What happens when you leave your key in the ACC position ?

[Charlie W]

Had a weird one at deer camp this weekend. Came back from deer blind and buddies said, hey your bed light has been flashing on and off, went and looked and windshield wipers were stuck halfway across windshield. Had no power anywhere, not even a dome light. Noticed that key fob was in accessory position.
Put it on a trickle charger, cause I am still running original OEM battery on my 2018 Ram PW. Thought maybe it was already time to change it.
Finally jumped it with a buddies truck, started pretty easy after about 5 minutes. Then check engine light came in. Went to town and battery tested good, but still check engine light was on. No one had a code reader, tried the old 3 clicks on and off with key fob, but didn't display code like my older ram did. Anyway to get codes without a scanner on these newer trucks ?

Anyway, thought it was weird for a low battery. Check engine light eventually went off and truck ran great 165 miles back home pulling an 8000 lb. Travel trailer.
On another note, used tow/haul on way to camp, averaged 6.3 mpg. Did not use tow/haul on the way home, average was 7.8 mpg. When using tow/haul, frequent downshifting even on little hills. Was wondering what the hill assist does and would it have helped ?

Pardon my rambling.

 

[IRSmart]

Your check engine light is on because the system detected low voltage. It will go away.

Tow haul changes the shift maps, holds gears longer to help control gear hunting, downshifts during deceleration to assist in engine braking, and eliminates overdrive.

 

[Overlander]

I'm a big fan of using manual shifting modes when towing. Tow/haul can't see hills in front of you and won't manage energy in the way that supports transmission longevity. It just lock onto the set speed and does whatever it needs to keep that locked on. On rolling hills I like to hold an accelerator position that will keep the TC locked in the current gear and accept some variation in speed. I will also take a higher RPM in a lower gear consistently while pulling a grade than allowing the box to follow its map. Goal is to keep the TC locked to avoid heat buildup and keep the shifting to a minimum. This won't help you fuel econ, but it will affect your longevity.

 

[Jeff Strader]

Simple, your battery dies if left on too long.

 

[retired]

The check engine light will go away if there are no more codes or the code resolved it self after a certain number of off on cycles with driving and down time factored in.

 

[Trailmaker]

Had a weird one at deer camp this weekend. Came back from deer blind and buddies said, hey your bed light has been flashing on and off, went and looked and windshield wipers were stuck halfway across windshield. Had no power anywhere, not even a dome light. Noticed that key fob was in accessory position.
Put it on a trickle charger, cause I am still running original OEM battery on my 2018 Ram PW. Thought maybe it was already time to change it.
Finally jumped it with a buddies truck, started pretty easy after about 5 minutes. Then check engine light came in. Went to town and battery tested good, but still check engine light was on. No one had a code reader, tried the old 3 clicks on and off with key fob, but didn't display code like my older ram did. Anyway to get codes without a scanner on these newer trucks ?

Anyway, thought it was weird for a low battery. Check engine light eventually went off and truck ran great 165 miles back home pulling an 8000 lb. Travel trailer.
On another note, used tow/haul on way to camp, averaged 6.3 mpg. Did not use tow/haul on the way home, average was 7.8 mpg. When using tow/haul, frequent downshifting even on little hills. Was wondering what the hill assist does and would it have helped ?

Pardon my rambling.

I a lot of times once an older battery gets completely depleted it will lose cranking amps and will not be dependable. If you can service your battery, then check it to see if you need a little water. But be on the prowl for a new battery since most OEM batteries (for me) last 3-5 years. The light should stay off if the alternator is available to keep up. Normally puts out 13.8-14.1volts.

tow/haul will save your transmission from over heating and also does not allow it to go in to o/d in most models. That is why you saw less mpgs with it on. It will also keep MSDS (eco) from coming on.(4 banger mode)

Hill control is for being stopped on a a incline. The system gently activates your brakes enough to keep you from drifting backward when you remove your foot from the brake and move to the accelerator.

Hill decent control is totally different. Like Cruise control for rock crawling down hill

 

[Daw14]

If I’m not mistaken hill assist prevents the truck from rolling backwards when starting on an incline.

 

[BWL]

To answer your question the battery will die eventually. Depending where you are, your level of survival skills and whether or not you have the means to recharge it you may die as well. Maybe I should get a solar battery tender.

 

[SeppW]

Need to carry one of the battery booster/jump start like NOCO, Schmacher, etc. They're pretty handy and hold a charge for some time. I had a NOCO and the damn thing went tango uniform for some reason. I had left in the truck and I assume the temp spikes between summer and winter killed it. Now I don't leave it in truck unless I'm in it, otherwise I keep it house where temps are fairly steady.

 

[ALRedneck]

Ditch the extra mile per gallon and use tow/haul mode. With 8,000 lbs, I personally lock it in 4th and will manually downshift to 3rd if needed. This prevents the hard downshift from 4th to 2nd which drives me crazy. I have the six speed so may be different with the 8 speed.
My hill descent keeps you at a slow, steady down hill speed. Think max speed is around 10 MPH. Mine only works in 4x4 or at least that’s the only way I could get it to work

 

[Grand Mesa]

Your battery should still be fine.

I still have my OEM battery in my 2016 and it should/might/could still start the truck in cold weather even at the "operation not recommended" temperatures.

Come winter that's when you'll know for certain.

Lead-acid batteries...

 

[Travelin Ram]

When the integrated power module started to go out in my 2011 it did strange things like activate the wipers or beep the horn with no input from me.

 

[Charlie W]

Thats what I was worried about initially. Thought computer was croaking. At least it would have been under warranty, I think.

 

[BWL]

Your battery should still fine.

I still have my OEM battery in my 2016 and it should/might/could still start the truck in cold weather even at the "operation not recommended" temperatures.

Come winter that's when you'll know for certain.

Lead-acid batteries...

View attachment 228335

Looks like I use mine when not recommended an aweful lot.

 

[RamCares]

Thats what I was worried about initially. Thought computer was croaking. At least it would have been under warranty, I think.

Hello @Charlie W
We are relieved to hear that your concern seems to be resolved at this point. If you face any reoccurring concerns down the road, please feel free to send our team a private message for support alongside a dealer visit.

Kathryn
RamCares

 

[62Blazer]

For the battery, as mentioned above if you leave the key on it will drain the power from the battery. Though I will say most newer vehicles have timers or sensors where they will automatically power down the vehicle if you do this. For the engine light it was detecting a low voltage situation. If you jump start the vehicle the alternator will take over but it will take awhile for the battery to charge back up.

On the fuel mileage I wouldn't attribute the difference because of the tow/haul mode as there are a lot of other variables going on. You may had a head wind going there but a tailwind on the way back, on average you could of been going uphill in one direction and then downhill in the other direction, or simply the weather conditions were different (different amounts of wind, different temperatures, etc...).

 

[BlueGuyRedState]

Your battery should still be fine.

I still have my OEM battery in my 2016 and it should/might/could still start the truck in cold weather even at the "operation not recommended" temperatures.

Come winter that's when you'll know for certain.

Lead-acid batteries...

View attachment 228335

Just had the OEM battery replaced under warranty in our 2018 RAM 1500 during first cold snap in rural Nebraska. Went from working to stone cold dead. Purchased Certified Preowned so it passed dealer's inspection once anyway.

Have seen on RAM Forum references to some 2017-2019 (Classic) OEM batteries crapping out prematurely. Just retired from 20+ years as a computer tech, battery manufacturers can have bad production runs where the problems take months or even a year or two to appear. At least the RAM ones don't burst into flame!

 

[SeppW]

Just had the OEM battery replaced under warranty in our 2018 RAM 1500 during first cold snap in rural Nebraska. Went from working to stone cold dead. Purchased Certified Preowned so it passed dealer's inspection once anyway.

Have seen on RAM Forum references to some 2017-2019 (Classic) OEM batteries crapping out prematurely. Just retired from 20+ years as a computer tech, battery manufacturers can have bad production runs where the problems take months or even a year or two to appear. At least the RAM ones don't burst into flame!

Cold weather is a battery killer.

 

[Grand Mesa]

Cold weather takes a double whammy on the power supplied and the power needed.

 

[Digger Dan 188]

As I've been told by a battery guru- the hot weather is the culprit that does the damage to the battery. However it shows up in the cold/winter weather due to the increased demand for amps on cold start. I thought this was a line of houie, but I had a Buick Riviera that had the battery under the backseat, not in the hot ass engine compartment. That OEM battery lasted right at 6 years!! The best I have gotten with batteries under the hood is 2-3-1/2 at best. So based on this experience I figure he was right.

The batteries in the HDs (not sure about the Hemis) have a "blanket" around them to try to insulate them from some of the under hood heat. I'd bet good money theyre trying to make em last to 36,001 miles or 37 months to avoid having to replace them under warranty!

Be Safe out there folks!!