Gas Pedal Stops Responding on Highway

[tah8436]

Just completed a piston soak on a 2016 Hyundai Santa Fe 2.4l. It was burning 2-3qts per 1k miles.

However, ever since the piston soak, the gas pedal will become completely unresponsive intermittently at high speeds. Turning the car off and back on fixes it. The car starts up normally and idles smoothly, and there is no check engine light present. We also replaced the PCV valve at the same time. What could be causing this random total unresponsiveness?

Thank you.

 

[HemiBenny]

No check engine light, but have you actually hooked up and scanned it?

A “gas peddle” that doesn’t respond intermittently or at all, has me questioning the accelerator position sensor. Has it coincidentally gone wonky on you?

 

[The_Jeff]

I'd give the battery a disconnect/ reconnect then let the throttle body relearn. Barring specific instruction, idle it for a while then drive at different throttle openings.

 

[skyactiv]

Just completed a piston soak on a 2016 Hyundai Elantra 2.4l. It was burning 2-3qts per 1k miles.

However, ever since the piston soak, the gas pedal will become completely unresponsive intermittently at high speeds. Turning the car off and back on fixes it. The car starts up normally and idles smoothly, and there is no check engine light present. We also replaced the PCV valve at the same time. What could be causing this random total unresponsiveness?

Thank you.

The Elantra doesn't have a 2.4L from the factory.

 

[HemiBenny]

The Elantra doesn't have a 2.4L from the factory.

Another “new” member testing us out?

Good catch. 1.8 or a 2.0

 

[tah8436]

The Elantra doesn't have a 2.4L from the factory.

Ope, my bad, it's a Santa Fe. Also have a 2016 Elantra in the family unfortunately


HemiBenny - Scanned it and no pending or stored codes.

 

[tah8436]

I'd give the battery a disconnect/ reconnect then let the throttle body relearn. Barring specific instruction, idle it for a while then drive at different throttle openings.

Thanks, I will give this a try since the terminals look a bit crusty.

 

[Number_35]

Welcome, @tah8436!

If you have a Scangauge, you can select the TPS (throttle position sensor) display, and watch it as you press on the accelerator pedal. Look for a linear response, without any gaps.

 

[Marcozi]

The first step in diagnosing a problem is to scan the computers for codes.

 

[martinq]

Just completed a piston soak on a 2016 Hyundai Santa Fe 2.4l. It was burning 2-3qts per 1k miles.

However, ever since the piston soak, the gas pedal will become completely unresponsive intermittently at high speeds. Turning the car off and back on fixes it. The car starts up normally and idles smoothly, and there is no check engine light present. We also replaced the PCV valve at the same time. What could be causing this random total unresponsiveness?

Thank you.

What you are experiencing is "limp mode" or "protect mode". I had this happen on a Nissan with a CVT problem. The ECU will just cut the throttle under certain conditions and it would not even set a code. Extremely frustrating and dangerous.

Definitely check ALL your wiring and connections. I would also do a search for all the TSBs related to your vehicle. There could be some firmware updates for the some of the ECMs.

 

[tcp71]

go through the electrical connections you separated during your last maintenance. The most logical place to start. Look for pins pushed in or not making contact.

 

[tah8436]

Thanks, all. Cleaning the throttle body, disconnecting and cleaning battery posts seems to have solved it.