Expert: Roland Finston - 9/10/2011

Question
QUESTION: Hello ok so i took the battery in to get recharged get it back home and it still would not start. I have already changed out the fuel pump relay/starter relay/ and the eatx relay.  I had brought a reader today and at first it read code P0340 and P0481 the 0481 was for the fan so i just disconnected it and pluged it back in and it didn't show back up the next time i run the next again it just wont start

ANSWER: Hi Johnnie,
Have you checked fuses 14, 23, 24, and 25 in the power box in the engine compartment?
The cam shaft position sensor should be checked with a voltmeter to see if it is functioning:
Put a digital voltmeter between tan/yellow and black/light blue wires (insert fine straight pins through the insulation to make contact with the wires, clip the voltmeter leads to the pins), then turn the key to the 'run' position, and then turn the engine over by hand using a socket and handle on the crank pulley bolt at the front of the engine. As you turn it, the voltage across those wires should oscillate between 5v and 0.3v several times per revolution. If not, then check the violet/white sensor wire and see if it reads 5v to ground steadily or not. If you have the 5v on the violet/white, but no oscilation from 5 to 0.3 then either the sensor is not properly installed or the cam shaft isn't actually turning because the timing belt is broken.  Look to see if the cam shaft is turning by removing the sensor and observe whether the magnet is rotating at the face of the sensor. If you have cam sensor pulsing, then do you hear the fuel pump run for a second when you turn the key to 'run' (a humming sound from inside the fuel tank)?
If you have that, then the last things to check are do you have spark at a spark plug, and do you have compression (pull a plug, insert a compression tester to check for that).
Let me know the specifics of all those tests if you still don't find the problem.
Roland

---------- FOLLOW-UP ----------

QUESTION: Hi its my Johnie again hey I wanted to ask where is the Cam Sensor on the 2004 Chrysler Sebring 2.4l I'm starting to think I was changing the wrong thing?

Answer
Hi Johnie,
It is on the rear of the cylinder head where the cam shaft's back end is located. It is round and has 2 screws that hold it in place and the surface of it looks like a pie cut in 8 slices. The plug has the three wires I described earlier.
Roland