Error Code P068A on Coyote Gen 3

[GTME96]

Hello forum. This is my first post. I've read a lot over the last couple of years and had plenty of questions answered without having to ask. But I've run into a problem I haven't seen here and hope this community can help. After completing my build (Mk IV Roadster with Coyote Gen 3 Engine), I took the car out on its maiden voyage last weekend. No issues driving to a restaurant. But it stalled almost immediately when I left to go home. I was able to get it home, but it stalled every hundred feet or so. I bought a code reader and the engine is sending code P068A - ECM/PCM Power Relay De-Energized Performance Too Early. I don't know if this is causing the engine to shut down, or if this code is being triggered because the engine shuts down.

It does not stall at idle. It revs in neutral to 3000 rpms. Fuel pressure holds steady at 65 psi at idle. Aeromotive in tank fuel pump delivers 340 lph.

I've contacted Ford Performance. So far, they suggested to check the battery and grounds. Battery tests fine with 86% charge. It is a Duralast with 550 cold cranking amps at 0F. All grounds are still secure.

Weird thing is that I made my first go-kart test drive in August of last year. Since then, I've done dozens of test drives and put 90 miles on the car. But it was all in my neighborhood and never above ~30 mph. In that time, I've never had a problem with the engine. Then this happened the first time I got it up to ~50 mph.

I've also installed a Digital Guard Dawg Keyless Push Button start system. But, again, that was installed in May and has been tested many times since then with no issues.

Any suggestions on what could be wrong or how to troubleshoot this?

Thanks in advance!

[edwardb]

Are you running the stock tune or has it been custom tuned? My Gen 3, admittedly an early one when they first came out, ran OK for low speed go-kart runs. But when finished and going out for "real" drives it was not happy. Numerous codes, etc. Never actually shut down but bucked, cut-out at certain RPM's etc. Custom tune fixed it. 9,000+ miles on it now. Runs great and hasn't thrown a code since tuned.

[GTME96]

Thanks for the reply. It is a stock tune. I was considering a custom tune, but have not done that yet. I expected it would be fine with the stock tune and that a custom tune would only optimize performance and maybe fuel efficiency. But that might be the fix. I haven't found any other smoking gun yet.

[BEAR-AvHistory]

From day one it was not uncommon for the Coyote's to require a tune. The and the air flow sensor with the intake pipe installed 180 degrees out of alignment.

[michael everson]

A custom tune is basically mandatory on a GEN 3 and newer coyote.
Mike

[65 Cobra Dude]

What they said plus a bit. I had the same issue and tracked it to shutting off my battery main cutoff switch (no keep alive yet) too soon not allowing the computer the 5 or so seconds to shut down properly. My fix was to wait 10 seconds after shutting off ignition before shutting of main battery switch. I then installed a 10 amp automatic circuit breaker across the cut off switch so there was always 10 amps of power which isn’t enough to start the car but keep the computer alive.

Hope this makes sense,

Henry

[kcwitt]

Had the same code being thrown. Ended up finding the 250amp main fuse wasn't tight enough. Tightened it & no problem since. I did also get a Lund tune for another code that was being thrown. 6000+ miles now with no problems.

[BEAR-AvHistory]

What they said plus a bit. I had the same issue and tracked it to shutting off my battery main cutoff switch (no keep alive yet) too soon not allowing the computer the 5 or so seconds to shut down properly. My fix was to wait 10 seconds after shutting off ignition before shutting of main battery switch. I then installed a 10 amp automatic circuit breaker across the cut off switch so there was always 10 amps of power which isn’t enough to start the car but keep the computer alive.

Hope this makes sense,

Henry

Agree its a smart thing to do.

[GTME96]

Thanks for the responses. I have an appointment to get it tuned. Hope that does the trick.

I don’t have a battery cutoff switch. It is still not clear if the error code is related to the stall. Maybe it isn’t. I’ll check the main fuse. If the error code is not related to the stalling issue, how important is that to track down? If the tune gets the car performing like it should, is the error code a big deal?

[edwardb]

Thanks for the responses. I have an appointment to get it tuned. Hope that does the trick.

I don’t have a battery cutoff switch. It is still not clear if the error code is related to the stall. Maybe it isn’t. I’ll check the main fuse. If the error code is not related to the stalling issue, how important is that to track down? If the tune gets the car performing like it should, is the error code a big deal?

Once you have all the known issues addressed, clear the code. It will come back if still an issue. Once everything is done and tuned, you should be able to run with zero codes.

[GTME96]

Once you have all the known issues addressed, clear the code. It will come back if still an issue. Once everything is done and tuned, you should be able to run with zero codes.

Update on my Coyote Gen 3. I had it towed to a tune shop. They couldn’t get it to run long enough to put a tune on it. Ford Performance asked for the PCM to be returned to them so they could reflash it with their base tune. I dod that, reinstalled it last night, and the same thing happened. Idles fine. Stalls going forward. Drives fine in reverse.

I did a download of data at idle and uploaded it to Chat GPT with a description of the problem. Chat GPT indicated the most likely problem is a faulty Vehicle Speed Sensor. I dont know what would have changed since the many test drives that i did. But that explain why it runs in reverse but not forward?

I sent this info to Ford Performance, but they haven’t come back with anything yet.

[edwardb]

The Ford Performance control pack doesn’t monitor vehicle speed. No input for it. Not used in the calibration. That’s not it.

[GTME96]

The Ford Performance control pack doesn’t monitor vehicle speed. No input for it. Not used in the calibration. That’s not it.

Confirmed that is not it. I removed the speed sensor plug from the sensor and went for a test drive. No changes. Stalls going forward. But still idles ok amd i was able to drive it home in reverse.

Any idea why it drives in reverse, but stalls going forward?

[Blitzboy54]

The engine runs the same in either direction. The transmission determines forward or reverse. I suspect it has more to do with RPM’s. Your barely over idle in reverse. When you say you unplugged the engine speed sensor what exactly do you mean? The only speed sensor I’m aware of on the engine is the crank position sensor.

Is it a long stick looking thing that sits on the back near the bell housing? At the back of the engine in this picture it has the copper tip pointed at the crank in the upper left

https://thefactoryfiveforum.com/attachment.php?attachmentid=208533&d=1736019397

It reads the pulse ring on the crank

https://thefactoryfiveforum.com/attachment.php?attachmentid=211088&d=1741038034

If this is the case then I agree with Chat GPT. If the sensor is marginal it's loosing the RPM signal at higher speed. This would cause the engine to shut down. If the Coyote can't see the RPM it shuts off. Feel free to ask me how I know.

The good news is (again if this is right) the sensor is both not that expensive and easy to replace. Also check the wiring harness plug for a pushed pin. The bad news is if the problem is the pulse ring you have to remove the drive shaft, separate the transmission, remove the clutch and replace the ring.

My next question is who did you get the engine from. Ford makes a high RPM pulse ring that requires a special adjustment to your tune. It is also possible you have that ring and your tune doesn't see it. In the picture you can see the wider gap in the ring. That is what the control pack is looking for. The high RPM version has a taller wall.

[GTME96]

The engine runs the same in either direction. The transmission determines forward or reverse. I suspect it has more to do with RPM’s. Your barely over idle in reverse. When you say you unplugged the engine speed sensor what exactly do you mean? The only speed sensor I’m aware of on the engine is the crank position sensor.

Is it a long stick looking thing that sits on the back near the bell housing? At the back of the engine in this picture it has the copper tip pointed at the crank in the upper left

https://thefactoryfiveforum.com/attachment.php?attachmentid=208533&d=1736019397

It reads the pulse ring on the crank

https://thefactoryfiveforum.com/attachment.php?attachmentid=211088&d=1741038034

If this is the case then I agree with Chat GPT. If the sensor is marginal it's loosing the RPM signal at higher speed. This would cause the engine to shut down. If the Coyote can't see the RPM it shuts off. Feel free to ask me how I know.

The good news is (again if this is right) the sensor is both not that expensive and easy to replace. Also check the wiring harness plug for a pushed pin. The bad news is if the problem is the pulse ring you have to remove the drive shaft, separate the transmission, remove the clutch and replace the ring.

My next question is who did you get the engine from. Ford makes a high RPM pulse ring that requires a special adjustment to your tune. It is also possible you have that ring and your tune doesn't see it. In the picture you can see the wider gap in the ring. That is what the control pack is looking for. The high RPM version has a taller wall.

I bought the engine from Forte Parts Connection. Mike said he has not seen this condition before.

The sensor plug that I removed was the speed sensor pkug on the TKX transmission. If the signal wire was removed, why would it run in reverse but not forward?

Also, it is stalling at very low speeds going forward. Im being extremely gentle with it and driving it on flat ground. I cant get imore than ~100 ft before it stalls. Once it stalls, it will restart, but stalls almost immediately when i try to go forward again. Then i drive it home in reverse with no stalls.

Thanks again for the response.

[Blitzboy54]

I see. My thinking was that in reverse you would be creeping vs driving forward. Sounds like your driving conditions are the same in both directions so that is a real mystery. Like Paul said the control pack doesn't have an input for speed. Your sensor in the transmission is tied directly to your gauge.

It's disappointing the best Ford can come back with is a re flashed PCM. I had mixed success with them as well.

I wonder if your PCM relay is chattering/failing. I believe the PCM relay R1 is the same as the cooling fan relay R2 (see attached). You could swap them and go for a short drive up and down the street. It would tell you if your situation has changed immediately long before you need your cooling fan to work. Might explain why it worked and seems to be getting worse.

Next thing is your battery/alternator. Are you getting 14v at idle? Is your battery at 12.5 ish at start?

220480

[GTME96]

I have replaced the R1 relay and that didn't change anything. Battery has been tested at Autozone and said it was OK. Battery voltage at idle a little north of 12V. I honestly haven't paid that much attention to the battery gauge. I notice it is over 12V, so I thought it was OK.

[Blitzboy54]

Your battery at idle should be 14v. Sounds like your alternator needs to be tested next.

[danmas]

Is it possible that you have a loose wire that is put under strain when driving forward but not when reversing? I would expect you to see the issue regardless of direction traveled if it was a failing component. This leads me to believe it is related to the stress on a component due to direction traveled but I admit this is a wild *** guess.

Dave had a problem with random stalls in his roadster and it was related to an electrical short in his fuel pump wiring: https://thefactoryfiveforum.com/showthread.php?51662-Papa-s-Random-Stall-Issue-Data-Log-Captured!&p=585690&viewfull=1#post585690

[GTME96]

Is it possible that you have a loose wire that is put under strain when driving forward but not when reversing? I would expect you to see the issue regardless of direction traveled if it was a failing component. This leads me to believe it is related to the stress on a component due to direction traveled but I admit this is a wild *** guess.

Dave had a problem with random stalls in his roadster and it was related to an electrical short in his fuel pump wiring: https://thefactoryfiveforum.com/showthread.php?51662-Papa-s-Random-Stall-Issue-Data-Log-Captured!&p=585690&viewfull=1#post585690

Maybe. Checking fuel pressure is on the to-do list. It holds 65 psi at idle, so I initially rules out fuel delivery as an issue.

I did a couple of experiments last night. Put the rear axle up on jack stands. Put the car in first and let out the clutch with no throttle pressure. The wheels spin with no stall. I applied some throttle pressure to about 2000 rpm. The speedo registered about 20 mph. After a few seconds, it started to stall, but recovered. That kept happening over and over again. Something appears to be limiting fuel, but I don’t know why. Trying to figure out if this is mechanical or electrical. Still can’t explain why it runs in reverse, but not forward.

I then changed the position of the MAF to see what that would do. It is about 1 o”clock on the intake tube. Moved it to 3 o’clock. Did the same test. It stalled immediately when I pulled off the clutch. Moved the MAF to about 10 o’clock, and performed about the same as it was at 1 o’clock. Obviously, MAF position has an impact on performance, but that didn’t fix anything.

Btw - Ford Performance has escalated this to engineering because I have “a unique set of circumstances.” Haven’t heard back from them yet.

[danmas]

I’m going to bet this is power related. Reading up on the error code it happens when the pcm isn’t able to write successfully to nvram (non volatile random access memory) and typically it’s associated when the engine is shutting down. So, while driving forward something may be telling the computer to shutdown or you may have power problems. This could be a fuse, a relay that is failing or isn’t tight in the box or a grounding issue. When driving forward something may be pulling more power from your system or perhaps a grounding issue. Under load it happens immediately. Reduce the load (jack stands) and the computer has a chance to recover as I bet the power drop isn’t as dramatic. Read up on Dave’s experience and it sounds similar but not the same as yours. I’m guessing…

I think Jesse was on the right track. There are a bunch of discussions around how to trouble shoot this. Consider this video: https://www.youtube.com/watch?v=qezAJ9bXd1k

I am assuming you still have the code up. Also, if you have a logger you can see the fuel pressure in the logs if it’s configured correctly….

I’m going to guess your pcm is fine as ford returned it to you. That means it is likely something feeding or interfering with the pcm.

[GTME96]

This might be power related. I had the battery tested and Autozone said it was fine and had 80% charge on it. But I have noticed that it does not hold a charge like it should. If it sits for a week, it needs a charge before it can crank the car. That said, it seems to recharge once the engine is running.

I've checked all of the grounds. They are still secure. If it is a grounding issue, it is that something that shouldn't be grounded is grounding. But I haven't been able to find that either. And the only wiring I did since last known good condition were the lights and turn signals. And it stalls when those aren't on.

I will check fuel pressure while in first gear when I can get another set of eyes to watch it while I drive forward on jack stands. But I really doubt that is it. Why would the fuel pressure be any different in reverse?

As far as the error code, is whatever condition that is causing the code also causing the stall? Or is the fact that it is stalling causing this error code? I'm leaning towards the latter. The stall is not a normal shut down cycle for the engine. I suspect if the engine doesn't stall, it will stop throwing this code. But open to suggestions. Since I don't know what the problem is, I have to be open to all options.

Also, this was a complete kit build - all new parts. I didn't use any donor parts. So I'm not dealing with any corrosion or aged parts.

And thanks as always for the feedback. It us much appreciated.

[danmas]

My guess is that it is power related and that causes the computer to lose power/short out and that triggers the error code. Test the alternator. Is the alternator grounded? The video I linked shows how.

Check each fuse and relay and make sure they are tight/good. Regarding fuel pressure, if the short is in the fuel system and it is intermittent due to a bad connection you would see a drop in fuel pressure before the stall, but you would need something like forscan to see it as it would be quick. I don’t know why it doesn’t happen in reverse. Maybe the connection is not put under stress in reverse and no short. Maybe in reverse a power path isn’t actuated that has the short?

Perhaps try disconnecting your turn signals and lights ( it isn’t unreasonable that a wiring harness was put together wrong). Is it possible your ignition is shorting out or the power wire for the computer is not clean? I don’t have a coyote or a ford computer. If I did have this problem i would start at the alternator and then disconnect everything not needed for first start, one thing at a time.

Good luck! I hope this helps…

[GTME96]

I want to thank everyone that replied to try to diagnose this problem. You were all polite enough not to assume pilot error. But that is what happened. As I'm sure many of you know, the battery cable is much longer than it needs to be. When did the rough in, I pulled the excess length into the trunk and had it spooled, zip tied, and secure. Apparently, when I took the battery out to install the carpet, I unspooled the cable and some of the excess slack slipped under the trunk. It was enough that the battery cable was resting on the drive shaft. It was only a matter of time before it wore through the loom and insulation and caused a short. I suspect it drove in reverse because the drive shaft spinning the other direction likely moved the cable so the exposed wire didn't hit grounded metal. But that would have eventually failed as well.

Not my proudest moment. But after patching that up and making sure the cable was secure away from the drive shaft, she's running like she used to. I took her out to a restaurant last night and to work this morning. No issues with the engine.

So, that should wrap up this thread. Thanks again for the free advice. It is much appreciated.

[Blitzboy54]

That is actually amazing. Super glad you figured it out. It is a real guy punch when the part of the car that is that expensive doesn't work right.

Thank you also for following up. Personally I have never learned anything by doing it right the first time.

Congrats on figuring it out.

[danmas]

I’m so happy for you. It sucks to have something you built go sideways. But it’s great when you figure it out. That’s awesome! Well done and thanks for following up.

Best,

Dan

[nashuanuke]

just got the same code, happened while driving, went over a small bump, engine died and now it turns but won't start. I was certain there's a wire connector that shook loose somewhere but all the obvious stuff looks good. I'm going to start walking down each line and reattaching everything today.