Heard a strange whining sound outside the other evening, went out and the high beams on my wife's XC90 were on and the washer pump was running/howling. The car was locked, she had been home for a couple of hours. Strong pungent smell inside the car, I assume the pump had been running, pumped all of the washer fluid out, and started burning the motor up when it ran dry. I could not turn off the lights or get the pump to shut off, I had to disconnect the battery.

She has gotten the DSTC Spin Control Off message recently, from searching, it seems like her steering angle sensor is failing. Should I assume that the high beams/washer pump running are also a symptom of failing electronics in the steering column?

I let the car sit for about a week, reconnected the battery yesterday and the symptoms were still present.

 

A good first step would be to scan all the control units with a compatible scan tool. Looking for relevant self diagnostic codes. Since the switches for both of those malfunctioning items are connected to the steering column module - that might be a hint. That module under the steering wheel is not a common replacement item. The contact reel is, but that part should not cause washer and high beam problems. If you don't have immediate access to a compatible scan tool, How about simply removing the ts and wiper switch and seeing what happens?

Sometimes water gets into the CEM and causes strange problems also.