I have a 2000 S40 with about 100K miles on it. I was driving the other day day and my car started accelerating without me touching the gas. I tried shifting it to Neutral and it continued to accelerate. I finally pressed the break hard enough to get the car to stop. The out door temperature sensor is giving me a false reading. Is there a chance the two of these are related and does anyone have any ideas what might be wrong.

Thanks

 

it could be problem in your gas pedal sensor or trothle body, i think that 00 s40 are fully ekectronic- no cables

 

My guess would be the throttle position sensor. I would have it towed to a mechanic to be checked. No way would I drive a car that might accelerate like what you said happened.

 

I have seen a bad coolant temp sensor and thermostat cause the car to do that.

 

His car has a cable.
The S40 didn't get the fully electronic setup till 2004.5

 

Thanks for all the ideas. It ended up being a bad coolant temp sensor.

 

Glad all is well now.