Dead battery on a 6.7 Cummins question

[Hudson]

Quick question for you diesel guys
Does the 2500 6.7 throw a CEL when the battery is dead and you start to start the truck?

Greatly appreciate the insight

 

[mtnrider]

I haven't personally seen it but I am sure it's possible. These trucks do weird things when the batteries die. If you are unsure go get them load tested. 3 years +/- is about average lifespan for them in these trucks

 

[Hudson]

Thanks. Reason for asking is I went to see truck I'm looking to buy at the dealership today. they couldn't start it so they jumped it with a battery pack. Then i saw the CEL and the sales person assured me it because of the dead battery. We shall see when I go back on Friday.

I wonder if the 2018 2500's require the security bypass module like my 2018 1500. Would love to hook up my alfa OBD to this truck and read the codes.

 

[BossHogg]

Thanks. Reason for asking is I went to see truck I'm looking to buy at the dealership today. they couldn't start it so they jumped it with a battery pack. Then i saw the CEL and the sales person assured me it because of the dead battery. We shall see when I go back on Friday.

I wonder if the 2018 2500's require the security bypass module like my 2018 1500. Would love to hook up my alfa OBD to this truck and read the codes.

A lot of the DTCs will be "lost communication" with some module. Those would go away once the engine was running after several minutes. Pay attention to any code stored in history. They will not trigger a cluster light (unless the cause is present) but will show up on the dealer's scan tool. Codes stored in history will disappear as long as the cause is gone and after a pre-determined number of ignition cycles.

Since the vehicle's electronics never completely fall asleep, for example, the RF Hub, which wakes up periodically to sniff for its FOB signal, will drain the batteries after several weeks of the truck sitting idle. If you like the truck, have the dealer install brand-new batteries.

 

[nlambert182]

What he said...

And YES, the 2018 2500 still requires the same security bypass cable as the 1500.

 

[Dean2]

You don't need the security cable to just read stuff, only to make changes. Plug in an MX+ and it will show you the stored codes, even without using AlphaOBD. The MX+ has very good diagnostics built into its proprietary APP. If you want to dig deeper link your Alpha and look at it too.

 

[62Blazer]

It could throw a code, but it's not guaranteed to. Haven't personally looked at a Cummins truck but my 6.4 Hemi powered truck has had a dead battery a couple of times where I had to jump it, and it never set an engine code. Have dealt with dead batteries and jump started many other vehicles over the years and rarely see a check engine light after getting them running. Again, it's quite possible the code is from the dead battery but not guaranteed. The newer the vehicle, the more of a possibility that is. We have '14, '16, and '20 model year vehicles of different makes at our house and every one has had a dead battery and some point in time and a battery replacement, and have never had to clear out a fault code because of it.

It's really not that hard to put a scanner on it and check the codes. The only reason a dealership would have an issue is if maybe the service department was not open at that time.

 

[Hudson]

What he said...

And YES, the 2018 2500 still requires the same security bypass cable as the 1500.

I got mine form KAODTech. Are the interchangeable between 1500 and 2500?

You don't need the security cable to just read stuff, only to make changes. Plug in an MX+ and it will show you the stored codes, even without using AlphaOBD. The MX+ has very good diagnostics built into its proprietary APP. If you want to dig deeper link your Alpha and look at it too.

Good to know. Did not realize that

A lot of the DTCs will be "lost communication" with some module. Those would go away once the engine was running after several minutes. Pay attention to any code stored in history. They will not trigger a cluster light (unless the cause is present) but will show up on the dealer's scan tool. Codes stored in history will disappear as long as the cause is gone and after a pre-determined number of ignition cycles.

Since the vehicle's electronics never completely fall asleep, for example, the RF Hub, which wakes up periodically to sniff for its FOB signal, will drain the batteries after several weeks of the truck sitting idle. If you like the truck, have the dealer install brand-new batteries.

Yup, the salesman assured me 2 new batteries. Since i don't believe them i took pictures of the current ones in the truck and we will see

 

[turkeybird56]

Cannot speak for 6.7, but on my 2019 Hemi, when battery was going bad, it threw 42 codes (codes and sub codes), most associated with low voltage issues, ie., Dead Battery. Got mil light, once new battery in, all cleared within a couple of drive cycles. It did take 4 drive cycles till my Cruise came back.

 

[nlambert182]

The bypass cable is interchangeable.

 

[Hudson]

The bypass cable is interchangeable.

awesome thanks for confirming

 

[stevenP]

My OE batteries lasted 5 years, and didnt fail just cranked the engine a lot slower. Never had CELs, but mine also didnt fail to start. I also keep my truck on a battery tender when not in use to help extend my batteries life.

 

[nlambert182]

My 3500 batteries lasted almost 5 years before they gave up the ghost. No slow crank, no CEL, nada. We were at a campground and it just didn't start one morning. Thankfully we also had the wife's car so I was able to jump it and drive to the part store to swap them.

 

[turkeybird56]

My 3500 batteries lasted almost 5 years before they gave up the ghost. No slow crank, no CEL, nada. We were at a campground and it just didn't start one morning. Thankfully we also had the wife's car so I was able to jump it and drive to the part store to swap them.

THATs wat I hate about these new systems. You used to get like some type of warning, when battery going. NOT anymore, 1 day good, next day BLAM !!!!! Gotcha.

 

[DodgeDude99]

I have a 2014 2500 6.7, replaced the batteries in 2018 & 2023. It’s always the driver side going bad.

 

[nlambert182]

4-5 years... sounds about right. Both batteries are wired in parallel so they technically share the load "equally", but the bigger cables are on the driverside closest to the TIPM, so there is a chance that it has a slightly larger load than the passenger side and is likely to have more current draw from it.

 

[Hudson]

i am happy to say the the CEL was due to the dead batteries. The dealer installed 2 new Mopar batteries and the CEL went away after a short test drive

 

[oe542bob]

Hudson, I had an ‘18 Limited 2500 CTD I purchased new. Had the truck almost 4 years, traded it in with +/- 120,000 miles. Weird to me about the CEL you saw. I actually carried a NOCO jump box with me, because any time if I sat listening to the radio, for let’s say a couple of hours, I would have to jump it.
Once the voltage would drop below 12, it wouldn’t start, or even try. I never had a CEL come up with this scenario.

 

[Dean2]

i am happy to say the the CEL was due to the dead batteries. The dealer installed 2 new Mopar batteries and the CEL went away after a short test drive

What code was set with the CEL? You can pull the code with a simple OBD reader. The fact the CEL cleared may have nothing at all to do with the new batteries. Since this is a used vehicle you are buying I would want to know positively what caused the CEL before laying my cash on the table.

 

[Hudson]

i was too late for that. OBD only told me that the CEL was cleared when the batteries were replaced.