Accelerator pedal stuck down!

[Kat Wood]

On my way to work I accelerated at a roundabout, not especially hard and quickly realised it was continuing to accelerate despite me not wanting to. I was able to use the brake but every time I took my foot off the brake it accelerated alarmingly quickly. I should point out I didn't have any assistant modes on and I was in a 30 limit with cars around me travelling at no more than 20. When I pulled up I put the car into park, touched the accelerator pedal with my foot and it sprung up, suggesting it had been stuck down. There was nothing in the foot well, no obvious reason for it to get stuck... Any advice?! I'm not a nervous driver but I must admit this has shaken me!

 

[Ian Key]

If you are sure there is nothing for it to get stuck under, car mats etc., have a word with your dealer.

 

[Vingnut]

First as Ian Key said.

If this happens again:
First brake as you did to controll the speed, then swithc foot on the brake pedal to free up your right foot. Use your shoe tip to gently try to lift up the accelrator pedal.

You do no harm to the brakes if just lightly pressing the the brake pedal enough to get the power switch to zero or below to drive to a safe spot if the accelerator pedal stays stuck. (Using the brake pedal to power the car on off).

The MG4 can also be switched between drive and neutral and back to drive while driving, but it's safer to only use the brake pedal until the situation is under controll.

I switch the car to neutral at speed when I do my weekly brake disck (rust) cleaning rutine (drive to speed, chek that no one is behind, neutral and firm braking to slow speed a couple of times). That's how I know the 4 can do this.

 

[Emptywallet]

This happened to my last night!!! Terrifying. Not mats! Cruise control not enabled. Pedal was not stuck down. I pulled out of a junction and accelerated. Lifted off the throttle and the car continued to accelerate hard (XPOWER)!! I had to slam on the brakes very hard to slow the car down.

Don't want to drive it anymore.

 

[fnegroni]

This happened to my last night!!! Terrifying. Not mats! Cruise control not enabled. Pedal was not stuck down. I pulled out of a junction and accelerated. Lifted off the throttle and the car continued to accelerate hard (XPOWER)!! I had to slam on the brakes very hard to slow the car down.

Don't want to drive it anymore.

Please report it to MG. They have to investigate this.

 

[Emptywallet]

Please report it to MG. They have to investigate this.

Already done .

 

[tsedge]

A faulty pedal is a possibility here.

 

[pollenface]

I've had this happen in other cars, a bit of spray lube on the pedal mechanism is sometimes needed

 

[tsedge]

I was meaning more the electronic nature of the signals it sends to the car.

 

[Emptywallet]

yes pedal did not stick and is not mechanical so could be pedal. Car was only delivered last week so only a few hundred miles on it now. DC charge cables will not release either!! I need to use the emergency cord in the boot. MG not helping - local dealer says earliest slot for diagnostics is 23rd Sept.

Love the car, but control systems are awful and dealers either overwhelmed or plain disinterested.

 

[tsedge]

yes pedal did not stick and is not mechanical so could be pedal. Car was only delivered last week so only a few hundred miles on it now. DC charge cables will not release either!! I need to use the emergency cord in the boot. MG not helping - local dealer says earliest slot for diagnostics is 23rd Sept.

Love the car, but control systems are awful and dealers either overwhelmed or plain disinterested.

If there are multiple issues it may need a bunch of software updates, so you need to find a dealer who is more comfortable applying those. I wonder if they have even applied the PDI updates?

You also have the option to reject if you think you've been given a lemon (it does happen).

 

[Coulomb]

I was meaning more the electronic nature of the signals it sends to the car.

All (?) cars are supposed to have dual potentiometers for the accelerator pedal. Of course, the firmware has to check these and ensure that they are not conflicting, otherwise do something safe like gradually reduce motor power.

I'm 99% sure that SAIC are doing this.

 

[Emptywallet]

Update - I can replicate the issue. Happens every time when One Pedal Drive is engaged and I give the car a decent amount of throttle. Does not happen if OPD is disengaged. So at least I have something demonstrable to take to MG.

 

[fnegroni]

Update - I can replicate the issue. Happens every time when One Pedal Drive is engaged and I give the car a decent amount of throttle. Does not happen if OPD is disengaged. So at least I have something demonstrable to take to MG.

Can you take a picture of your footwell? Wondering if something is fouling a sensor although only in OPD mode.
What MG4 do you have?

 

[Kithmo]

yes pedal did not stick and is not mechanical so could be pedal. Car was only delivered last week so only a few hundred miles on it now. DC charge cables will not release either!! I need to use the emergency cord in the boot. MG not helping - local dealer says earliest slot for diagnostics is 23rd Sept.

Love the car, but control systems are awful and dealers either overwhelmed or plain disinterested.

This is dangerous and urgent, I'd threaten to reject the car if they can't see to it straight away.

 

[johnb80]

A faulty pedal is a possibility here.

Unlikley, they have dual circuits and if both data sets dont agree it will stop the car. For both circuits to fail with a constant acceleration output is highly unlikely.

 

[fnegroni]

Update - I can replicate the issue. Happens every time when One Pedal Drive is engaged and I give the car a decent amount of throttle. Does not happen if OPD is disengaged. So at least I have something demonstrable to take to MG.

Can you take a video?

 

[Emptywallet]

Can you take a video?

Not really. Would need multiple cameras to show foot and speedo. Will let you know outcome from MG

 

[Emptywallet]

Can you take a picture of your footwell? Wondering if something is fouling a sensor although only in OPD mode.
What MG4 do you have?

It's an Xpower. I expect it to be software related.

 

[fnegroni]

Not really. Would need multiple cameras to show foot and speedo. Will let you know outcome from MG

not that difficult tbh and it would be useful as proof.
Just put the phone on a mount on the passenger headrest or get a friend to film