Have a 2007 xc90 v8 with 89K on it. Had dealer installed tow package about 3 years ago. Finally excited to use it we prepared to buy a 2000lb tent trailer a few weeks ago. As I felt as if the transmission got "stuck" on acceleration twice in a few days time, I took the car in for a full diagnostic. Tran was fine, but AWD was not. They updated the software but said a 20%chance it may not work. Within a few days I received another anti-skid message, took it back in and they replaced a sensor. It was running fine, and brought up no codes for anything else so we got the green light to tow. Bought our trailer at a reputable dealer and service shop, they set us up with a Prodigy radio frequency braking system, tested and paired the unit and we drove off for home. Prior to getting home we stopped at a vacant parking lot to practice reversing and maneuvering. About 20 mins into this, our AC died. A bit later car power died down, THEN we get a "low voltage" message, a slew of other malfunction messages and then we hear what we now know to be our battery boiling over. Fried the battery, the alternator, etc to the tune of $1500. Warranty is excellent still and is covering about $900. A bummer about the $ but our real concern is that neither Volvo tech nor the trailer tech can say for sure what caused this. Of course volvo thinks its the trailer, the trailer tech thinks it the car. Not interested in pointing fingers at either...just want to tow safely and not fry car parts. I suppose since I had sensors go out in the last few months maybe the alternator was starting to fail but one would think that would have had a code during diagnostic? My husband is feeling really leary and is now looking at other tow vehicle options Anyone had this scenario or have suggestions?

 

either the alternator or battery wen bad and fried the other, not uncommon for ANY vehicle, and not a huge red flag. The extra load may have pushed the bad component over the edge. Id say your luck that it happened now/at home instead of on a road trip.

 

Perhaps your alternator was bad to start with, and the error messages in the transmission were a symptom of that, before you even got the trailer?

Bad voltage/alternator issues can cause a slew of problem for an electronic system that requires a tight voltage range to work properly.

Do the trailer brakes seem to be working well? If the tow package is dealer installed, then surely it is fused and there should be no way a problem in trailer wiring could cause a problem back in the engine bay.

 

I do hope you are both right!! It seems that would be a logical explanation except for the fact I would think a bad alternator or battery (or low) would have come up on the diagnostic 2 weeks prior but who knows. Thinking we will take it to a local shop to have the voltage tested with the trailer on and off now, see if there is any change. I hate paying labor for that but it will give me a little more peace of mind before taking it on the road...

 

does anyone know if you have someone other than a dealership install a hitch if you HAVE to update the software in the car? i'm new to the volvo forum and my 2006 xc90. thanks.