Dash lights up like a Christmas tree

[MattK67]

I have a 2015 Ram 1500 that started with electrical issue I believe. At least 3 months ago when starting the truck I began having an issue where after the dash lights complete their "test", just about all of them would come on and stay on. It'***** and miss when I start it. Sometimes they the issue pops up, sometimes it starts normally. When in this error state, the gas pedal won't function, after a few seconds it will start to idle a bit rough. If it goes into this error state, if I shut off and restart eventually it will start normally without any lights or issue. It may be one time, it may have to be a few times. Back in November, before this started, I had a MIL light (P2681) that read as a engine coolant bypass valve circuit open. I thought it to be a bad valve and changed it with a NAPA replacement. The MIL light went out for about a week and then returned with that same code. About 3 weeks after, this new issue started. I'm not sure if the valve one was related to the current issue. I tried to research the current issue and thought maybe a bad ground. I went to all the grounds I could find and cleaned them with no resolve. I figured I'd take to the dealer to troubleshoot and after 2 hours time they said the grounds were good that it was the PCM. They quoted $1600 for the PCM + labor for them to replace it. I took it home and ordered a PCM from Flashmasters and replaced it with no fix. Speaking to another mechanic it's felt it's not a ground issue because if it starts normally, it won't go into this error or failure mode while driving. At least not yet. He felt it seems to be something not starting/turning on/powering up as it should all the time. Sort of like a sticky relay or something. I have seen that the Rams have a potential for a TIPM failure and he suggested that might be the next step. Could the BCM be the culprit? Or I hate to think there is a wiring issue hidden somewhere. The truck underneath is pretty clean with very minor corrosion for the year so I may be wrong but am leaning toward the wiring being ok.
I am hoping to get thoughts of you all that have more experience or have heard of this issue/fix. I'd rather not just keep throwing parts at it blindly. Attached are some photos of a few of the warnings that come across the dash, but there are several more including service air bags, trailer wiring, etc. that I didn't include. The codes are from a few different times. They are generally the same when they come back after I clear them.




Thank you for your thoughts or ideas!

 

[Daw14]

Often times when our truck light up like Christmas trees , it is the battery that is going out .
Have it tested with an old style toaster type tester, this puts it under load for testing, a dvm will not load the battery as needed .
These testers are about $20.00 at hobo frait.

 

[Ken226]

While the battery is a possibility, usually the codes are "lost communication with x, y or z". Your codes all seem to be "intermittent circuit high" or just "circuit high".

All of those unrelated systems showing "circuit high" faults strongly indicate an open circuit somewhere. Somewhere that powes a lot of different stuff.

The old saying, "powers and grounds". In your case, look at fuses, wires and connectors. Check all the big fuses.

Check the big connectors at the BCM, PCM and TIPM for corrosion and damage. (Looking from the outside doesn't accomplish jack ****. Unplug and look in the connector).

If nothing, then

Get a wiring diagram (there are threads with links to the service manual -search-), look for wires and connectors that are a common power supply to these sensors showing faults.

Then inspect grounds that are shared by those same fault systems/sensors.

Because "circuit high" means there is voltage in the circuit that's not being pulled to ground when it should be.

 

[Ken226]

I see that your in snowy, salted roads PA, just coming out of winter months. Even more reason to look inside the plugs and connectors (especially the underside of the TIPM) for corrosion.

Test the battery, like Daw mentioned above first, as that is low hanging fruit. But when that's done, grab a flashlight and a creeper.

 

[Daw14]

There is a large connector behind drivers tire under the inner fender liner. This oftentimes gets some of that corrosion, be patient there are lots to look at.

 

[MattK67]

Often times when our truck light up like Christmas trees , it is the battery that is going out .
Have it tested with an old style toaster type tester, this puts it under load for testing, a dvm will not load the battery as needed .
These testers are about $20.00 at hobo frait.

Thanks for the reply. I knew I'd miss something. I did check the battery, it was a 36 month battery at about 5 years old. It was still testing ok, but I figured it was time to replace it anyway and replaced it. Unfortunately no change with that either.

 

[MattK67]

Thanks for all the replies!! It certainly is giving me some direction. I did unseat and reseat the connectors for the TIPM, BCM, and , PCM when I replaced it but I didn't really visualize them well to look for corrosion. I will have to go back and do that. Certainly also will look for the one behind the driver's tire. I agree, I'm sure a lot of crud get slung up there. I will have to look for a service manual as you mentioned. Hopefully I will find something with the connectors, but I'll have to start tracing in the schematic in case the plugs are also a dead end. I'll reply back with results although I may not know for a while. Used the truck today to go 1 1/2 hr. one way and no issues with the multiple starts. It seems to happen when you least expect it. Thanks again for the tips and information!

 

[Ken226]

Here are 3 sensors that have fault codes, that all share a common sensor ground. The circuit K915 Pin20, brn/white all go to the common splice SP1725.



SP1725 is here:



So, i'd inspect the wiring harness in that area, and look at nearby grounds


I'd bet that some or all of the other systems showing fault codes have grounds that pass through that splice, and use the same ground location.