Electric park brake can not exit service mode (voltage too low)

[Chris1234]

Hello!Does anyone can help me with EPB.I entered the service mode to change brake pads on the back wheels and now I can’t exit the service mode.I used Autel EV tool

 

[OriginalBigAl]

Youtube might help? There are videos where both using service mode and not are available but not MG specific.

 

[fred12345]

Hello!Does anyone can help me with EPB.I entered the service mode to change brake pads on the back wheels and now I can’t exit the service mode.I used Autel EV tool

There were some posts on the forum about this, from memory, someone suggested a solution but another had to tow it to MG to be fixed. Not worth doing DIY without proper knowledge of the systems. There is service manual available for download from MG for a small fee.

 

[Chris1234]

Problem is solved.Used EPB module with same part number.
1.Disconnect low voltage battery.
2.Replace control unit
3.Connect low voltage battery
4.Read live data to figure out what is the position of the actuators stored in the control module(I guess it should be always in closed position as it is not possible to leave that module with opened calliper actuators ,the reason is that there is nothing else to hold the car at place except the rear callipers.There is no safety engagement in the gearbox )
5.If your callipers are in opened position connect directly the actuator motor to +12 V power supply to close them . Apply little tension on the pads and disconnect the +12V )
That’s all guys .I hope that could help you too!
No special programming or adaptation is required! Plug and play!

 

[Ronnie H]

Hi Chris

I have the exact same problem with a mg hs locked in maintenance mode after using scan tool to retract motor .problem I’m having there isn’t a epb module on the hs ,it must wrong through another module .any ideas

Thanks Ronnie

 

[Lovemyev]

I think even the dealers where having a similar problem after using the computer, to set the HB service mode, so I believe they have now refrained from do so.
They have appeared to favour releasing the HB in the normal fashion, then disconnecting the connection plugs on both HB actuators.
Replace the pads and pump the foot brake, before reconnecting the plugs and turning on the car.
this is purely from memory here I should add.
Why did you replace the pads, not worn out ?.
Replacing the brake disc's due to corrosion I would guess ( then the pads of course ).
You did pump the footbrake first of course ?.
Long shot, but you could try disconnecting the 12 volt battery, leave 10 minutes for the modules to completely close down ( there is a delay ) and then reconnect.

 

[Ronnie H]

Hs doesn’t have a seperate epb module ,like the zs.just found out it’s the module that’s part of the abs pump

£850 + vat

Then labour
Coding etc

Could be over £1500 bill


PLEASE EVERYBODY DONT DO BACK DISCS,PADS ON A HS USING A COMPUTER TO RUN ACTUATORS BACK ,CHANGE THEM MECHANICAL


Back discs where absolutely toast .pads where fine .19000 mile

 

[Lovemyev]

Back discs where absolutely toast .pads where fine .19000 mile

I guessed that would be the case.
MG dealers would get the work all of the time, if the price of their parts were not so overpriced.
For what are not that special imho.

 

[Ronnie H]

I guessed that would be the case.
MG dealers would get the work all of the time, if the price of their parts were not so overpriced.
For what are not that special imho.

Absolute disgrace.ive done about 50 rear discs and pads in my time with epb .and this is never happened.

 

[Lovemyev]

If definitely a different set up that has caught a few people out, including some of the tech’s in the dealership !.
We had one of the rear wheels fail to release the HB on our first ZS EV.
It was a call to the MG to get the car recovered.
The guy from the recovery service removed the handbrake actuator motor on our driveway and the spine of the motor had stripped and motor was just spinning and spinning.
He managed to release the handbrake by winding back the calliper with a toques bit.
The dealer replaced the calliper and the motor under warranty, the parts were on order for over three weeks.
Have tried locating a unit from a breakers ?.

 

[Ronnie H]

If definitely a different set up that has caught a few people out, including some of the tech’s in the dealership !.
We had one of the rear wheels fail to release the HB on our first ZS EV.
It was a call to the MG to get the car recovered.
The guy from the recovery service removed the handbrake actuator motor on our driveway and the spine of the motor had stripped and motor was just spinning and spinning.
He managed to release the handbrake by winding back the calliper with a toques bit.
The dealer replaced the calliper and the motor under warranty, the parts were on order for over three weeks.

They won’t warranty my issue .haven't even asked .

And the probably won’t even touch it as it has after market discs and pads on it

 

[Lovemyev]

Have you considered a breakers yard ?

 

[Ronnie H]

Yip ,I’m on the case .anything from £30 -£160

lol £30 for a £850 + vat abs pump/module lol

And my plan is unplug the the master plug from the one in the car and plug into the scrap yard one and see if it gives me access to the brake module via the scanner ,if it work .the I will change the whole lot round and bleed up the brakes etc


The theory sounds good lol

Plus I will put another battery with jump leads to the battery in car so voltage doesn’t drop (I don’t have a battery tender )

That may have been the issue these modules are so sensitive to voltage dropage now

 

[Lovemyev]

Sounds like a good plan to me !.
I would not think the new module would need to be coded to the car, so it should work straight out of the box .
I have noticed that all of the EV techs connect a 12 volt battery maintainer first, before carrying out any diagnostics work.
The 12 volt batteries are vey small in capacity these days on EV’s, therefore they quickly become discharged.
When the car is in standby mode, it is receiving NO charge into the 12 volt battery.
Good luck and keep us posted !.

 

[Ronnie H]

 

[Ronnie H]

Guys just an update

Got my sons scanner ,autel better software

So went into epb module directly and went in to special functions ,software reset

Doing so took it out of (maintainance mode )

Then back in replace auctators

It re calibrated and bingo

Everything working again

Just to let yous know

That was on a 2020 MG HS 1.5

It’s not a hybrid or electric

Probably posted on the wrong forum from the start lol

But again may help evs and hybrids

 

[Lovemyev]

What that’s a relief .

 

[Ronnie H]

Omg . It was actually a fist pump moment with my brother when I heard the actuators working lol

The thought of £1500 plus for a module replacement at MG lol