Connected, not recognised, message

[Coulomb]

when the message appears the 12V battery shows 11.8V, it is a false data because the tester writes 12.4V.

I assume you mean that a multimeter reads the voltage as 12.4V when the car reports 11.8V. That is quite a large difference, and I agree that this seems like it could be part of the problem. However, I doubt that the car would avoid starting because of an 11.8V measurement.

Perhaps the car is seeing glitches that the multimeter is ignoring. Or maybe there is resistance in the battery circuit somewhere, causing voltage sag under load. That suggests a loose terminal somewhere, or perhaps a tarnished fuse or fuse socket, or a high resistance relay contact or its socket.

If so, that sort of fault should not be very hard to find and fix, though possibly tedious and time consuming. I wonder if the dealership is worried that MG or SAIC won't pay them fully for the time it might take.

 

[MELLE]

I assume you mean that a multimeter reads the voltage as 12.4V when the car reports 11.8V. That is quite a large difference, and I agree that this seems like it could be part of the problem. However, I doubt that the car would avoid starting because of an 11.8V measurement.

Perhaps the car is seeing glitches that the multimeter is ignoring. Or maybe there is resistance in the battery circuit somewhere, causing voltage sag under load. That suggests a loose terminal somewhere, or perhaps a tarnished fuse or fuse socket, or a high resistance relay contact or its socket.

If so, that sort of fault should not be very hard to find and fix, though possibly tedious and time consuming. I wonder if the dealership is worried that MG or SAIC won't pay them fully for the time it might take.

puff..now i'll call assistance and start the adventure again.
MG or SAIC shouldn't make dealers worry if they want to sell cars here.