engine management light always on

[Tommyai]

Hi all; my 08 XK8 engine management light is nearly always on. After each diagnostic check by my specialist, issue sorted, its cleared, and then reappears very quickly. They are always minor issues with little expensive work required. The last check was cleared with "it may have been a low compression on start up". 500 metres after leaving the garage its on again!.. I am very reluctant to drive it any distance (other than the 3 miles to the specialist). its now very frusatrating. Any ideas/suggestions?

[JimMann]

Hi Tommy, I am afraid the standard response to such a niggling problem is for the Forum expertise group to require more information about the car and its problem history.

As would be normal for the first piece of question / advice, tell us the age of your battery. The battery in a modern car controls so much more than just the starting demand and a weak battery may well be able to start the car without issues, but the weakness causes multiple spurious problems / messages to emerge that throws out a frustrating smokescreen.

Jim Mann

[aaj]

Hi Tommy,
As Jim has indicated, a failing Battery causes many problems.
On my '02 XK8, the first signs of Battery Voltage problems was the loss of the Window Position Memory. Others with a '08 XK will advise if a similar minor fault occurs as the Battery fails.
A Hard Re-Set is known to cure lots of funny/spurious faults. If this fails then you will need to provide further information:
What are the Fault Codes?
Do you get error messages as well as the Engine Management Light? If so what are they? What colour is the light (Red or Orange)
What are the minor repairs that have resulted from your visits to the garage following the Engine Management Light

Hard Re-Set
Disconnect the Battery
Leave for a few minutes for residual power to dissipate
Allow the 2 Cable Connections to touch for a few seconds (away from the Battery terminals)
Reconnect the Battery
If your Radio needs a Code following disconnection you will need to find this
You will loose Trip, Mileage & MPG details within the Trip system. You may also loose other Memory Features (Seats etc.)
The Alarm System may be triggered by this operation so pick the time you do this & have your Key Fob to hand
Good Luck
AllanJ

[Tommyai]

AllanJ and Jim thanks for the tips, I am having the local specialist conduct a full check as the light is still on. Without (hopefully) offending him I will bring up the points mentioned. The battery was brand new in April, but the long trips have been rare since then. I will check its charge. Many thanks for taking the time, Tommy