I apologize for the long post, but I am looking for any thoughts on this weird issue.

I got the ABS/DSC traction control not available, warning lights on the dash of my 2012 XF and I took it to the dealer to have it looked at. They couldn't find anything, and said it was throwing a C0034 code for right front wheel speed sensor. I did see the same with my code reader. They ran some tests and nothing came up as a red flag. So they reset the error code and road tested, but couldn't see an issue, or replicate warning lights.

Drove it for about half a day, and after being parked a few hours, it came back on. Dealer said bring it back, and they will look at it, when my airbag recall is being done. Had to wait for the parts.

In the meantime, I have been able to clear the warning and get about 2-3 days without it coming up. One of the things that seems to be a common factor is, when I use my radar detector after it has been fine a few days, the warning appears. Could be coincidence.

What is also odd is that after I start the car, a second or third time, with the ABS/DSC warning being lit, I also get the adaptive headlight warning lamp and check engine lamp. After driving 5-8 minutes, the ABS/DSC and adaptive headlamp warnings go out. The check engine stays on until I reset it. They all stay off at that point.

I did some searching and found that a lot of things are caused by a low/bad battery. I used an old analog multimeter I have, and it looked like it was around 10 volts without motor running. I had it checked at a local auto parts store, and they seemed to think it was low. 9-10 volts, based on his equipment. He also thought the alternator might be bad, since his test seemed to indicate that also. But he admitted he was new and wasn't sure about the readings. He wanted me to come back and have the experienced guy look at it the next day.

Second opinion needed on battery, so I called AAA and got a free check. They said it was 12.6 volts without motor running, and alternator was putting out 14.1 volts. So now i am confused.

How do you get two completely different readings on one battery?

I am planning on making an appointment with the dealer, once the airbag part is in.

Any thoughts or things I can check in the meantime would be appreciated.

Love the car. I have been enjoying it for about 8 months. But hate these gremlins.

 

Might be surface charge. Check it without engine running after an overnight stand, with headlights on. A meter can be had for cheap!!

 

so I load tested the battery with a decent model battery tester, and got a reading of weak, 11 volts. Car had sat all night and was tested without it running. Then put headlights on without car running and got same weak setting.

I then did a charging system test and got a good reading. Over 14 volts. So I believe I'm good there.

Guess that means it is a bad battery and needs to be replaced. I am hoping this may resolve my random abs/dsc and adaptive headlight warning lights issue.

 

Ok. Just to satisfy my curiosity I had autozone check battery for me. Yeah I'm crazy like that.

Let the car sit overnight. Drive 1 mile to shop and they tested battery. 12.6 volts. And 14.1 for the alternator. Starting system tested good also.

So i am going to concede it isn't the battery. Have appt with dealer to check it out next week. The code it throws points to the front right wheel speed sensor. Let's see how good they are at finding it during the first visit.

Will update once I have s solution.

 

Final solution to issue...

Bad right front wheel speed sensor. Caused ABS and stability control warnings. Also caused adaptive headlight warning and check engine light to come on.

Total cost to fix at dealer......672.00. Parts. Labor and tax.

Don't know if that is a lot or not. Don't care. Car is fixed. And she is back to her old self. ��