that I’d try to select Drive before hitting the gas, and to my surprise I was able to then give it gas, drive a few feet, then brake to a stop without the revs building. I decided to carry on the few miles to my destination, and arrived there without problem, however, when I put it in Park, the revs ran loose again.

I left the car sit for two days, figuring I would try to drive the nearly 2hrs towards Cincinnati, where there’s a dealer, and whether I made it or not, I’d be closer to the dealer and to civilization. Well, when we pulled out this morning, the car seemed fine and I decided to head towards Dayton instead, because it was more on the way home.

I wound up driving nonstop 4.5hrs, almost the entire way back, without any sign of trouble. When I did stop for gas, no problem. When I got to town, I stopped at the bank ATM and when I put it in Park, revs surged.

So I’m home, and planning to call the dealership for an appointment tomorrow, but I wonder if anyone has any idea what would cause such behavior? I do have an AFE airbox and dry cone filter on it, but this seems an electronic issue, particlarly considering also how the throttle MIL vanished without a trace. Thoughts?

 

[beta2alfa]

You still have the Go pedal+ hooked up?

 

[Go_a_way1]

Do you have two floor mats and or is it secure. This sounds dumb but working at a dealership (Chevy) this happens far more often then you would think. Sometimes its just that simple and a floormat gets pushed up and presses the peddle slightly. You won't notice when driving because the brakes can easily overpower the slight press of the peddle.

 

[chaadster]

You still have the Go pedal+ hooked up?

Oh, yes, I do; forgot about that. I could turn off/remove as a test.

 

[chaadster]

Do you have two floor mats and or is it secure. This sounds dumb but working at a dealership (Chevy) this happens far more often then you would think. Sometimes its just that simple and a floormat gets pushed up and presses the peddle slightly. You won't notice when driving because the brakes can easily overpower the slight press of the peddle.

I do, and I’ll double-check the placement, but wouldn’t the revs still build if the throttle was depressed while the brakes engaged? Or, wouldn’t revs build when driving if foot off gas but mat still pressing on it?

 

[chaadster]

I did check floor mats— they’re factory— and placement is very secure and well away from throttle.

 

[chaadster]

Thinking of @beta2alfa ’s mention of GoPedal+, I’ve started the car this morning, and through idling and throttle blips, have it now at 3 bars of engine temp without any unusual behavior (that’s with GP+ normally engaged in Sport mode, as it has been for pretty much all of the past 2 years).

I’ve opened the GP app and looked for an update function: nothing. I’ve toggled the system on/off, trying throttle blips in both conditions: no problems. I’ve toggled the mode to Custom, Eco, and Sport: no problems.

Given that the dealer most likely cannot fix a problem that is not apparent— i.e. normal behavior, no codes— I guess I’ll have to wait and see if I can figure out conditions under which it happens. I don’t think I’ll get anywhere telling dealer to drive it 4.5hrs straight then check!

If I can get it to do it again, I’ll also test whether GP status has any impact.

Thanks for the ideas so far, folks. Any others also welcome.

 

[Serpico]

Thinking of @beta2alfa ’s mention of GoPedal+, I’ve started the car this morning, and through idling and throttle blips, have it now at 3 bars of engine temp without any unusual behavior (that’s with GP+ normally engaged in Sport mode, as it has been for pretty much all of the past 2 years).

I’ve opened the GP app and looked for an update function: nothing. I’ve toggled the system on/off, trying throttle blips in both conditions: no problems. I’ve toggled the mode to Custom, Eco, and Sport: no problems.

Given that the dealer most likely cannot fix a problem that is not apparent— i.e. normal behavior, no codes— I guess I’ll have to wait and see if I can figure out conditions under which it happens. I don’t think I’ll get anywhere telling dealer to drive it 4.5hrs straight then check!

If I can get it to do it again, I’ll also test whether GP status has any impact.

Thanks for the ideas so far, folks. Any others also welcome.

Try resetting and doing a calibration on the Go Pedal.

 

[chaadster]

Try resetting and doing a calibration on the Go Pedal.

Hmm, I’ll need to look that procedure up, as I didn’t see any way to that in the app. I’ve been using a GoPedal or GoPedal+ for the past five years, and have apparently not only forgotten I had it, but also anything about it as well! Ha! Thanks for the suggestion!

EDIT: Madness just informed me that there is no reset or calibration procedure for the GoPedal+

 

[Alpha]

The only explanation for a runaway throttle and no codes is the GP... Just ditch it

 

[chaadster]

The only explanation for a runaway throttle and no codes is the GP... Just ditch it

Well, it did put up a MIL as I said, which as I understand it, should have an accompanying fault code, so that’s weird, but also the GoPedal is so, so good for this car, it’s not anywhere so simple as “just ditch it.”

 

[Serpico]

Well, it did put up a MIL as I said, which as I understand it, should have an accompanying fault code, so that’s weird, but also the GoPedal is so, so good for this car, it’s not anywhere so simple as “just ditch it.”

"Ditch it" to validate if the throttle issue is related to the piggyback device.

 

[qvfan]

This happened to me last year. But I was stopped at a stop sign. I let my foot off the brake pedal and while I was just touching the gas pedal, the engine reved, I'm thinking 4k rpm or so. I immediately slammed the brakes, but didnt need to as the car somehow knew not to actually take off. It's as if the car was in neutral while it revved. But it was in drive. It was a very scary situation as pedestrians were nearby. The issue was the seletron pedalbooster unit. I removed that device no more than an hour later and never had a problem since.

 

[chaadster]

Ah, gotchya.

 

[wingler]

Ah, gotchya.

Which GoPedal do you have? Is it the BT only version (no dongle) that strangely disappeared from the product line?

 

[chaadster]

Which GoPedal do you have? Is it the BT only version (no dongle) that strangely disappeared from the product line?

I think yes; it’s called GoPedal+, and there is no control head, only app control.

It was superceded by new GoPedal and GoPedal Bluetooth, the latter of which, like the previous, older variant of GoPedal, has a control head, but also adds app control.

 

[wingler]

I think yes; it’s called GoPedal+, and there is no control head, only app control.

It was superceded by new GoPedal and GoPedal Bluetooth, the latter of which, like the previous, older variant of GoPedal, has a control head, but also adds app control.

Thats the one I used to have as well. I just wonder why it was discontinued? Seems like something without a hard control and dangling wire would have appeal for a lot of people (it did to me), but maybe there were issues?

 

[chaadster]

This happened to me last year. But I was stopped at a stop sign. I let my foot off the brake pedal and while I was just touching the gas pedal, the engine reved, I'm thinking 4k rpm or so. I immediately slammed the brakes, but didnt need to as the car somehow knew not to actually take off. It's as if the car was in neutral while it revved. But it was in drive. It was a very scary situation as pedestrians were nearby. The issue was the seletron pedalbooster unit. I removed that device no more than an hour later and never had a problem since.

Similar and interesting. The weird response I got at the stop sign was no throttle response upon brake lift and throttle application.

How did you determine it was the Seletron unit?

In my case, I’m leaning away from it being the pedal tuner because the problem seems related, at this point, to long duration drives, something which should have no effect on the pedal tuner but may affect the ECM, e.g. operating temperature parameters. Also, the fact that the car put up the electronic throttle warning but yet cleared that itself and did not store any codes, related or otherwise, seems like a system malfunction.

I’m certainly open to all possibilities though, and will try to get this sorted ASAP…short of driving around for 4.5hrs. I just don’t want to make the 2hr drive back and forth to the dealer without a problem manifest, because I’ve been through that with those people before, and they say they can’t fix a problem that isn’t apparent, but honestly, they’re not even good enough to fix one that is, but that’s another story!

 

[chaadster]

Thats the one I used to have as well. I just wonder why it was discontinued? Seems like something without a hard control and dangling wire would have appeal for a lot of people (it did to me), but maybe there were issues?

Yeah, that’s what I like about it, too, that it’s invisible.

I did ask Eric at Madness about the new ones at some point awhile ago, and he said it was something about a different manufacturer, but did not indicate there were shortcomings, problems, or any other reason I should switch to the new one.

I have been away from the forums for quite awhile, so if there’s any street-level knowledge about the GP+, hopefully it’ll come out here. I did do a couple of forum searches, but didn’t see anything related to my issue.

 

[qvfan]

How did you determine it was the Seletron unit?

Removed the unit and never had the issue again.

However, there is a slight possibility that the issue could be a compatibility problem between the pedalbooster and a piggyback tune. Do you have a piggyback installed too?