Autonerdz forums

Tom,
In your classes and on the website, you talk about Ford Camshaft Position Sensor synchronization.  There are pictures of how it appears with the Fluke 97 (I believe) on the website.  Do you have any pictures as it appears with the Picoscope and can you discuss this a little for people that have never synchronized one?  Thanks, Ziggee.

Hi Tom,

The above waves show the HALL switch type of CAM sensor in relation to the VRS CRANK sensor.
Any chance that you can show a relationship with the VRS CRANK sensor and the VRS CAM sensor as used on some Fords, if you have one in your archives that is ?

Thanks Tom, I have not encountered one to use the PICO scope on, I did some reading and discovered that the PCM reads the signal where the wave is going negative to a point just below the 0 line.
just wondered why not at the 0 line.

Hi everyone,
I was wondering if you can just use another scope channel on secondary ignition number one or number five instead of pulling a plug to confirm compression on one or five being that the computer maintains spark firing order timed off the missing tooth on crank  even without a cam signal present at all       God forbid I wouldnt want to do things the hard way!!!!      I realize the timing would float around some so it cant be used as a reference point for actually setting the sensor but it would be a quicker way of getting the up or down  direction right on the cam sensor would it not???????

hail the King.
thanks never done it but was wondering and there you have it!!!!!also that uses multistrike cool!

More on hook up logistics when working with floating ground VR sensors:

Incorrect scope hook up can create problems with the
vehicle or even cause a no start condition. Ford EDIS cam
sync is a great example. The CKP is a floater and the CMP
is either a hall effect or a non-floating VRS. The common
mistake is to hook a channel input and ground across the
CKP. That works fine if that is the only channel you intend
to use and you will get an accurate representation of the
CKP amplitude. But that doesn't help you sync. You have to
use another channel on the CMP. But your scope is now
grounded to something generating voltage ;-p If you use
another channel, weird things are going to happen. This is
because, on most scopes, the channels share that common
ground. The CKP voltage will cross feed through the scope
to someplace it shouldn't be.

The correct method is to reference all channels to vehicle
ground and back probe only one of the CKP wires with your
scope channel input. You must choose the correct wire so
your waveform is right side up to get your degree count
right. The other wire provides a pattern that is inverted
and will throw off your crank degree count. Hooking up this
way will allow you to use multiple channels with no
problems. However, it will make the CKP waveform reduced in
true peak to peak amplitude and it will appear to 'float'
above the ground line when the scope is DC coupled. Neither
of these issues is a problem if you are looking to sync the
CKP/CMP.

If you are looking to measure the CKP peak to peak volts,
however, this will not do. You will have to dedicate one
channel to this task and hook channel signal and ground
across the sensor to get this information. No other
channels should be deployed.

So, how you hook up depends on the information you want.

Non floating sensors like the EDIS VRS CMP have the signal
present on only one of the wires and display accurate peak
to peak results with the scope referenced to vehicle
ground. So, these do not require a separate hook up to get
this information.

Hi Danny,

I don't have much Northstar stuff but I'm sure someone does.   

Tom here is an ford 5.4  3 valve with variable cam timing.  I haven't figured out what fords logic was in where they placed this one. Those with vct  will have the number of signals equal to the number of cylinders on the bank plus one in one full revolution of the cam or 2 revolutions of the crank.  The 2.0 four cylinder z tech will have a signal like this v8 .  Four cylinders plus one equal to 5 signals. On the z tech the first wave will fall at about 22 degrees atc for #1 and #4. The set with 3 waves will be at tdc compression for #1 and the set with 2 waves will be at tdc compression for #4. That seems to go right along with the other ford vrs cam sensors being at 22 degrees atc but this v8  seems to not go along with that logic. The second wave in the set of three is close.  This cam is installed quite a bit advanced and the second wave in the set of three might come out right when the cam is retarded to where the bottom timing is straight up. It's a sohc motor and it's advanced I assume because they are using the cam as an egr in the retarded position and to move the torque curve in the advanced position so it's kind of dual purpose.