Limp Mode / P061C. Looking for advice / help

[F.D. Sako]

Check out this thread for reference

https://trackmustangsonline.com/index.php?topic=7537.50

 

[2012-Boss]

He said he wrote down the codes that got thrown. He mentioned not seeing anything unusual besides the throttle body issue, but I'm not sure that he really looked at live data. I should have asked him about that...

Out of curiosity, did your car throw a CEL, wrench light, or both?

The car threw a CEL on track for the p061C code and went into limp mode. It also threw numerous misfire codes and went into limp mode. The car ran fine on the street.

The tech monitored live data with the IDS. Based on that, he knew something was wrong, but not what.

 

[Berol]

New battery in the car to replace the 5 year old OEM one on it's last legs.

Unused takeoff throttle body from a new crate motor is on the car. That should solve the limp mode issue I saw on the street.

I won't go so far as to say the car is fixed but I'm confident enough to say I'm going to Sebring March 26th. If I fall into limp mode, I still have an unresolved limp mode issue at the track. The only way to solve this will be to invest in Ford IDS myself and drag it to the track so I can diagnose it in situ. I hope it doesn't come to that (and don't think that it will).

 

[Berol]

Guess what? IT WORKS! Ran 5 solid sessions at Sebring. Turned several laps more than 6 seconds better than my previous best lap there. It's Easter, so for any doubting Thomas out there, here's some proof:

https://www.youtube.com/watch?v=ASDkukBxIQM

This problem was a bear to solve. If I had Ford software/IDS at the track, it would have been pretty painless.
Lessons learned (for anybody who does a search in the future):

• P061C was present, my SCT could see it. Likely cause was the abrasion in the wiring harness on the driver's side exhaust cam position sensor. This ALWAYS yielded a CEL, with a wrench light and limp mode.
• The throttle body was bad. Only the dealer could pull this code, the SCT wouldn't. It was P012X (sorry, I didn't get the last digit, I didn't want to hawk over the tech's shoulder while he was working. There's several codes in that series, all dealing with throttle position). This would always give me a wrench light and limp mode, but no CEL
• The combination of those two issues, with nearly identical symptoms, made this difficult to solve.
• Making this even more difficult to solve, when data logging on the street with my SCT x4, I would consistently see instances of spurious engine RPM signal. Sometimes it was 0, sometimes it was 5, sometimes it was 1.42E-50. All kinds of stuff that made no sense for about 5 data points, then it would be fine again. Since I already knew I had engine RPM performance issues with P061C, I kept assuming that this behavior was indicative of poor RPM monitoring performance and likely would cause full limp mode on the track. I was wrong.
• For some reason, the behavior listed in the bullet point above, IS TOTALLY NORMAL. Don't ask me why. It's possible that the SCT doesn't have enough bandwidth/resolution to manage a full suite of data points and when it doesn't know what to do, just throws out random crap. That's the best guess I have.
• The SCT x4 is fully capable of doing a CKP misfire relearn. It's exactly the same thing as Ford IDS. Don't let anybody tell you anything differently. To be honest, this alone is worth buying an x4 and carrying with you to the track even on stock tuning. Code reading and/or aftermarket tuning are icing on cake.
• The FRPP Cobra Jet High RPM pulse rings will have beat up teeth. They add in new material in the skipped tooth area, grind out material and smooth it all out. They seem to be more worried about smoothing out the troughs than the teeth. I bought another new FRPP Pulse Ring, and it has beat up teeth just as bad as my first one did. The trough areas are important between the teeth. The teeth don't matter nearly as much.
• Nobody has any clue why Ford sells VCT solenoids that having wiring posts oriented backwards from one another. I think this is really dumb, and caused me no small amount of frustration with them.
• Random stuff happens. Sometimes, two things can break at once. Don't rule that out. Who would have thought a throttle body would go bad at the same time I swapped a clutch?
• Probably tons more but I forget. It's been 10 months to the day since I lost the clutch.
• Last but not least, THIS FORUM IS AWESOME. I could list people by name, but many thanks to everybody who helped pitch in with ideas and solutions. If you're ever in Florida, I owe you a beer.

 

[ArizonaBOSS]

Glad to hear this is finally all over for you, and you can get back to really enjoying the BOSS!

 

[302 Hi Pro]

Berol:

Great news! You have to be a happy man now that this ordeal is finally over! Most would not have gone through it and would have sold their Boss 302.

Great documentation, photos and summary.

Thank you for posting this.
302 Hi Pro

 

[AUStheWOLF]

Guys, forgive me for bringing this thread back from the dead. I have P061C DTC code also (in addition to a P0320), and I thought I would ask here for pointers. This forum is incredible, sounds like you guys really got Berol straight on his issue.

I have an extremely low-mileage (3,000 miles) 2012 Boss 302, that I have not been able to use much due to my work situation for the past few years. I ran into a problem a few months ago and I have tried a few things to correct the issue, but the problem is difficult to diagnose. Hopefully this is an easy fix, but I thought I would start by explaining the symptoms and what I’ve done thus far to trace down the problem.

After letting the battery go completely dead, I have brought it back to life more times than I would like to admit… realistically, over four times in the course of the vehicle. After moderate use, about twenty minutes to an hour, the car experiences a faint blip that feels like fuel cut. This blip/fuel cut increases to full breaking up at moderate speed, and will shortly mean you will not be able to move your car at ANY speed. Fortunately, the last time this happened, I was close to my home and returned to the garage.

To diagnose if I had a potentially dead cell or faulty alternator, I decided to replace the 6-year-old battery. After taking a test drive, I was confident this solved the issue. However, after twenty minutes of use, and sitting idle in front of a friend’s house for around three minutes, the car experienced a complete fuel cut and DTCs (both wrench and CEL). I have not had this problem when the car is “cold,” and if I clear the DTCs, the car drives normally. My best friend is a mechanic, and we diagnosed what we could in the neighborhood where I “broke down.” I had to clear the DTCs three times in a seven mile drive.

The following Diagnostic Trouble Codes (DTCs) were pulled from a Snap-On Verdict D7:
P0320 | Ignition/Distributor Engine Speed Input Circuit
P061C | Internal Control Module Engine (RPM) Performace

· Battery maintained around 13.5-13.7V on the multimeter. At crank, it was around 13.5V (replacement, new OEM Motorcraft battery), and climbing when I put on the air conditioner. Good news for battery and alternator!

· Audible prime from fuel pump when key in accessory, we hooked up fuel pressure gauge directly to a T-fitting to check fuel pressure at idle (with and without giving throttle). At this point we cleared the CEL to diagnose. The car was getting steady ~50-55psi at idle, no variation while raising RPM. I also replaced the Fuel Relay box fuse with a spare (just to eliminate this variable), the relay was not hot to touch.

· We inspected the engine harness, battery cables, and unclipped the back seat to check wiring to fuel pump/hat assembly – no obvious signs of fraying.



From what I have read recently, the fuel filter is a “lifetime” part that does not require replacement. I cannot eliminate the fuel pump as a culprit entirely – but, as I mentioned above clearing the code does make the problem disappear for a short interval. The only way I think this can be a fuel pump is if the signals sent from the fuel pump to PCM were erratic/inconsistent. However, I have strong fuel pressure at idle and the car runs great until the DTCs return.

I have seen some circumstances that were similar, although they do not exactly line-up… Here will be my repair path of replacement parts to fix the problem.

· I am aware that the Crankshaft Position Sensor (CKP) has a TSB for a missing O-ring. In some instances online, I was able to read that users with missing/defective O-rings have experienced similar symptoms, although somewhat different DTCs. If I find a damaged O-ring, I will replace the O-ring and keep the original sensor. Hopefully this will avoid needing a “crank relearn.” (This will be Step 1)

· The fuel pump can be replaced easily, and would be worth my time to eliminate as a culprit. I will especially inspect the wiring to the fuel pump and fuel hat assembly if I go this route. It will also be wise to replace the “lifetime” fuel filter at this time. (This will be Step 2)

· The Camshaft Sensors produce a similar symptoms, but create different DTCs – so hopefully I can eliminate replacing them for the time being. If all four need to be replaced, it is not terribly expensive ~$100, or difficult. (This will be Step 3)

· Unfortunately, I believe this only leaves two culprits – a faulty PCM or engine harnesses. Neither would be easy to do, or cheap! This would be a last resort.



Please spare my feelings – tell me what you guys are thinking about my analysis above… Am I forgetting to check anything obvious? What is your gut impression of the symptoms? Have you had any similar experiences or any pointers to troubleshoot the problem? Thank you all for your time, this seems to be one of the only Mustang forums that really answers questions and takes the extra steps to help the forum members. Thanks in advance to 302 Hi Pro and anyone who would like to chime in to help out. Sorry if this post is long, I just want to make sure to give you all the info.


Thank you sincerely for your time,
Austin

 

[TMSBOSS]

Austin

Good analysis. My negative experience was limited to the crank sensor and the o-ring fix. I replaced the sensor, warranty. Installed the o-ring and had to do the relearn twice, both times with laptops with the Ford tool. Not sure this is your problem. Although the o-ring is without a doubt the cheapest route. You may want to go there also. One connector, one bolt and the sensor pulls up and out.

 

[JAJ]

... tell me what you guys are thinking about my analysis above… Am I forgetting to check anything obvious? ...

I'm not a Boss expert, but I did a ton of tuning with SCT Pro Racer on my 2011 Mustang GT 5.0, which uses the same ECU. I reflashed the ECU over 100 times while I figured out a smooth running tune with a TVS2300. I occasionally had a similar problem to yours and it came up about 20 minutes after a reflash. Except my engine would either stumble if it was moving along in gear, or it would die if the clutch wasn't engaged. I eventually figured out that the Keep Alive Memory (KAM) was corrupt. KAM is where the "learn" data lives and there's a switch that connects the KAM to the working memory set in the ECU once the engine is warm, which takes about 20 minutes. If the KAM is corrupt, the engine will struggle to run.

You said your battery has gone flat a few times - that could lead to a corrupt KAM. It shouldn't, but it could. I believe your SCT has a "Clear KAM" function - give it a try. It might help.

 

[AUStheWOLF]

Berol, I'm hoping I don't have half the problems you went through in this thread.

Austin

Good analysis. My negative experience was limited to the crank sensor and the o-ring fix. I replaced the sensor, warranty. Installed the o-ring and had to do the relearn twice, both times with laptops with the Ford tool. Not sure this is your problem. Although the o-ring is without a doubt the cheapest route. You may want to go there also. One connector, one bolt and the sensor pulls up and out.

If this is my only thing to fix, I will feel truly blessed... Thank you for the advice!

 

[AUStheWOLF]

I'm not a Boss expert, but I did a ton of tuning with SCT Pro Racer on my 2011 Mustang GT 5.0, which uses the same ECU. I reflashed the ECU over 100 times while I figured out a smooth running tune with a TVS2300. I occasionally had a similar problem to yours and it came up about 20 minutes after a reflash. Except my engine would either stumble if it was moving along in gear, or it would die if the clutch wasn't engaged. I eventually figured out that the Keep Alive Memory (KAM) was corrupt. KAM is where the "learn" data lives and there's a switch that connects the KAM to the working memory set in the ECU once the engine is warm, which takes about 20 minutes. If the KAM is corrupt, the engine will struggle to run.

You said your battery has gone flat a few times - that could lead to a corrupt KAM. It shouldn't, but it could. I believe your SCT has a "Clear KAM" function - give it a try. It might help.

I can tell you when I cleared the KAM on the drive home, drove like a champ - until I lifted throttle. The car gave up the minute I got out of the gas, would completely fall on its face and force you to get off the road. Felt like someone was throwing you in neutral, but your revs would not stay high enough to keep moving.

When I cleared the KAM, I accelerated as fast as I could to get down the road while the car was running. This minimized the time between breaking down. It ran perfect until I lifted throttle, real bad problem.

 

[JAJ]

...When I cleared the KAM, I accelerated as fast as I could to get down the road while the car was running. This minimized the time between breaking down. It ran perfect until I lifted throttle, real bad problem.

Sorry to hear it - it was worth a try. Did you turning it off and restarting after the fail the followed the KAM reset? I'm grasping at straws here, but it's the only other thing I can think of. Good luck!

 

[AUStheWOLF]

Sorry to hear it - it was worth a try. Did you turning it off and restarting after the fail the followed the KAM reset? I'm grasping at straws here, but it's the only other thing I can think of. Good luck!

Not entirely, we tried clearing the KAM and I barely made it to my driveway. By this point the car was idling real funky and killing itself in my driveway. I felt fortunate to get home, and couldn't even pull in the garage. I left the car alone for half a day, cranked up and idled normally and I was able to move it in the garage.

I have the battery disconnected for a few days now, until I can get to Ford parts to pickup a new crankshaft position sensor. Do you recommend installing the new sensor, clearing KAM, doing crankshaft relearn (I borrowed an SCT X4 from a friend)?

 

[AUStheWOLF]

Thought I would ask this, as I have not tried yet......

I am borrowing a BAMA-branded SCT X4 from a friend. He has a 2015 GT, tuned with headers exhaust intake etc... If his tune is locked on the scanner, will I still be able to use the Special Functions menu to do a crank relearn and clear keep alive memory (KAM)?

To clarify, I am not trying to tune my car! I only need to use the SCT X4 to run these two features - KAM clear and crank relearn. Is there any chance this will calibrate the KAM and relearn crank for his mods/parameters if it allows me to perform the functions?

 

[JAJ]

Thought I would ask this, as I have not tried yet......

I am borrowing a BAMA-branded SCT X4 from a friend. He has a 2015 GT, tuned with headers exhaust intake etc... If his tune is locked on the scanner, will I still be able to use the Special Functions menu to do a crank relearn and clear keep alive memory (KAM)?

To clarify, I am not trying to tune my car! I only need to use the SCT X4 to run these two features - KAM clear and crank relearn. Is there any chance this will calibrate the KAM and relearn crank for his mods/parameters if it allows me to perform the functions?

That's a question that you should ask SCT. AFAIK, the special functions should work on any car, but if the X4 is somehow locked to his 2015, which has a different ECU, the results could be unpredictable. When I was doing my tuning on my car, I also had a Ford Racing Procal tool (looks similar to an X3 except its covered in rubber and it's blue) and I used it for KAM clear and crank relearn. My SCT X3 never inspired a lot of confidence for anything other than straight up calibration loading and unloading.

As for your question about replacing the sensor, in theory, disconnecting the battery resets the KAM. That's the shade-tree mechanic's reset tool. So, just do the crank relearn after the sensor install and see what happens from there.

BTW, you haven't mentioned DTC's again - are you still getting the same DTC's? Or are you getting poor running and no DTC's?

 

[AUStheWOLF]

That's a question that you should ask SCT. AFAIK, the special functions should work on any car, but if the X4 is somehow locked to his 2015, which has a different ECU, the results could be unpredictable. When I was doing my tuning on my car, I also had a Ford Racing Procal tool (looks similar to an X3 except its covered in rubber and it's blue) and I used it for KAM clear and crank relearn. My SCT X3 never inspired a lot of confidence for anything other than straight up calibration loading and unloading.

As for your question about replacing the sensor, in theory, disconnecting the battery resets the KAM. That's the shade-tree mechanic's reset tool. So, just do the crank relearn after the sensor install and see what happens from there.

BTW, you haven't mentioned DTC's again - are you still getting the same DTC's? Or are you getting poor running and no DTC's?

I am getting the same DTCs as earlier, so the battery I replaced did not fix the problem. At least I can confirm this was not a low voltage situation cutting power to fuel pump. I also confirmed fuel system is running well (~50-55psi pressure) hooking up the T-line and gauge before the fuel rail...

I haven't had a chance to do anything to the car since making the above posts... Need to source a crank position sensor (CKP) from the dealership, start by inspecting O-ring for damage (if there was ever one present on the senor), replace O-ring and hopefully avoid relearn... If I still have the same problem - replace the sensor, do a relearn at the dealership. I was hoping the SCT X4 could do the crank relearn, but I really may be setting myself up for PCM/ECU damage by flashing with a tuner that has been coded for different mods and different generation. Too many uncertainties, instead of just paying for a short amount of labor.