mustang_bluemustle

I have a 1999 Mustang GT. I recently got the engine light on with code P0340. I have been reading on other posts that this code usually indicates a faulty alternator. I have replaced the crankshaft & camshaft position sensors just to make sure is not one of those sensors. So, what I most likely need is an alternator. Now my question is if there is something in the alternator that fails causing this engine code. My alternator is charging at around 13.7-13.8 volts. I dont want to spend $200 on a new alternator. Anyone know of a cheaper way to fix this engine code?

school boy

clear the codes. if you replaced the cam position sencors then it might take a bit for the codes to clear automaticly. any parts store can clear them, but if they come back then the alternator is probly the cause

cliffyk

The only way to fully test for a noisy (electrically "noisy" which is what messes up the cam sensor signal) generator is with an oscilloscope. If the generator is the source there is of course no "cheaper" way to fix it.

Here is the procedure for testing the CMP sensor...

mustang_bluemustle

I cleared the engine light a few times but the code is still coming back. I have an alternator from a 96 Mustang GT that I just sold and Im wondering if it would fit my 99. Has anyone tried doing this or know if they are interchangeable? Thank you for your help.