I have a 2007 Volvo S60 2.5 Turbo the timing belt was changed water pump changed brand new battery brand new starter relay when you put key in a car and you turn it on it's all lights come on but it will not try to turn over Like The Engine is Dead Makes No Sounds so I put it on the computer and I got the code PO727 engine speed input circuit no signal... HELPP!!

 

was the car running after the timing belt was replaced or did all this work done at once? I wonder if your replacing the battery set off the immobilizer. Have you tried locking and unlocking the doors with the key fob 5 times to see if it resets?