LKA & Rear Driving Assistance System Indicators indicate fault after garage replaced boot panel

[YaR]

Apologies if this issue is solved on another thread...

My MG4 Trophy was in for a repair after someone reversed into the back. It needed a new panel on the boot lid however prior to going in there were no fault indicators showing and all the electrics appeared to work.

However, I collected it today and I have persistent LKA and Rear Driving Assistance System indicators lit up and neither of these systems work. However ACC, TJA and the reversing camera/sensors are working perfectly so it's very unlikely to be a hardware fault with either the front or back camera/sensors. The main battery discharged from 60% to 25% when in the garage because I think they left the car on for some time. I did a quick fast charge on the way home to 50%. The 12v battery has 12.6v on it. The car drove perfectly normally all the way home - 10 miles on the motorway, 5 miles on country roads.

Now I know plenty of people on here would be more than happy if LKA was disabled by default, but I'm not one of them.

Any idea what could be wrong and if it can be fixed by rebooting/discharging something if it's a software issue?

I could always take it back to the garage and tell them to fix it, but that's a hassle I'd like to avoid at this stage.

 

[Martinonline]

You can try disconnecting the 12v battery as this seems to reset an number of faults indications.

Did the car go to an MG4 Dealer? If not, then they may have inadvertently introduced a software error.

 

[mg4mc]

If you disconnect the battery, disconnect from the battery sensor rather than the battery terminal. If you reset the battery sensor it can take a long time for it to recalibrate itself.

 

[fnegroni]

They might have disconnected the 12v battery and didn’t fully reset everything? Do as suggested to disconnect 12v battery then the system hopefully will allow you to recalibrate everything properly

Are these the indicators you see?

 

[YaR]

Are these the indicators you see?View attachment 21673

Yes, the yellow LKA indicator with the dashed centre line and the RDA system indicator. No other warnings other than the yellow triangle with the exclamation mark which is just pointing out the other two. The message centre has a message about LKA detecting a fault, but nothing for RDA.

Did the car go to an MG4 Dealer? If not, then they may have inadvertently introduced a software error.

It went to an MG approved bodyshop, but not a dealer.

I might brave disconnecting the battery, but I might not as I don't want to brick the car when I've got some in person work meetings tomorrow! Maybe I should contact the local dealer...

 

[tsedge]

If you disconnect the battery, disconnect from the battery sensor rather than the battery terminal. If you reset the battery sensor it can take a long time for it to recalibrate itself.

Can you explain this more? Where is the battery sensor? Why does this make a difference? Thanks.

 

[mg4mc]

Can you explain this more? Where is the battery sensor? Why does this make a difference? Thanks.

The sensor (EBS) is attached to the negative battery terminal. There is an outgoing cable bolted to the sensor.

1 - Outgoing cable bolt
2 - Bus connection
3 - Battery connection

The quote the MG service guide (via Google translate!)...

Note: In order to avoid reducing the accuracy and service life of the battery sensor, unless the battery is being replaced, do not remove the EBS from the negative terminal of the battery. And when installing or disassembling EBS, you must operate carefully to ensure it does not suffer any damage.

Note: After the battery sensor EBS is reinstalled on the battery, it needs a minimum of 4 hours of rest time is required to obtain accurate battery status information.

Note: For power outage operation for repairing electrical related faults, just disconnect the negative pole cable to the battery sensor EBS instead of disconnecting the negative pole directly [from the battery] pile head. This reduces the time it takes for EBS to obtain accurate battery status information.

 

[tsedge]

Thanks - I need to read those service guides properly! Appreciate all your help.

 

[YaR]

Disconnecting the battery didn't help. It gave me every error message under the sun - they all went away after recalibrating the windows and steering except for the two original error messages!

Looks like a phone call to the dealer tomorrow.

 

[tsedge]

Sounds like something wasn't properly reconnected in the back panel.

 

[YaR]

It's in the dealers (glyn hopkins, cam) for a 'software update' which they expect to fix the problem. Update what from what to what, I couldn't say.

Sounds like something wasn't properly reconnected in the back panel.

Bingo. Apparently they'd forgotten to plug one of the sensor modules back in. Easy for the dealer to fix but completely unacceptable on the part of the body shop.