Facelift MMI Rebooting Itself When Satnav Following a Route

MikhailCompo

MikhailCompo

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I have an S3 8V facelift.

When following satnav the MMI reboots after about 15 minutes of driving. The screen retracts into the dash and the unit completely powers off before coming back on (without previous destination routed, very annoying).

The problem started after I took it for an MOT and service at my excellent Audi specialist indy garage. I've asked them about it and they can't offer any suggestions without bringing it in which is a pain as they don't offer courtesy cars.

This might be useful: On a hunch I had read another user experienced same problem when the battery was on its way out. So I replaced the EPS battery with a good Bosch AGM battery, recoded.
Now I still have the same problem, but whereas before the screen would fully retract before booting back up after a second, the unit comes back up before the screen has time to fully retract.

So clearly changing the battery has had some impact, but it's not fully resolved.

Can anyone offer any advice for a permanent fix?
 
sounds like a power fluctuation problem... clean both battery clamps (mating surfaces with the battery poles) than remove the main ground wires on the engine clean mating surfaces 9wire brush) and put them back. That should make sure the flow of power doesn't get interrupted. But if it doesn't cure it, the alternator is not working right or the aux belt is due to be changed rather sooner than later.
 
Not sure about battery connection. If this was the issue I would see other electrical issues, surely? Also, the reset always occurs after 15-20 minutes of driving.

Doesn't ring true that it's a connection issue to me.

To verify either of your theories, would monitoring the voltages help? I need to know what the reference values should be however. How do I establish a baseline?
 
if you have a form of monitoring the voltage, check it before turning on the navigation and after you set the navigation than during use, especially when it decides to go off...
 
MikhailCompo said:
Nope.
Click to expand...
Had units in the past where corrupt data on the sd card caused them to reboot.

Scan the vehicle to see if there are any obvious errors would be a given but do you have to be driving for this to happen or does it happen if you sit stationary for 15mins, engine on and off?
 
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Not sure about battery connection. If this was the issue I would see other electrical issues, surely? Also, the reset always occurs after 15-20 minutes of driving.

Doesn't ring true that it's a connection issue to me.

To verify either of your theories, would monitoring the voltages help? I need to know what the reference values should be however. How do I establish a baseline?
 
DJAlix said:
Scan the vehicle to see if there are any obvious errors would be a given but do you have to be driving for this to happen or does it happen if you sit stationary for 15mins, engine on and off?
Click to expand...
No errors reported in OBDEleven.

I've not run my car for 15 mins without moving, don't really fancy that as it doesn't do it much good, but what would it prove either way?
 
MikhailCompo said:
No errors reported in OBDEleven.

I've not run my car for 15 mins without moving, don't really fancy that as it doesn't do it much good, but what would it prove either way?
Click to expand...
It would prove that if you are stationary, it's not the happening because of motion of the car. In other words nothing is loose or makes false contact.

Ps having the car idle doesn't do it any harm other than burn fuel.
 
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