2019 Big Horn 1500 - Error Code P1DF3 ECU Not Initialized

[PKCooper]

Any updates on this? I'm completely unfamiliar with vehicles in general and I've been trying to research this problem to no avail!

I have a 2019 Dodge Ram 1500 Big Horn 5.7 Hemi that's rear-wheel drive (sorry, don't know how specific I need to be!) that I bought back in February.

Around April 15th, I noticed that the check engine light was on. I kept driving it for a few days because I didn't have time to take it into the shop. Well, about a week later I tried to start it and the battery was dead. I jumped it, and the check engine light was still on but it ran for about 3 days. Then I tried to start it again and the battery was dead again. I had it jumped again and this time, I drove around for about an hour to charge the battery. The next time I started it, it started up fine and there was no check engine light.

I drove it for another 2 weeks and again I noticed the check engine light. This time, I took it to Autozone and asked them to check the codes. There were two of them, both were P1DFE - ECU Not Initialized. They also checked my battery and my alternator and said that both of them were good.

I took it to a local dealership and they said my battery was bad, though I think they just wanted to make a quick buck. I was hesitant, but went ahead and did it just in case they were right.

Yesterday, I started up my truck and the check engine light is on and I'm pretty sure it's the same thing because at first my uConnect radio wasn't showing a display other than the logo.

I just want to fix this once and for all.. what could be causing my battery to drain? I unplugged my USB charger and turned off the A/C as well as the screen/radio before parking my car. I don't know if that'll stop it from draining, but I really want to pinpoint the problem so I can just cough up the cash for a fix.

Thank you!

I showed these service bulletins (they seemed relevant) when I took it in to replace my battery and they said it doesn't apply to my vehicle's VIN??

https://static.nhtsa.gov/odi/tsbs/2020/MC-10173360-9999.pdf
https://static.nhtsa.gov/odi/tsbs/2020/MC-10173368-9999.pdf

I would figure all make/models would have the same service bulletins..

 

[SixAddict]

I guesss you have had no answers or resolution to this condition.?

I went to start my 2019 Ram Laramie 1500 2WD and nothing but click. Got a jump drove it home with check engine light on solid. Got home replaced battery, check engine light on still.

Went to Oriellys to read code and it’s P1DF3 ECU Not Initialized. They cleared code and as soon as I started it check engine light came right on solid.

I realize here in AZ we need new batteries every two years and I tried to get three years out of mine. I’m stumped as to this code because it calls out shift module or trans module?

Guess I’ll have to take it to the stealership tomorrow.

After reading your posted bulletin looks like that’s my truck. Looks like it needs software update for TCM. Ggreeeaaatttt.
Not even 30 k on the clock yet….

 

[Vdawg]

Code P1DF3
Has this been resolved? I'm having the same issue as of today with my 2019 Reble. Came out from work and the truck did not start so I had to brake out my GB40 Noco Booster to jump it. As I got in and started, i noticed it was a little sluggish, and the engine light came on. I took a to autozone and they pulled up a P1DF3 code. This is my first and only issue i've had with the truck... wtf!!!!!

 

[rkowalski1963]

I guesss you have had no answers or resolution to this condition.?

I went to start my 2019 Ram Laramie 1500 2WD and nothing but click. Got a jump drove it home with check engine light on solid. Got home replaced battery, check engine light on still.

Went to Oriellys to read code and it’s P1DF3 ECU Not Initialized. They cleared code and as soon as I started it check engine light came right on solid.

I realize here in AZ we need new batteries every two years and I tried to get three years out of mine. I’m stumped as to this code because it calls out shift module or trans module?

Guess I’ll have to take it to the stealership tomorrow.

After reading your posted bulletin looks like that’s my truck. Looks like it needs software update for TCM. Ggreeeaaatttt.
Not even 30 k on the clock yet….

Did the Dealer correct? What did they do? I just had the same issue pop up this weekend with the same error code. Curious to how they fixed it and cost? Thx

 

[SixAddict]

Actually the code cleared itself. Dealer said so many start cycles will clear that code. I guess next time I change the battery I throw my charger on it.

 

[jmvienneau]

FIX IT
I had the engine code P1DF3 on my 2019. Battery was dead only had 10.8Volts. So I disconnected the battery cable and charge the battery over night. Next morning battery was back to 12.6V. As soon has I tried to start the engine battery voltage drop to 10V which means its dead. So I got new battery. But still have issue with current draw from the truck. So before putting the new battery I needed to find out what was draining the battery. So I disconnected the positive cable from the battery post
I connected my amp meter between positive post and the positive cable. With the truck turn off I could see that the truck was drawing between 1amp to 5 amps. It was going up and down. Now I knew why my battery was dead. While watching and amp meter I started to pull out fuses one by one from my fuse box located under the hood. Once I pull out the starter relay the current draw on my amp meter decrease to 0.4amps and it was stable. Problem solved. Put back relay in the fuse box current stayed the same 0.4amps. Put new battery and clear engine light with OBD scanner. All good now. Battery is staying at 12.6V now after 24 hours.

 

[Atcer2018]

FIX IT
I had the engine code P1DF3 on my 2019. Battery was dead only had 10.8Volts. So I disconnected the battery cable and charge the battery over night. Next morning battery was back to 12.6V. As soon has I tried to start the engine battery voltage drop to 10V which means its dead. So I got new battery. But still have issue with current draw from the truck. So before putting the new battery I needed to find out what was draining the battery. So I disconnected the positive cable from the battery post
I connected my amp meter between positive post and the positive cable. With the truck turn off I could see that the truck was drawing between 1amp to 5 amps. It was going up and down. Now I knew why my battery was dead. While watching and amp meter I started to pull out fuses one by one from my fuse box located under the hood. Once I pull out the starter relay the current draw on my amp meter decrease to 0.4amps and it was stable. Problem solved. Put back relay in the fuse box current stayed the same 0.4amps. Put new battery and clear engine light with OBD scanner. All good now. Battery is staying at 12.6V now after 24 hours.View attachment 541914

Nice work troubleshooting.