Warning light illumination unavailable - service required

[HudsoTodd]

damn...I mean, Im down to not drive my truck and put miles for more than a month if in return I get 5k and extended warranty haha...this is of course, IF they were making your payments and got you a rental for free.

I know right, they did give me a rental. But the first truck had to be towed off my driveway .

 

[HudsoTodd]

Take the money and run. Makes me wonder if your truck has to be down for awhile for them to do that or if my 7 trips to the dealership and over a week without truck would be sufficient. Fkn ram .

Did you open a case with RAM

 

[RAM-Ranch-MT]

Did you open a case with RAM

Negative, if it doesn't get fixed with my visit in 2 weeks ill open one. Seems like a hassle. What's the best channel to go through to get ahold of them and take you seriously?

 

[HudsoTodd]

Negative, if it doesn't get fixed with my visit in 2 weeks I’ll open one. Seems like a hassle. What's the best channel to go through to get ahold of them and take you seriously?

With my experience I had to open the case with RAM customer service over the phone. Then I was given a case manager. To make the process easier, tell the case manager your experience, and ask for a retention manager. The retention manager is where compensation happens.

 

[70runner]

RebelX owner - I come in peace

Bought it a month ago, drive home (150mi) everything perfect. Only driven once since, installing camera, powersteps, trailer winch wiring, also out of country for a bit. Yesterday, while troubleshooting powersteps (story for another day), got the warning light illumination unavailable along with service trailer braking system messages. Battery check, 11.5v. Put it on my charger overnight and drove it today - no warning/service messages. Cause is, as some have speculated, apparently related to battery charge condition.

 

[HudsoTodd]

RebelX owner - I come in peace

Bought it a month ago, drive home (150mi) everything perfect. Only driven once since, installing camera, powersteps, trailer winch wiring, also out of country for a bit. Yesterday, while troubleshooting powersteps (story for another day), got the warning light illumination unavailable along with service trailer braking system messages. Battery check, 11.5v. Put it on my charger overnight and drove it today - no warning/service messages. Cause is, as some have speculated, apparently related to battery charge condition.

I have not found anybody with the service trailer braking system issue. Just got mine back from the shop for almost 50 days and of course this light comes back on… going to check the battery now! Update: my battery is at 14.1 V so I don’t think that’s the issue!

 

[toast411]

Does anyone have an actual proven connection between battery condition and the 'warning light illumination....' error?
Asking as many posts assert they are connected.

 

[MattH89]

RebelX owner - I come in peace

Bought it a month ago, drive home (150mi) everything perfect. Only driven once since, installing camera, powersteps, trailer winch wiring, also out of country for a bit. Yesterday, while troubleshooting powersteps (story for another day), got the warning light illumination unavailable along with service trailer braking system messages. Battery check, 11.5v. Put it on my charger overnight and drove it today - no warning/service messages. Cause is, as some have speculated, apparently related to battery charge condition.

 

[Metallikahn]

Just brought mine home and at 1500 miles I got this message last night when we left the in-laws to head home. 30 minute drive on the highway home and it was still showing when I turned it off. Let it sit for a minute and started it back up. Still had the message, so I parked it and went inside to take care of a few things before going out and hooking up the Noco Genius5 tender. I started by testing the volts on both batteries and they were both at 12.9. Hmmm… hooked up the tender and within a minute or two it was green and saying full charge. Hmmmmmm… climbed in and the message was gone. Started the vehicle and still no message. Left the tender on last night and so far today, no message.

Sooo… here’s my theory. I spent yesterday adding mods: running boards, dash cam, and a boost converter for my Starlink mini. That last one is important. The way I wired it in was so that the Starlink only gets power when the ignition is on. I’m still waiting on an extension cable, however, so I’ve just been plugging it direct into the 12V outlet on the dash. We were at the in-laws for a couple hours and guess what I forgot to unplug? FWIW, the truck started just fine when we went to leave and there was zero indication the battery might be low, other than this warning message.

So, I don’t know where the threshold is for this message to trigger, but it’s likely a fair bit higher than the minimum voltage needed to spin the starter. Also, once charged back up via the alternator, it might take 10-15 minutes for it to fully clear after everything is off. Other than the message I noticed absolutely nothing else out of the ordinary. Can safely say with 99% certainty it was battery related in my case and 100% due to me leaving my internet plugged in with the engine off.

 

[HudsoTodd]

My truck is back in the shop. The “service trailer braking system” light came on right after I got it back. The dealer told me they have never seen this truck and are not sure how to diagnose it. Truly annoying.

 

[NYRHO]

Just got mine back from service a few days ago for the exact same issue. The first time it happened to me was a week into owning. The " warning light ilumination unavalable" light came on with 200ish miles and I bursted into laughter. For reference I never buy a car/truck. Ive always loved the idea of leasing. Recently my leases had gotten out of hand and always tried to get out of them every 6 months or so...so I figured time to be a grown up and buy something I love and commit to it, no more breaking leases every few months. Shocked that this happened after only 200ish miles. This exact message popped up a few times but always went away the next time I would start the truck. Called and booked an appointment with my service advisor and when I pulled up for the service they plugged in the car right away and showed me 8 different faults that came up through out the 1800 miles I've driven in the last 3 months of ownership. Great just my luck...I finally buy something and it's already broken after only 2 months. 1 week later and my service advisor calls me telling me that all the faults showing were just glitches. They checked every one of the faults and according to them its not electrical but rather the cluster is receiving or sending false reads and that's why the code never lasts pasts a few seconds of either the car turning on or the car turning off. Cluster was swapped out and have had the car a few days and about 200 miles no issues at all. I know its too soon to tell but ill deff keep you guys all posted. Seems like the cluster has a mind of its own.

 

[Faze]

I'm waiting for dealership to receive new brake booster and once I put it in shop they will fix the software.. not sure what they did, the issues started when I asked them to activate the "automatic door locking", once I sat in the truck all cluster settings were set to default etc.. think they messed up .. unless the cluster is bad and it's just coincidence

Update. Software flash didn't work. Getting new cluster, 7-14 days waiting time. If this is how it's going to go in the future I will have a brand new truck out of all these new parts brake booster is on backorder everywhere so they can't even tell me the ETA on that

 

[BLKRHO2169]

Update. Software flash didn't work. Getting new cluster, 7-14 days waiting time. If this is how it's going to go in the future I will have a brand new truck out of all these new parts brake booster is on backorder everywhere so they can't even tell me the ETA on that

Could set the Automatic Door Locking thru Witech on mine at all. Felt dumb like I couldnt find it.

Going to have to try using CDA instead... Also after 250 mile trip today just as I pull into the hotel I get the warning Illumination light fault. Batt Voltage showing 13.7.

Turn off, and cycle ignition... Gone... Like usual.

 

[jamoke]

Just picked up my 2026 Ram 1500 Big-Horn on Tuesday. Noticed this error on delivery and the sales lady just said "It's probably from them prepping the car with a software update." I was suspect of it. Anywho, 3-days later (about 270-ish miles) and it came on at start again. At this point, just seems cosmetic and nothing functional (at least from what I can tell) is broken.

I do wonder if any options could be part of this. I do have the upgraded Alpine sound-system. I also have been using the Auto-Engine Shutoff at stop lights (trying to get the most out of my 20mpg rating).

Calling dealer in the morning. I reluctantly am now part of this non-elusive club.

 

[toast411]

Just picked up my 2026 Ram 1500 Big-Horn on Tuesday. Noticed this error on delivery and the sales lady just said "It's probably from them prepping the car with a software update." I was suspect of it. Anywho, 3-days later (about 270-ish miles) and it came on at start again. At this point, just seems cosmetic and nothing functional (at least from what I can tell) is broken.

I do wonder if any options could be part of this. I do have the upgraded Alpine sound-system. I also have been using the Auto-Engine Shutoff at stop lights (trying to get the most out of my 20mpg rating).

Calling dealer in the morning. I reluctantly am now part of this non-elusive club.

when my truck gives the message; I lose 'some' of the safety features depending upon the mix the error

for example,
sometimes I lose parking assist; sometimes I lose pedestrian stuff; sometimes I lose braking assist

anytime a dealer says "oh, that error is probably from..." in your head, translate it to them just saying. "We have no idea, but please buy this from me today".

 

[hwb1967]

Good morning everyone,

I’m starting this thread as I have searched the forum and haven’t really seen any posts about this warning coming up, unless I overlooked it lol.

This morning as soon as I turned the truck on, I received this warning light on the cluster but I have no CEL on. All my sensors and settings seem to be working fine. Blind spot is working beautifully as well. What exactly is the warning light illumination in question?

Has anyone else had this come up? Could it be battery related? I checked and my voltage is between 13.5-13.7 every day. Not sure if that’s too low that can cause that warning light to come up.

Thanks everyone and hopefully it’s something dumb that I don’t need to go to the dealer for.

View attachment 9939

Picked up my 2025 2500 12 days ago and that message came up. Service manager said once they order a new ( gauge cluster ) i will not be able to drive the truck because it will have to be programmed with the current mileage. Said i will be without the truck 5-7 buisness days and theyll only pay for 5 days of rental cars. WTF

 

[JLM1600]

 

[Mikewhfd]

Brought my 2025 in with the same issue. The dealership said there was a software update. They performed that and I have not had the light reoccur. I’m attaching the report so others can see the resolution to maybe ask your dealership. Apologies for the folded paper picture.

 

[Metallikahn]

View attachment 19406

This is more or less what I expected. It comes up and goes away so randomly and doesn’t seem to have any noticeable effect on the operation of the truck I was like 99% sure it was a software bug somewhere (nothing that ever made me concerned enough to take it in for a new cluster like so many dealers are suggesting as a fix).

Did they give you any idea on whether it’ll be an ecu or infotainment update when released?

 

[JLM1600]

This is more or less what I expected. It comes up and goes away so randomly and doesn’t seem to have any noticeable effect on the operation of the truck I was like 99% sure it was a software bug somewhere (nothing that ever made me concerned enough to take it in for a new cluster like so many dealers are suggesting as a fix).

Did they give you any idea on whether it’ll be an ecu or infotainment update when released?

No, thats all they said. We will see. Mine comes up like once a month…very rare. I have other lag issues with my cluster so they might end up replacing it either way but it wouldnt be because of this message.