01 Dodge Caravan 3.3l No start

No Start because of Camshaft Signal cuts out after a few seconds of cranking the engine. Hooked up DVOM 5v on signal when KOEO. Start cranking and voltage drops to less than a volt. With DVOM it should match CKP signal of 3.5v on average. I know you need a scope to really look a square wave form. So I bought a scope and hooked it up I can see the wave form on CKP sensor signal, but CMP Signal shows up then drops off flat line. Check 8 volt supply and it's 9v all the time.

Spec for supply voltage 7.5v to 9.1v, so no problem there.

With the sensor disconnected make sure the 5v on the signal wire is stable and does not disappear while cranking. If it does disappear check the wiring and (at) the pcm connecter.

With 5v present on the signal wire during cranking you may want to look closer at the sensor itself and the reluctor.


Is there a backstory to this?

Here's the back story, came to check a no start after new/used engine has been installed. Found out the engine was from 2007 which is a problem since Cam Gears don't match to 2001 thought that was the problem changed the timing set to the OE for 2001 New set was installed still no change. I thought since the magnetic pick-ups were incorrect that's why the reading was off on the sensor. Before I got to the vehicle the guy bought a new computer changed Cam and Crank sensors. I'm just trying to figure out someone else's mess. I seen this site you guys know what's up I figured its worth a shot. I appreciate your time in this matter.

Was the "new" pcm programmed accordingly? Is the immobilizer matched?

Is the crank reluctor part of the fly wheel on these? It's been a while since I've seen one of those engines, but I recall more than one engine swap ending ending in a crank no start and the mech having to pull the engine again to change the flywheel.
You could scope cam and crank and compare to a known good of the correct year engine. Or even find a known good cam and crank pattern for each of the engines and compare the notches in the crank signal pattern.

Yes the new PCM was flashed to the Vehicle. And I asked why the PCM was replaced I was advised that when the other mechanic was trying to diagnose the no start he was using a test light on the fuel injector and a popping sound was made like a fuse was blown that's why the PCM was replaced it just keeps getting better and better. I was double checking the voltage like you told me and I did find something interesting. I have a JDiag P200 and I had it on Smart Meter with auto select and it started on 5v KOEO then when I Cranked it the Meter Switch to OHM's and was reading 78.0 OHM's when it should be reading Voltage. I tested the the Crank Sensor and it stayed on voltage the whole time. I didn't catch this before because I was using a basic DVOM. Is there anything else that could have gotten damaged like the FCM? I checked all the wires going to PCM to CMP and there OHM reading were .04. And I did check the 5v Ref while cranking with sensor unplugged and it stayed at 5v. Here is some pictures

#1Cam signal and #2Crank signal. Thank for the help.

Sorry pics aren't best quality