2016 F150 P0335
If anyone is familiar with this vehicle(or similar) Im trying to find out what the reading(V) should be on the CKP signal wire with the connector unplugged, KOEO. (not cranking)
I am not looking for diagnostic advice or help at this point. That may come later.
I am looking for a specific reading. I cannot find that info. There is an IDfix thread that says the reading should be source voltage,however I have not been able to confirm that in anyway.
I currently have 5v on that wire,KOEO (not cranking)
If memory serves, there should be 5 volts on the signal wire. It is a pull down signal.
Todd- Appreciate the input. This is the photo in the IDfix article and where I am confused. If what you say is correct, then they are definitely leading techs down the wrong path:
How can Vsig be 12 volts if Vref is 5 volts??? I am with you - the diagram is bogus.
There are some VW sensors that have a 5V power supply, ground, and the signal is a 12V square wave. The ECM sends 12V on the signal wire and the sensor toggles it. Not sure about this Ford though.
Perhaps it is a bias voltage used for fault detection? 12v unplugged. Just bouncing ideas around.
Hi Rudy, I can recall the CKP sensors were 2 wire on these. Have you confirmed it is a 2 wire or a 3 wire?
Mr. Mestaz (Rudy); Good evening Sir, i hope all is well. Searching within Diag.net I was able to find a waveform posted by Ray which could be of assistance. diag.net/msg/m1lkqm39s8… In this waveform capture you see the Camshaft Sensors are “Full Voltage Sensors'. I hope this helps,
Jonathan- Appreciate the input man. Im actually chasing down a crank sensor fault and if Im reading your link correctly, it is a 0-5v wave.
Hi Rudy, I suggest you isolate the wires and then load test them to determine if it is wiring (which I suspect) or the PCM has an issue. An Ohm test is not reliable. A halogen bulb and some leads with a 12V power source are a method I use most of the time. Are there any PATS related issues? Often a full code scan may not give all the information or codes. Okay, I offered troubleshooting…
Hi Rudy, Like any Ford crank sensor, you should see a consistent 5V square wave pattern. The trick is to watch for deviations and shifting. I've run across several engines where the balancer bolt was not torqued properly. The result was the trigger wheel/ reluctor had the keyway are hammered and it was shifting/ ratcheting with crankshaft acceleration and deceleration. On two of them I found…
I dont know for certain what the bias is on that particular YMM. However if I saw 5v I would be happy with it. Maybe that would get me in trouble.
Hi Rudy, I talked to a local Ford tech I know and he said the CKP signal wire will show very low voltage when disconnected from the CKP with the key on, there is no set published value that he knows of. It is basically a "monitor voltage" (mV's) the PCM sends to conform wire integrity and the sensor is present. Other than that it supplies the digital signal to the PCM when the engine is…
Just sent you an email as well. It could very well be 12 volts KOEO. I've also seen 5 volts on that circuit. It depends upon the calibration. I've seen this many times on Fords. Are you getting any voltage reading at all? BTW, the Ford PPT (JD) doesn't for your code mention any test for this particular circuit voltage, which is pretty standard for them on most of their vehicles. All they have…
Ok so back story on whats going on here: (I apologize for not posting this earlier ,Id hope to figure it out before now) Vehicle was towed in , died while driving, crank /no start, P0335 stored(no other codes) Quick scan data pull showed no rpm reading. I lifted the truck to inspect it and found the ckp harness runs under the turbo and melted(heat shield was missing) I cut off about 9 inches…
Hi Rudy, Clear the memory and retest, Ford is bad about retaining memory and the ECM ‘thinks’ it has a problem when it actually does not. A 5V sensor circuit does not carry enough Amperage to burn a wire, that is the main reason why they use 5V low Amp in many computers. Generally the wire burn damage is from another outside source. If it still shows 5V on 2 of the wires it is likely a damaged…
Glenn- Yeah I tried a kam reset. Same deal. The wires weren't burned from current, they sit ½ away from the hot side of the turbo. Even the heat sheathing melted. There was supposed to be a metal heat shield covering the whole set-up, but some time in this trucks life it was removed and not replaced.
Rudy, that harness that melted--is there a wire in that bundle that is “carrying” 12 volts?
Mike- Well that's the dilemma. The harness that melted only contains the 3 wires for the ckp sensor( they fused together) and I don't know if the signal wire goes to 12v when open or not.
Hi Rudy, A couple of minutes ago, I discussed the problem with my buddy at Ford, he is checking into it, but said the PCM is highly unlikely. He suggested to confirm the exact (color and number) wires to the exact pin number of the repair connector. Connector views on the sensors and harness side have been know to be printed backwards in some service date. Match the existing harness wire colors…
I couldn't agree more Glenn--even if I have to buy directly from the dealer (if I can't get the part form a Motorcraft warehouse) that's where I buy it.
Glenn- I was certain my repair is correct, however I went ahead and cut it off and I am getting the same readings from the bare wires. This is why I suspect the wires may be shorted together somewhere. Still,If I knew what my signal wire should read unplugged,it would help give me direction. The sensor in the NAPA box looked identical to the one I pulled from the truck, right down to the…
I sent the copies I have to your email. Hope it helps you
Hi Rudy, For now, take the cam sensor itself out of the equation. Given the circumstances of the harness being burnt, it is really favoring the ECM has suffered internal damage. Were their other wires in the burnt area of the damaged harness or was it strictly the CKP breakout harness?
I'm sure you are avoiding cutting the CKP wire at the PCM to eliminate/verify the harness-short possibility, so try this. With a meter on the VREF, touch that ckt with a grounded test lamp. Note the reading. (I would suspect it to drop from 5V to around 4 or so). Now run that same test on CKP. If that drops to exactly the same reading as VREF, they are shorted together. If that drops to 0V, it…
Oooooohhhh Big Geoff swoops in with the diag tips!! Will do loco, sounds like a good way to go. Youre right,Im putting off cutting the wire until the last resort. I like your thinking!
Hi Rudy, Geoff has some good tips. He is accustom to working on some very unusual problems where he is at.
Might need one or two different lower amp test lights, in case VREF drops to zero also. It shouldn't though.
Id like some clarification. Is it a valid test to run a magnet or piece of metal in front of these hall effect ckp sensors and expect to see a response on my scope? Obviously I wouldn't see a square wave, but maybe just a bump(or reduction) in voltage as the sensor reacts to the metallic piece? Or is not a valid way to check the sensor?
Hi Rudy, It is not a valid measured method, but it is a quick test to run a pocket screwdriver or similar metal tool past the sensor tip. Anything that breaks the magnet field produces a signal from the sensor if all wires are connected and correct. It should show up on a scope with the key on and engine off and the sensor back probed. Here is a You Tube video that may help: How to Bench…
4th sensor was the charm! I started to wonder why I wasnt getting any response when I passed a piece of metal in front of the previous sensors.(as seen on my scope) I assumed it was because there was an issue with my signal wire. Using Geoffs method(thanks vato, I owe you a taco!) I ruled out a short in the harness. I started to think….. maybe….just maybe I have a run of bad sensors. So we…