I just found this excellent video by Paul Danner about troubleshooting and fixing a bad camshaft position synchronizer (CMP
) on a Taurus with the 3.0L Vulcan OHV
engine. While not all of you have scan tools like he does, it provides an excellent demonstration and description of what's going on with the failed sensor. He also shows the basic replacement procedure and the alignment with a scan tool (which is the most accurate way to align the new shaft). As usual with Paul, his diagnostic flow was excellent.
I will add the reason there is no diagnostic trouble code (DTC
) set is because the PCM
does not run the CMP
fault monitor above 2500 RPM
. Since the sensor usually starts glitching above 3000 RPM
, the computer will ignore the fault and no trouble codes will be recorded.
Notice how the bad shaft had bearing dust, was wobbly, and squeaked when he turned it. Remember this shaft also drives your oil pump, so if it seizes so will your engine soon thereafter. If yours is bad, make sure you buy the Motorcraft replacement part since others are inferior. Make alignment marks like he did, and make sure the new sensor end up in the same position as the old one (taking before/after pictures is recommended).
I also wanted to correct the proper tooth position he mentioned in the video. He actually hooked up to the crankshaft signal backwards, so the signal on his scope is inverted. The proper alignment is so the CMP
crosses 0 volts at 0-30º ATDC
, or between the 7th and 10th peak after the missing tooth. With the inverted signal, he should have been shooting for the 8th peak instead of the 9th. The 9th is still within the acceptable range, however.
Those of you without a scope will have to buy the alignment tool and find TDC
#1 by hand for proper alignment. Make sure you buy the correct tool for your sensor type (3-pin Hall effect or 2-pin VRS
). You can reset the KAM
by removing the battery cable if you don't have a scan tool (removing the cable before starting work is advised).