Hello All,

I have a 1999 V70 AWD XC wagon with approximately 165,000 miles on the odometer. About a year ago, my middle daughter crashed this car (one car accident). Luckily she wasn’t hurt, but the damage was extensive, and required the replacement of the subframe and a complete new “nose” off a donor car. The engine was removed from the car and re-installed (the frame had to be straightened) .When I got the car back I noticed the ambient temperature sensor was registering outdoor temperatures that were almost 20 degrees hotter than the actual temperature. This sensor plugs into the plastic air dam and is located just under the bumper on the passenger side. Initially, I thought the sensor had not be installed properly after the rebuild or had been damaged due to the collision.

I confirmed the sensor (Part # 91256603) is the only ambient temperature on the car. I also confirmed that it had been properly re-installed. Finally, thinking the sensor was damaged, I ordered a new one from Volvo, and installed it. No change. I still get temperature readings that are almost 20 degrees higher than actual temperatures. I confess, the temperature readings do drop slightly when the car is in motion. But I will regularly register temperatures in excess of 100 F. when standing still and I don’t’ live in Arizona!

Has anyone else had this experience? If you so, what did you do? Of course I can live with it, but it is convenient to know what the “real” outside temperature is. Thanks to all who respond in advance.

Hugh

Is it off 20 degrees at night, or early morning before the sun gets high?

B.B.

It doesn’t matter whether it is day or night, the difference in temperature is always present. At the worst it can be 20 degrees on average is about 13 degrees. I have two ’96 850 wagons that have a similar temperature sensor, and I will jump in them just to compare temperature readings. They will be almost identical, whereas the XC will be elevated. It just isn’t the heat from the engine throwing off the readings either. It is consistently elevated. I just wish I could get accurate temperature readings while driving along. That’s why I hoped replaced the sensor with a new one would fix the problem.

Hugh

Hi Hugh,

The sensor is most likely just a thermistor and it changes with temp.
I tried to get a good wiring diagram for your 99 v70 and got part of a wiring diagram so I went to the 850 diagram to see what the do.
Its a two wire connection Green Black in the 850 and the harness goes to the trip odo via a connector in the dash 24/13

I would measure the sensors with an ohmmeter to see if one of them is way off.
The other thing is where the car was in a crash, look carefully at the sensor harness and see if it might have been crushed, maybe a lousy connection somewhere if the body shop had to splice that harness. Added resistance from a crappy splice might give you those sypmtoms.

Bill