2016 F150 2.7L 4Wd P025a
First post asking for help ever, please correct me if I missed something. Truck originally came in with engine stalling 10 - 15 seconds after initial start. Verified concern. Checked power and grounds to fuel pump control module located under truck bed by fuel tank. Found a lose connection at G401. Cleaned connection, tightened bolt and rechecked. All good, tested powers and grounds with a headligt bulb. Engine was still starting and dying just like before. I figured the bad ground could have damaged the FPCM and replaced it with a Factory part from the dealed. Engine started and died once again. The same P025A code is always present after cengine is first started. The FPM output from ECM pin 27 and the return to PCM pin 39 have been checked with a headlamp bulb for countinuity with the FPCM disconnected. I powered the pins on the ECM side (disconnected from the EM) and put the bulb on pins 3 and 7 on FPCM connector. Bulb lights up bright. The blue wire going from fuel pump relay has power to FPCM pin 1 when ever the key is on. It also lights up the headlamp bulb brightly. If I bypass the FPCM as per the diagnostic instructions (jump pins 1 to 5 and jump pins 8 to 4) the engine starts and runs just fine. The desired fuel pressure at idle is 72 psi and the actual is 107 psi with FPCM bypassed. The restraint control module is allowing the pump to run as seen on the data PID. This truck does not have a fuel inertia cutoff switch. The only thing that seemed odd to me is the fuel pump is drawing 11.2 amps while running with direct power at the pump. Most pumps I have come accros usually consume 6 to 8 amps. I could not find any spec on current draw. Any help would greatly be appreciated. Thanks in advanced.
Just a few thoughts from home on an "extra" day off: Are you clearing all DTC in every module before starting it? Have you tried the on-demand self-test in PCM before starting it? Will the fuel pump run through bi-directional control? Can you scope the square-waves on the control (FPC) and monitor (FPM) lines when it starts? Is it possible one of the jumper/bypass tests you ran, caused loose…
Yes, codes and KAM are reset every time code is set. The only code keeps coming back P025A. ECM is sending a 12v pulse out to FPCM, The pulse is also present at the FPCM connection. There is no return signal comming out of the FPCM. I have now replaced 2 FPCM with factory OE parts thinking I may have gotten a bad one. There is no return signal comming back to PCM. Fuel pump is not responding…
any chance the FPM circuit is shorted to ground?? You should be able to monitor Fuel pump command and Fuel pump monitor pids in the live data as well. The FPM duty cycle is a status message. 20% -This duty cycle indicates the fuel pump control module is receiving an invalid duty cycle from the PCM. 40% -This duty cycle indicates the fuel pump control module is receiving an invalid event…
The short to ground and power were checked with the headlamp bulb when the continuity tests were performed. Each leg was checked individualy for short or power. Key on engine off the duty cicle reads 75% while the engine is first started during the time it is running it drops to 35%. When the FPCM is bypassed as described above, the duty cycle reads as 80% as it should since it is reading an…
My previous post was related to the Fuel pump monitor DC not the Fuel pump command DC. the command DC is as follows 0-15% -- Invalid OFF duty cycle. (The fuel pump control module sends a 20% duty cycle signal on the fuel pump monitor (FPM) circuit. The fuel pump is OFF. ) 5-51% --Normal operation. (The fuel pump control module operates the fuel pump at the speed requested. FP duty cycle times…
Got it. I will do further checking tomorrow. And post the results. Thank you.
Sounds like you have had a very difficult time. I'm not sure if it will help but I'm attaching some known good files here in case it might help. They come out of our Ecoboost class and we captured on a different engine (2.0L Edge) so I can't say for sure that there won't be some difference. I do have a 3.5 Ecoboost that I could also give you some data on if it will help.
Hi Phil. So in your third known-good capture we see a 40% for duty cycle for FPM, but in Chris' info above he said 40% for FPM is a bad thing. Hmmmm.
50% is the pump full on,,, From a previous post, "5-51% --Normal operation. (The fuel pump control module operates the fuel pump at the speed requested. FP duty cycle times 2 equals pump speed % of full ON. For example, FP duty cycle equals 42%. 42 times 2 equals 84. Pump is run at 84% of full ON. The fuel pump control module sends a 60% duty cycle signal on FPM circuit. )"
I know what Cris said Albin, but Phil's known-good capture shows 40% on the FPM. So that's a contradiction. Perhaps the scope 40% duty cycle is what the scan-tool calls 60%. If one counts the 0v and the other count the 12v one would say 40% and the other would say 60%. But that's me guessing.
Hi Geoff, It's a negative duty cycle, so Phil's captures show about 40% positive duty cycle, or 60% negative duty cycle. The PID isn't specific, so it's easy to get confused. Sometimes the PID and negative duty cycle on a DVOM or scope don't match (the PID may say 40% and the circuit shows 60% negative), so the PIDs won't always match the published specs. In any case, I have other captures of…
Great! Thanks for the clarification Tim. I had my suspicions... :-)
This information is for Electronic returnless fuel systems for the 2016 MY, there are some other differences year to year and system to system. Its important to realize the FPDM only knows 1 language, Duty Cycles. The % shown does not mean the actual command of pump output but a messages to and from the FPDM.
That's correct. Here's the proof: scanshare.io/share/1vY61Q6P… (The decimal point error is a Snap On problem.) We can't always see the "feedback" in terms of low side pressure since not all Ford direct injections systems have a sensor on the low side. Here is one that does not: scanshare.io/share/gurn_HDM… We can only guess that the low side pressure went up under…
"Fuel pump monitor barely moves regardless of the command so I think it is simply a code setting signal, not a feedback." That's what I had read somewhere else, and was surprised when Chris posted all those ranges. (to confuse me...LOL)
I really appreciate all the help and input I have received. This morning the customer showed up with a wrecker and said he would be taking it to the dealership since it was still under warranty. Truck has 38k miles on it. I requested the customer update me on their findings (really good customer, I know he will get back to me). So I will post a fix sometime next week. I would have suspected the…
So if this setup is the same as the 05 mustang which it looks like it is on the wiring diagram the ECM is suppose to put out voltage on the FCM wire. The FPCM should then ground it to create a feedback duty cycle. We had a bad pcm on this one. Curious to hear what the customer will have to say after he gets back to you.
Two circuits, two separate signals. FPC is output from the pcm. FPM is the return status signal output from the FPCM. You could even try a fused jumper between the two (FPC and FPM) to see if the signal sent from the PCM returns on the monitor. I have used this testing with Alternators as well