I am not getting voltage to the cam sensors on my 2007 expedition with 5.4l. Wires check out good all the way back to the pcm. No voltage and throw cam position sensor codes. All fuses are good. Im thinking pcm maybe? Before i spend that cash for a computer id like to be sure tgats what the problem is. Previous owner spliced in a new connector on passenger side sensor. I need to verify it was wired correctly too. Looks like he didnt ground the shielding wire too.


Help!!

 

I looked in my 2007 Expedition/Navigator Workshop Manual wiring diagram and could see that:
Each cam sensor has it's own circuit. Each circuit goes from the PCM to and through the cam sensors and back to the PCM. The circuit shows the shielded wiring is supposed to be grounded. Also the same shielded wire circuit is spliced to the crankshaft position sensor shielded wire.
I think this is a control circuit that uses 5 volts. I would not send 12 volts through that circuit into the PCM - it will fry it.
Looks like you could unplug the sensor and use a ohm meter to check continuity and resistance on the sensor. I don't know the resistance value but both of your sensors should be similar.

Richard

 

I did a little reading to find the resistance value for the cam position sensors. I did not find the correct value - yet.
Those trouble codes indicate both circuits for the cam positions sensors could have an intermittent problem. Also all 4 codes say that a weak battery or starting circuit problem could be the cause.
Sounds like you should double check some of the work that was done during the engine repairs.

I think sensor 1 is located on bank 1 and sensor 2 is located on bank 2.
Looks like sensor 1 has a violet wire going from the PCM to the sensor and a brown/blue wire returning to the PCM.
Sensor 2 has a brown wire going from the PCM to the sensor and a green/violet returning to the PCM.
The PCM grounds the circuit returning wire inside using a diode.

I think the engine would run without the shielded wire grounded properly. However I think it is best to fix those shields.

Richard

 

You most likely have a base engine timing problem. The cam sensors generate an AC voltage to the PCM. If the PCM sends voltage to the sensors its only at KOEO to test the integrity of the wiring. The descriptions for those codes are not very good. Are there any other symptoms with the engine?

 

Other symptoms are hard start and misfire and no power when hitting the gas real hard. Shouldnt there be a 5 volt dc signal to the sensor? I have continuity back to pcm on all wires. Nothing is shorted to ground either. Battery is good at over 12.5 volts sitting off.

 

No the pcm doesn't send 5v reference to those sensors. They are VR sensors and generate a AC voltage that the pcm reads for the cam position. You need to verify base cam timing before anything else

 

How do i check base cam timing? Pull valve cover and look at phazers?

 

Also its a fresh rebuild(previous owners) and ran fine for the first 2000 miles.

 

Do the codes come right back after clearing them? If it takes a while you can monitor the VCT error pids if you have access to a scan tool. Maybe try unplugging the alternator to rule out RFI. Who rebuilt the engine?

 

Codes come back right away. It takes three cranks to start and then stumbles a bit before leveling out. I unplugged the alternator, and it made it worse. Really stumbled when hitting the gas. I pulled the valve cover tonight and timing marks are good uo top at the cams. Phasers look new. No varnish at all and still has the paint mark on the chain and sprocket. Chain has a tiny bit of slack, but not making any noise. I dont have access to scan tool. It really takes a long time to start when cold, butvthen gets to idle and sounds good. Big hesitation on throttle response though. If you feather the pedal it revs right up and runs fine. Im at a loss. Im getting errors on both sensors. Ive got a new pcm, but dont want to shell out $250 to program the keys for nothing. I found a plugged vacuum line today on the passenger side near radiator. Looks like only the bottom end was built. There was a lot of sludge and varnish under valve cover. What next?<img src="https://cimg3.ibsrv.net/gimg/www.ford-trucks.com-vbulletin/2000x1124/20180727_192445_ec89679125283222e1e909d4b4be6ad0bd 1597be.jpg"/>

 

I think it's out of time. Not sure how it ran for 2k miles then now this but the only way to know for sure is pull the timing cover and re time it. What do the fingers on the phasers look like? Are they oem or aftermarket phasers? I have seen the tone wheel move on the phasers and cause cam codes too. If any of the fingers are bent that will cause the codes as well.

 

nd48463,
I don't know what could be the problem with that engine either. 70f100longbed seems to know more than I do about how the sensors work.
I have the 2007 Expedition/Navigators service manuals. I have a 2007 Navigator. If I can look anything up for you let me know.

I agree it would be great to recheck the base timing but also can see that it ran normal for quite a while.
I am watching this post daily and hope you solve the problem.
Richard

 

I finally started really digging in yesterday and opened up the timing cover after removing everything in front of the motor. Timing was goid. Clean and tight. I just happened to be watching some youtube videos with tech Makuloco and he was showing the pulsator tone ring for the crank and mentioned to make sure you install correctly. I looked down and pulled mine off and found it backwards!!! All the teeth were chewed up from the chain hitting it!!! Must have worn to the point where the crank position was not reading consistently throwing the codes. Cheap part,but lots of work to get to it. I ordered all new cam and crank sensors along with some ford vct solenoids. Hopefully this does it. I couldnt figure out where the plugged vaccum line goes yet, but ill start putting it back together tomorow. Will update as i go.

 

Glad you found it. Normally when those are backwards the teeth gets chewed up instantly and can sometimes break the chain. I would still verify the cam timing just be make sure you dont have to go back in. If your expedition is 2wd that plugged vac line is for the not present 4wd hubs.

 

Put it back together tonight. Started right up and settled in nicely. Lots of power, no codes!!! Timing wascset properly. I replaced plugs. Vcts, cam sensors and crank sensor. Fresh oil change and rock and roll!! It is a 4wd and i think it engages so probably not that. I noticed a tranny leak now too so I will have to check 9n that this weekend.

thanks to everyone who helped along the way!