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EricFromCT
EricFromCT, Ford Technician
Category: Ford
Satisfied Customers: 3523
Experience:  20 years dealership exp., ASE A1-A9 L1 L2, Ford Lincoln Mercury Senior Master, Diesel Certified
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2004 f-150 5.4 p0345

Customer Question

2004 f-150 5.4 p0345
Submitted: 1 year ago.
Category: Ford
Expert:  EricFromCT replied 1 year ago.

Hi. Do you know if you have the original alternator in the truck?

Customer: replied 1 year ago.
this is not my truck. It is a customers, first time working on it. ( i work a small shop on my own ) it looks to be the factor unit.
Expert:  EricFromCT replied 1 year ago.

Ok. The reason I ask is because Ford has had out a service bulletin that states a bad diode in the factory alternator can cause that code to set.

Customer: replied 1 year ago.
does it set code and run fine or does it set code and give it a running condition? because it also runs poorly.
after it has been running a few mins. it idles ruff and has no power wants to stall and does then can be hard start.
Expert:  EricFromCT replied 1 year ago.

The message does not indicate it running rough. Plus I also would think you could disconnect the alternator connector and see if that changes anything.

Expert:  EricFromCT replied 1 year ago.

p0345 indicates that the pcm is not getting the signal from the cam sensor on bank 2. FIrst thing to do would be measure the resistance of the cam sensor on the drivers side. Should be 300-425 ohms.

Customer: replied 1 year ago.
has a new sensor installed. do you still want me to ohm it? if so, ohm just the sensor with it unplugged?
Expert:  EricFromCT replied 1 year ago.

You probably still should measure it. WIth the connector unplugged.

Customer: replied 1 year ago.
1st: cleared codes, completely disconnect the alt, started let run set p0345 (no cel). idles little ruff.
2nd: omh both sensors installed & uninstalled. using the 2k scale the new sensor was .279 installed .283
uninstalled. the factory sensor .324 in & out, so i reinstalled the oem sensor.
3rd: old sensor in, alt disconnect, clear codes and start. idles poorly and sets p0345 with no cel. if i let it run long enough or stall it will set code with cel.
4th connect alt back up clear codes start let idle p0345
Expert:  EricFromCT replied 1 year ago.

Since the sensor is good, and you have a p0345 circuit code you need to check the wiring from the sensor to the PCM. If you have a scan tool that can read the cam sensor you could compare its reading to the bank 1 sensor. Then most likely start checking wires, with a resistance check then a load test if needed.

Customer: replied 1 year ago.
i have a snap on red brick i'll try it. but also is there a pin at the ecm,so that i can ohm the wire (ecm to sensor or is it not a direct run?)
Expert:  EricFromCT replied 1 year ago.

The grey/red wire at the sensor should have 5 volts to it from the pcm. The orange wire goes straight to the pcm on pin 44 of one of the connectors.

Customer: replied 1 year ago.
tomorrow when i get work i will ..... KOEO check voltage to sensor with volt meter grounded to battery pos to gray/red
wire. and ohm the orange. do you know which of the 3 ecm harness plugs it is in? left middle or right looking at it?
Expert:  EricFromCT replied 1 year ago.

Should be the connector furthest to the passenger side. KOEO negative meter probe on battery negative and positive meter probe on grey/red wire

Customer: replied 1 year ago.
let you know something tomorrow thanks
Expert:  EricFromCT replied 1 year ago.

ok

Customer: replied 1 year ago.
i did not use the scanner today while trouble shooting. KOEO test only.
1st: check for voltage at cam sensor plug. no voltage (0.01 v) so while i'm at it i probe the gray wire on bank 1
also no voltage.
2nd: checked orange wire with ohm meter. unplugged harness from ecm and probed pin 44 to sensor plug ''ok''
also probed pin 45 green to sensor bk1 ''ok''
3rd: went back to double check voltage at the gray wires now showing 5.00 v then i realized the harness was still unplugged
form ecm. plug the harness into ecm and the power goes away. also when i'm plugging the harness in, it makes a noise near the throttle body. sounds like an actuator or a motor. (possible throttle controller but throttle butter fly doesn't move)
unplug it voltage comes back.. plug it in losses power..unplug in comes back. also does the same with bk1 sensor.
Expert:  EricFromCT replied 1 year ago.

From what you describe sounds like something is shorting the power circuit. Did you disconnect the throttle body and see what the voltage does?

Customer: replied 1 year ago.
i did try to unplug it to see what would happen, but wasn't able to get it to unlock and unplug. got the red safety lock out the way
hard time getting to the connector lock, so i gave it a brake
and figured i give you an update before going farther. i'll get it unplugged tomorrow and see what happens and i'll touch base with you tomorrow with update.
Expert:  EricFromCT replied 1 year ago.

alright. Sounds good.

Customer: replied 1 year ago.
Unplugged the throttle controller and tps. Removed thottle body to get more room. The noise is a actuator on rear of upper intake plenum controlling a valve inside plenum. Anyway I removed the swing lock off ecm harness plug to make it easier to play with.
I've been playing around with plugging and unplugging the harness in. I can get that actuator to work and move to where it should be without losing voltage, move the plug a little and lose voltage.I can get it to lose voltage without the actuator working.
so I don't think it's the problem. I tried to plug the harness at ecm in at different slight angles to try to get the rows of pins to hit before the others. I could be wrong, but it seems like when I get the top row(s) (pins 1-17 18-33) (used 9-17 24-33) to make contact I lose voltage,but not sure. It is killing volt to both sensors. (Some extra info from before our talking. When I had it running and it wanted to stall, if I unplugged bk2 sensor it would run different (better) and it will give a p0021 &p0011) not understanding why there is no power to sensor and not setting code until unplugged, and also runs diff unplugged.
Expert:  EricFromCT replied 1 year ago.

The code indicates that the computer is not seeing the signal from the bank 2 cam sensor. Looking further into it there may not be voltage on the grey red wire. The sensor is variable reluctance and creates its own ac voltage to the pcm. You can check at the pcm wires while cranking if there is an ac signal of over .25volts.

Also check the oil level.

Also I can send you the pinpoint steps if you would like.

Customer: replied 1 year ago.
send me what ever you can need to know pin #s. I will have to look and see what I have for an ac meter. when I probe the gray wire I'm guessing I need it plugged in to ecm and back probe the harness plug. But I don't understand why it show 5.0 volts when I plug into ecm, whether it there or it goes away what's with the 5 v I'm getting??
Expert:  EricFromCT replied 1 year ago.

That is odd. There may be 2 wires shorted together. One being the cam sensor wire. I think maybe that wire is shorted in the harness to a wire that is 5 volts. Which is the vref circuit to most all sensors.

Expert:  EricFromCT replied 1 year ago.

CLICK HERE for link to p0345 diag

Customer: replied 1 year ago.
Got everything printed out, have been skimming over it to prep for the trouble shooting. I would like to tell you everything I've done before contacting you. I didn't bring it up because it hasn't given any of these issues (just p0345) since the one time.
The first time I ever run the engine was pulling the truck into shop. CEL was on. It started up fine and seem to run fine, after a min or two it start running poorly.After getting into shop it started to really run bad and making noise. I could tell the noise was
coming from t-chain, so I shut it off. Scan and get a pile of codes p0011, p0021,o0175,p0345,p2106,p0171,p0172.p0340. I suspected cam phasers. So the 1st thing I did was pull oil switch put in oil gauge. Cold start engine, 75psi then it dropped to 0 then noise. I immediatley shut down. Checked oil and was extremely low. filled with oil. and restarted. Started 75psi kept on running holding 75psi. Cleared codes restarted set codes p0021, p0345. several times. I then changed the oil and replaced the VVT/VCT solenoid and cam sensor (both on Bk2). Started engine 75psi No codes. After a few mins it started run little ruff oil pressure 70/75psi. took it for drive around neighbor hood. run like crap. set p0345. let the engine come up to temp and run
little longer to get oil good and hot.Now it idles poorly and wants to stall and does. Unplug sensor it smooths out some and will idle. Idle betweem 500/600 rpm hot oil around 20/25 psi. If I idle it up to its factory 750/800 rpm it has 30psi. It doesn't make all the noise t-chain/ phasers now either since I corrected the oil issue. I checked the crank for crank walk. All I did was measure between the timing cover and back of balancer. I'm coming up with an average of 15 thousand walk. Don't know
the max amount, but seems to holding enough oil press, and making no noise. just keeps setting a p0345 with/without CEL.
That's how I got to you with the p0345
Customer: replied 1 year ago.
Got to dr13 hooked my +pos plugged into sensor plug gray/red wire -neg on battery turn on key get 5.00v . It asks if volt is less than 1v. Says I have to repair the short. I'm guessing to go farther and to make what i'm doing easier, I will need the view of the ecm plug, with pin out chart and wire color schematic. and I guess the diagram of this circuit. Would you have any idea where I might want to start. What else shares this wire ? Something else while I was messing with it. As we already know if i unplug the left ecm plug i get my 5v .. plug it in goes away 0.01v. So with it still plugged I get 0.01v. I unplug the center harness plug and it jumps to 9.88v then also unplug the right plug jumps to 11.50v plug in the center drops to 0.01 then plug in the right 0.02v. Am I just messing to much or is what it's doing normal when unplugging the harness. I just thought this was strange if it is not a powered wire and is shorted. (and to what)
Customer: replied 1 year ago.
still there? are we finished?
Expert:  EricFromCT replied 1 year ago.

Since it does not seem like something simple, you are going to have to follow the pinpoint steps.

CLICK HERE for pcm connector 175e

CLICK HERE for cam sensor wiring diagram

These should help.

Customer: replied 1 year ago.
please bare with me i'm a little rusty on my electrical trouble shooting and i get a little intimidated. the connector view only came with circuit function list 1-38. no list for rest of connector.looking at the engine ignition diagram it looks like 44 orange is a straight run and the gray/red pin 58 splices to sensor 1&2 then goes to ecm. if the short was in the harness could i just by-pass the whole harness? if the orange is a feed to the sensor and the gray is signal return, is the orange a 5v referance from ecm?
i checked with ohm meter from these two pins to all others in connector to see what would happen ...nothing. if i go to the pins on ecm with key on i get 0.01v is it possible that the problem is not in harness going to sensors because i get the same answers on both sensors.
Customer: replied 1 year ago.
I'm sorry but I believe I need to correct my self.I double checked myself this morning. checking at the plug I am showing a short between pin 58 gray/red signal return and pin #57. I'm getting the 5v from there to pin 58. but my pin list stops 38 so I don't know what that is.
Customer: replied 1 year ago.
hey Eric where you able to get rest of print out?
Expert:  EricFromCT replied 1 year ago.

If you are using your ohm meter the circuit needs to be powered off and you will be measuring in ohms, not volts. you may be on to something if those wires are shorted. Let me check back at the wiring and get back to you.

Expert:  EricFromCT replied 1 year ago.

CLICK HERE for the rest of the pin terminals.

Customer: replied 1 year ago.
I'm using volts with the key on and ohms key off. I have checked both ways. If I check it at pin 57 to 44 & 45 with sensors plugged in I get a short. Unplug sensors it goes away. then I jump over to pin 58 it comes back. So I'm taking that's where it's coming from. Pin chart: pin 57 is circuit 351 BN/WH Reference voltage. I would need a circuit print out for that circuit. But before I go digging through the entire harness looking for the short. Could I cut the gray/red pin 58 on harness side of ecm plug and harness side at cam sensors and splice in a new wire? Go from sensor to sensor then to the ecm?
Expert:  EricFromCT replied 1 year ago.

Yes. Just overlay a wire over suspect circuits for now and see if you get different results.

Customer: replied 1 year ago.
Ok so I clipped the gray/red wire at both cam sensors and behind the ecm plug. ran a wire from sensor to sensor over to ecm.
started engine still runs poorly and shot out a pile of codes. p0113 air intake temp..... p0193 fuel rail pressure....p0198 oil temp....p0345 cam sensor..... p1289 cylinder head temp sensor Now what??
Customer: replied 1 year ago.
Eric I know I only put in for a $28 question and neither one of us thought it would end up being the problem it is being.
But there will be a bonus coming to you if you can help get this done. But I need a quicker response time than every few days.
(other than on weekends) the owner is being very understanding but this is getting drawn out. I really need to know what my next step is? thanks
Expert:  EricFromCT replied 1 year ago.

Sorry. I have been having issues getting online lately. I will open the question back up to other experts as someone may have a better idea and be able to be online more to help. THank you.

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