Every once in a while, during the first startup of the day, a Traction Control failture or error message pops up in the message window before I turn the key from I to II.

I don't have a code reader, I'm not sure which reader/scanner will work on my XK8. I bought one then returned it after it created a CEL while trying to log a live data stream the two times I tried.

The car drives fine and the traction contol always works after receiving the message.

Anyone run into this? Any reason for the message but the TC works fine?

Exactly what is checked when the car is doing a system check?

 

Low battery voltage

 

I noticed that same thing on my '01 XKR after sitting for about a week. The car still has the original battery in it. I received the same warning, but the car started fine and no further traction control warnings. I am going to start again after sitting for 2 days and see if I get the same traction control failed warning. I will have my battery checked for load and voltage.

Should I consider a replacement battery, if so what brand and model is recommended for an XKR? I have seen a Gold Duralast H8-DLG recommended by AutoZone with 850 CCA. The original battery is about twice the length of current batteries on the market. Does length make any difference in battery performance?

The battery was fully drained after winter storage even though I had a battery tender on it. I was able to recharge the battery and started the car fine. No problems with the battery since.

 

Find an Interstate battery dealer in your area, have them load test yours. I think the replacement is MTP93, at least a six year prorated warranty and about $120. Nothing else for me, thanks.

The engine will still crank over fine, but the voltage during cranking can drop low enough to cause problems. Alternator charging during drive time explains why you only see the fault message on cold start.