Got stuck on the motorways on the way home from the office yesterday and the car started to play up (I need a new rad and the gearbox needs its cooling sorted) gears would stay in higher range for longer etc. Then my old problem resurfaced - the head unit (for nav radio etc) started to reboot. The longer I stayed in the slow moving traffic the more times it rebooted. As soon as i was off and moving again it settled down and didn't do it again all the way home.

Now as I said I know I need a new rad but I couldn't for the life of me link the hot car with the head unit rebooting? Interior of the car was nice and cool and the electronics in the rear of the car wouldn't have been affected by the car sitting in traffic.

Any ideas? "On first name terms with my local Dealer......now."

'61 Plate 5.0SC Autobiography - in Black ——— Gone
'53 plate 4.4V8 Vogue Bonatti Grey inside and out. ----- Gone

My old car did that once - I think I gave all the cables in the boot a wiggle & made sure the connections were good. I may have also done a battery disconnect/reconnect - but it fixed itself.

I hope it turns out to be simple

Mine does reboot from time to time of its own accord, no specific symptoms, although it often happens on the way home from work, about five miles from home, after climbing a a short hill

Suggest get works on rad and box sorted to see if this is the reason? .
Experience is the only genuine knowledge, but as time passes, I have forgotten more than I can remember
Volvo V70 P2 2006 2.4 Petrol 170bhp Estate SE
MG Midget Mk1 1962

Previous: L322 Range Rover TDV8 3.6 2008; L322 Range Rover TD6 3.0 2002; P38A Range Rover V8 1999

Logically speaking when you are in slow moving traffic your engine is not revving very high, so the alternator is maybe not outputting enough voltage to charge the battery

I'd start by checking voltages.

That's an interesting point - I hadn't considered that, better give the battery a check. "On first name terms with my local Dealer......now."

'61 Plate 5.0SC Autobiography - in Black ——— Gone
'53 plate 4.4V8 Vogue Bonatti Grey inside and out. ----- Gone

Mine rebooted on startup during the winter when the battery was a bit low, usually at the same time as slow lock operation (including steering lock) tired cranking and "Special Programs Off" message from TR (presumably this was rebooting too)

Was only driving 3 mile a day with seats, screen and steering heating on and have an oldish battery too so although I didnt measure the voltage I could tell the system was rebooting due to this - after a charge-run every now and then everything was noticably snappier and the NAV reboot was gone.

Hope yours is similar cause.

stop car

pull fuse 49

get out lock doors

wait 5 minutes

unlock and refit fuse 49

job done

Last edited by Gazellio @ Prestige Cars on 7th Jul 2013 8:22am. Edited 1 time in total

Gary - what does that sort then? "On first name terms with my local Dealer......now."

'61 Plate 5.0SC Autobiography - in Black ——— Gone
'53 plate 4.4V8 Vogue Bonatti Grey inside and out. ----- Gone

It sorts the constant reboot issue and appears to be a permanent fix

I had something like this happen on my old BMW with a Mk 3 sat nav. It was a faulty (cheap) disc that the computer could not read easily that caused it to reboot. Changing to a new disc solved it. Tom

Current Drive
2011 4.4 TDV8 Autobiography - Santorini Black - Ivory Leather

Previous Drives
2004 Model Vogue Td6 (Touchscreen) - Java Black - Parchment Leather
1994 RR Classic 3.9 V8 Soft dash - Niagara Grey - Grey Leather
1972 Series III SWB Safari - Green (Hand Painted) - Black Plastic

Ok fuse 49 trick done - will see how that goes "On first name terms with my local Dealer......now."

'61 Plate 5.0SC Autobiography - in Black ——— Gone
'53 plate 4.4V8 Vogue Bonatti Grey inside and out. ----- Gone

Remedy should be immediate ?

Right finally spent some time diagnosing this - it turns out it is the nav computer that is causing the problems with reboots. Taken it out of the car and the radio etc all work fine with no rebooting - but I am back to the horrible screen display that feels circa 1970

Going to try a new sw upgrade on the nav computer and put it back in the FF "On first name terms with my local Dealer......now."

'61 Plate 5.0SC Autobiography - in Black ——— Gone
'53 plate 4.4V8 Vogue Bonatti Grey inside and out. ----- Gone

Probs with a weak laser mis-reading the nav disc can also cause reboots.
Laser is not difficult to replace or have replaced. 
RRC 2Dr, RRC 4Dr,
P38, and 2 L322s
(wife thinks I'm nuts - prob right, too)

Ordered one and will see if that sorts it - thanks for the advice. "On first name terms with my local Dealer......now."

'61 Plate 5.0SC Autobiography - in Black ——— Gone
'53 plate 4.4V8 Vogue Bonatti Grey inside and out. ----- Gone