So I've been searching here for the p2509 code but I haven't seen anyone with the exact situation...

I had my truck sitting for months without cranking it over and when I tried to fire it up it was completely dead. I tried charging it for what seemed like hours and finally got it to crank over! I drove it around for about 30 minutes and when I parked it and tried to instantly crank it over if wouldn't budge again. So I changed the batteries and ever since then I've had the p2509 code. I've checked the clamps and they are tight to the terminals. There's no corrosion on the terminals either. I get 14 volts to both battery harnesses while truck is running so I think the alternator is fine. I've read about the ECU cabling and possibly a grounding wire not be connected well but I'm not sure where those locations are.

Any help would be great.

make sure all grounds are secure , clean and tight

 

So I found 4 ground cables going to frame and even volt tested 12v to bolt with ground wire and had 14vdc on each one. Not sure what else to try here. Anyone?

 

Check grounds on ds fender and ECM itself.
check B+ lug on side of PDC that feeds ECM battery power, wire has fusible link and then spliced/splits off to ECM c1 connector, pins 20,30,40 should have same voltage as ds battery.
Newbies guide has FSM with wiring diagrams here

Newbies guide to your new to you truck

First off welcome to CumminsForum! Lots of smart guys here that have seen a lot. VIN Lookup... https://www.cumminsforum.com/threads/newbies-guide-to-your-new-to-you-truck.1909713/page-11#post-29385439 Service Manuals (PM me if the link is not working, use Adobe to open them) Updated Links...

www.cumminsforum.com

 

Hey bud, I really appreciate the info (even download the 04 RAM manual and bookmarked the forum convo), but I have tried to do what you've recommended, but don't understand a few things.

Where is the ground to the ECM itself?

I don't see a "fusible link". (is B+= Battery positive?) I do see the power going to the two ECU connectors.

Is this the B+ that feeds the ECM?

You said C1 has power on 20, 30 & 40, but I see in the manual that C2 is the connector that has B+ on those.

I am not able to get my voltmeter probs in the wire harness for those connector pins. Am i supposed to remove the harness first? I couldn't figure out how to remove them.

I have tried everything I can, but it all check out fine.

I've tested voltage from battery terminal to wire clamp (for both + & -), I've checked all ground nuts to battery + that I can find (1 DS fender Frame, 1 DS Firewall frame, 1 DS engine frame, 1DS engine block, 1 PS firewall fame & 1 PS engine block) and they all have 12.6 VDC. I've unplugged both negatives for 30 minutes to se if it "resets"... At wits end here!

So, both batteries were purchased from Costco, do you think there could be a problem with one of them? If they gave me a lower cranking amp batteries, would that cause it?

 

My good buddy who is a 20+ yrs Cummins master tech and has seen this code come up and always found the answer was stumped on mine with the same code and symptoms. Stallingg an immediately restarting only to repeat the symptom five miles later at the most. I had an EFI tune in their which worked super but the shop I used has seen Dura's and Rams with the same code. I had it reflashed back to stock and one year later not an issue. I miss that EFI performance though but I'm reluctant to reload it.

 

Odd. mine is a stock tune. Only thing that happened was the truck sat idle for a year and when I went to fire it up both batteries were dead. After O replaced them I got this code...

 

yes should be c2 connector my bad , IIRC grounds are there also 21, 49,50 pins.
section 8w-15 has ground location and info .
ECM case/mount is also ground make sure fastened properly.
yes B+ under that cover , follow that wire should be fusible link then spliced off to feed ECM pins 20,30,40.

Best to disconnect batteries remove ECM connectors look for damage corrosion and check circuits
5 ohm or less resistance on those smaller wires

If good power/grounds
It is possible ECM software got damaged worth checking.
Batteries should be same, typically +750 cca each

 

yes should be c2 connector my bad , IIRC grounds are there also 21, 49,50 pins.
section 8w-15 has ground location and info .
ECM case/mount is also ground make sure fastened properly.
yes B+ under that cover , follow that wire should be fusible link then spliced off to feed ECM pins 20,30,40.

Best to disconnect batteries remove ECM connectors look for damage corrosion and check circuits
5 ohm or less resistance on those smaller wires

If good power/grounds
It is possible ECM software got damaged worth checking.
Batteries should be same, typically +750 cca each

So ECM Case/Mount look fine... The ECM Connectors also looked fine, but I don't know where I would be testing resistance to on the circuits? Are you saying test 21, 49, 50 resistance to ground and those should have ~5 ohms?

If the ECM software got damaged how to I get that re-flashed? do I have to take it to the dealer???

Thanks for the info!

 

Really need to look in FSM, I am going by old timer memory.
IIRC, those are C2 connector cavity numbers for grounds.
section 8w has index shows ground and power locations in individual sections
ECM has multiple of each
voltage test batteries voltage, that number , 12.6+ volts =good battery, should be same +/- 0.2 volts on large cables and same on smaller wires, any where B+ circuit goes , if not cable/wiring are suspect.
Proper voltage testing and proper resistance are all discussed in FSM 8w .
When resistance testing for good ground, need to be isolating circuit, meter zeroed between test , at which point grounds tested to battery negative should be less then 5 ohms.

2003-05 trucks ECM reflash is by dealer or can try contact tuner ie Smarty get a recovery tune .
ACS vendor on here can also perform if you send your ECM to them
can contact them, look on vendor forum