2016 1500 5.7 Died, Please help!

[lij1500]

Sorry if this is in the wrong spot, I’m new here. This is my first ram, I bought it a few months ago only and this is the first real issue I’ve ran into, however possibly a big one? I looked for a similar thread and I could not find an instance quite like mine.

Was driving my 2016 1500 5.7 Big Horn today, which has just crossed over 60,000 miles, when it turned off while waiting at a stop light. The dash gave me warnings for check engine light, power steering, passenger headlight, electronic braking system, air bags, and possibly more I’m forgetting. Additionally locked me out of the radio and a red light began blinking on the dash. Even after disconnecting battery for a bit I got no crank/no start. After finding the neutral lock out and towing home I scanned the codes and got U0100, Lost communication with ECM/PCM A. I thought it may be a battery since mine was from 2019 so I bought a new one, got nothing. Tried a new 20A fuse for the ECM, I was able to start it again but it **** itself off again with the same codes about a second later. When I remove and replace that fuse I have been able to consistently start it for that 1 second. Actually, I’ve realized since I started writing this earlier, whenever I let it sit for a little while i can briefly start it as well. Regardless, it now throws a second code U1424. I looked at the connections to the pcm box and they look clean. I believe the AC dumps condensate directly underneath/next to the connections/wires, could that effect it? I’m not seeing any blatant broken/disconnected wires. I am unclear about which way to to go next. I am hoping not to have to take it to a shop/dealer and thinking that someone with more experience may be able to point me in the right direction.

If it is of any worth:
-I recently installed an amp/sub in the truck, but ran it for about a week with no issues until today. I also disconnected power from the amp when the truck initially died and have not reconnected since, and am still having the issue.
-It was a pretty hot day and my car sat in the sun for about 8 hours, but I drove for 30 minutes before the car died and to my knowledge all fluids etc. we’re still in regular operating temps when the issue occurred.

Thanks for any help you can offer!!!

 

[indept]

Welcome to the forum.
Since you're blowing fuses, when you say the Amp is disconnected, is it disconnected at the battery end or the Amp end? You should have disconnected it at the battery end to rule out the Amp power cable shorting to ground. As for the starting and shutting right off, that sounds like the pcm isn't recognizing the fob and the theft circuit is shutting it down. Now if that's the case it could be a bad fob or a fault in the protection circuit.

 

[lij1500]

Thanks for the quick response

I don’t think I actually blew any fuses, just pulled and replaced the Ecm fuse in an effort to possibly reset it. After doing this and I was able to get some kind of response out of the car, I was thinking that possibly the box bolted there onto the firewall may have gone bad? After all, I was getting pretty heavy puddles under my truck due to high A/C use and the air humidity.

And yes, I disconnected the amp power directly at the battery. However, I do still have the amp grounded to bare metal under the driver seat.

I thought the same thing about possibly the fob, so I tried starting the truck with my spare fob as well but no luck. When you say a fault in the protection circuit, is the protection circuit involved with the pcm or is that something separate? And would that cause the multitude of problem messages that my truck is currently throwing at me?

Thanks

 

[indept]

I thought the same thing about possibly the fob, so I tried starting the truck with my spare fob as well but no luck. When you say a fault in the protection circuit, is the protection circuit involved with the pcm or is that something separate? And would that cause the multitude of problem messages that my truck is currently throwing at me?

Thanks

Not sure if it's the PCM or another module, ie the body module, etc. Hopefully a more knowledgeable member chimes in with the answer

 

[Gator Whiskers]

Does it give you all of those same warning lights that it had when it initially died, every time you get it to run for just a second?

 

[04fxdwgi]

On the U1421 code, that is a transmission fault code.

https://www.engine-codes.com/u1424_ram.html

What are the Possible Causes of the Code U1424 RAM?​

• Faulty Transmission Control Module (TCM)
• Transmission Control Module harness is open or shorted
• Transmission Control Module circuit poor electrical connection
• Faulty Powertrain Control Module (PCM)

Would be looking toward the PCM and associated wiring as a start. I would suspect a comms failure. Too much going on on this one.

 

[Sherman Bird]

Sorry if this is in the wrong spot, I’m new here. This is my first ram, I bought it a few months ago only and this is the first real issue I’ve ran into, however possibly a big one? I looked for a similar thread and I could not find an instance quite like mine.

Was driving my 2016 1500 5.7 Big Horn today, which has just crossed over 60,000 miles, when it turned off while waiting at a stop light. The dash gave me warnings for check engine light, power steering, passenger headlight, electronic braking system, air bags, and possibly more I’m forgetting. Additionally locked me out of the radio and a red light began blinking on the dash. Even after disconnecting battery for a bit I got no crank/no start. After finding the neutral lock out and towing home I scanned the codes and got U0100, Lost communication with ECM/PCM A. I thought it may be a battery since mine was from 2019 so I bought a new one, got nothing. Tried a new 20A fuse for the ECM, I was able to start it again but it **** itself off again with the same codes about a second later. When I remove and replace that fuse I have been able to consistently start it for that 1 second. Actually, I’ve realized since I started writing this earlier, whenever I let it sit for a little while i can briefly start it as well. Regardless, it now throws a second code U1424. I looked at the connections to the pcm box and they look clean. I believe the AC dumps condensate directly underneath/next to the connections/wires, could that effect it? I’m not seeing any blatant broken/disconnected wires. I am unclear about which way to to go next. I am hoping not to have to take it to a shop/dealer and thinking that someone with more experience may be able to point me in the right direction.

If it is of any worth:
-I recently installed an amp/sub in the truck, but ran it for about a week with no issues until today. I also disconnected power from the amp when the truck initially died and have not reconnected since, and am still having the issue.
-It was a pretty hot day and my car sat in the sun for about 8 hours, but I drove for 30 minutes before the car died and to my knowledge all fluids etc. we’re still in regular operating temps when the issue occurred.

Thanks for any help you can offer!!!

Can/ Bus malfunction is my first thought, given your recount.

 

[lij1500]

Does it give you all of those same warning lights that it had when it initially died, every time you get it to run for just a second?

Yes it does

 

[lij1500]

On the U1421 code, that is a transmission fault code.

https://www.engine-codes.com/u1424_ram.html

What are the Possible Causes of the Code U1424 RAM?​

• Faulty Transmission Control Module (TCM)
• Transmission Control Module harness is open or shorted
• Transmission Control Module circuit poor electrical connection
• Faulty Powertrain Control Module (PCM)

Would be looking toward the PCM and associated wiring as a start. I would suspect a comms failure. Too much going on on this one.

Can/ Bus malfunction is my first thought, given your recount.

Is it possible to test for these without major diagnostic equipment? I own a multimeter but not sure how to go about doing so. The connections look clean and I’ve looked for broken/frayed wires etc. As of right now I have an appointment for a diagnosis with the local dealer for next week, but if I can get it on my own I’d like to do so

 

[lij1500]

While looking around the engine bay I’ve also noticed that my relay labeled Run/Only clicks on and off every 30seconds to a minute. Is this normal? Or could it be related