2013 GT500 confusing everyone

This is my first post but in regards to the reason why I joined the forum to begin with . I have a 2013 GT500 I have had the car since it was almost new it only had 1400miles and was less than 6 months old . The car now has 30k miles but it has been an electrical nightmare most of the time I have had it . It failed its first inspection because of failed emissions test when the car only had 2500 miles on it . Ford service couldn’t figure it out and blamed the O2 sensors they replaced them and finally got the car to pass emissions . Then it did the same thing the next year it failed emissions a couple of years it did pass but I honestly have lost track of how many times it failed inspection for emissions at this point. Now I’m dealing with the same issues but last year it got worse because it started going into limp mode. When it went into limp I took it to a local shop who told me they were confused because it ran great till it didn’t which is right , it was going into limp randomly and it made no sense . They then made up an excuse to charge me 1300 for something the car didn’t need . After that I took it to a reputable shop but they were too booked for a while to fix so I started working on it myself . Ok the car is back to stock but the only thing I had done was install a steeda CAI . what I have discovered is honestly shocking I found a Burnt plug that was right in front of everyone and it had been shoved under the CAI out of sight . It was a plug that has 6 wires that I think go to the MAF and intake air temp it had been arcing and I know it had not been checked because it fell apart when i disconnected it . The plug was attached to the 14290 harness so the only options were to splice in a new connector or replace the harness I attempted to splice one in but must have messed it up so I went ahead and replaced the 14290 harness which is big but was essentially just installing and plugging in . When I first installed it it worked but was I having headlight issues which I determined was a ground issue and was able to fix . I was hoping it would be fixed and I would finally be done with all the electrical issues but that’s not what happened. When I drive car it was driving great but was showing a p0300 code which is an issue it had before the reputable shop had already checked and verified the car was ok but they couldn’t say where the misfire were committed from but it wasn’t in the cylinders. So at this point I’m getting the p0300 and the think car scanner I have is telling me the P0300 is the only code but the FDIM front display interface module,GPSM Global Positioning System module and IPC instrument panel control module are Not responding . The confusing part is the front display does not seem to be acting weird and when I checked the global positioning it knew where I was . They seem to be working but the think car says they are not responding what could this be ? The picture attached is circling the plug that had been burnt before I replaced it and it had been shoved under the CAI.

So at this point I’m getting the p0300 and the think car scanner I have is telling me the P0300 is the only code

Is the MIL on and the P0300 still stored? If so, don't clear it. Use your ThinkCar scanner in Global OBD mode to check for the Freeze Frame associated with that code, and Mode $06 for misfire counts.

Those two things will tell you when the misfire is happening, which cylinders are misfiring, AND who the worst offenders are (if any). Remember, if you clear the codes, all that info disappears.

FDIM front display interface module,GPSM Global Positioning System module and IPC instrument panel control module are Not responding

So they're working correctly, but the ThinkCar just won't get codes from them, correct? As long as you have the vehicle ID'd correctly, I would probably put that down to an issue with the scan tool. Come back around to that when you've got the P0300 fixed.

Does the VIN in the PCM match the VIN sticker in the drivers door jamb? Was the PCM tuned at any point?

I had cleared the codes yesterday but drove the car this morning I may be wrong and please tell me if I am . I am and have been getting the u0401:81-0a code but the battery is fully charged . It is telling me it is the IPC but it IPC seems to be working correctly . I was told that if the car has a code it will stop it from completing other tests . Some of the tests not completed were the o2 that are showing not ready which could be the reason for the P0300 ? I have checked to make sure the think car is getting the right information by verifying the vin it finds . I also have the obdMx + scanner and it says essentially the same thing the think car is saying. I know the O2 are not bad I changed them the MAF sensor too. What could the problem be ? The car did have a previous tune but I made sure to save the original tune on the x4 that I have so when the car started having issues it was put back to original to figure everything out easier .

Bethany5436 wrote:

I am and have been getting the u0401:81-0a code but the battery is fully charged . It is telling me it is the IPC but it IPC seems to be working correctly .

Thanks for the code reports! I took a screenshot for reference:



The U0401:81-0A refers to invalid data received from the PCM. The invalid data is, in this case, that the engine is misfiring. :silly: Almost certainly a symptom of the P0300 and P0316. Disregard the U0401 until you get the misfire fixed.

I was told that if the car has a code it will stop it from completing other tests . Some of the tests not completed were the o2 that are showing not ready which could be the reason for the P0300 ?

The O2 monitors being incomplete is more likely to be caused by the misfires (and clearing the codes), not the other way around. Again, fix the miss and recheck.

What could the problem be ?

You still need to identify which cylinders are misfiring (and when) before we can discuss what the cause might be. Put the ThinkCar to work and gather more information. Misfire counts AND Freeze Frame data.

Thanks maybe a little more history for the car might help. This P0300 and u401:81 issue I have been fighting for a while I had taken it to shop very close to me when it first went into limp and the guy ripped me off and charged me $1,300 for something the car didn’t need so I asked a guy that also lives in Fort Worth with a car like mine who he suggested and he said HPP racing others also suggested them too. They are about 45 mins from me So I took it there and they are great at what they do I had thought they may not be real because reality tv lol but they are and they are truly honest and good at what they do I honestly had never seen so many gt500 in one spot . I went at the end of the year they tried a tune incase the current one had been corrupted . But that wasn’t it I took it back and they checked to try to pinpoint where the misfire were coming from but they couldn’t at that point but I asked them to verify it wasn’t misfire in the cylinder because I was worried that it could cause damage and they said it wasn’t misfiring in the cylinders they made it a point to check that . They said they checked everything and at that point couldn’t verify the exact spot causing it . They said I would have to come back after the first of the year because they were too busy then and I understood . So after finding out my car was not burning up it’s cylinders and having confirmation the shop before them had ripped me off I decided to do it myself because I wasn’t very patient . Ok so I did find the burnt plug and after I fixed that the p0300 codes went away until the u401:81 code came back which from what I understand can cause misfire type symptoms . I then found the scanner Danner site and thought maybe I could find tips to better use my tools to pinpoint the spot instead of having to pull everything apart. I have taken it to ford service more than once and the issues I had with them are laughable they once even put my exhaust back in wrong .