Aau2xr8 smartshield light flashing

[XC50077]

AU2 XR8, fitted new eagle plug leads and car seems to be running good but smartshield dash light flickers when starting and flashes quickly at idle and then increases flash speed in sync with revs. The tacho also stopped working but has rectified itself .Removed both battery leads for 3 minutes with no change. Battery is at 12.7 volts by gauge but not checked for actual voltage.
Any ideas on this appreciated. Cheers.

[russellw]

The fact that the tacho stops working intermittently is probably a clue but start by checking the battery and scanning the car for any error codes.

[XC50077]

Thanks Russell,
Had both battery cables off overnight. Cleaned earths earlier today, no difference. Then drove car about 10k just now and light has gone off and resumed it's normal pattern of flash every 2-3 seconds when parked.I had noticed the smartshield light was on but not flashing when parked for a few days earlier this week. Hopefully the problem has solved itself.
BTW the battery is 3.5 years old but seems to charge and hold voltage ok at 12.7 volts tested with my cheap multimeter.