I've read a lot about this problem and still haven't read of a definitive, consistent cause of the problem. truck dies and starts itself right back up going down the road when it's cold out. except this time it died and it would crank but wouldn't start back up. I replaced the batteries on the side of the road and it fired right up. was fine for a day and then tonight, 23 degrees out, dies 3 times. I already cleaned and tightened every ground I could find, 2 brand new Optima red tops installed. before I finally give up and take it to the dealer, is there anything else I can do?

 

Since you recently replaced the batteries,remove and clean any corrosion from the cable ends(terminals) including the battery (Grounds off first). Then use a wire brush to clean the cable ends and battery terminals. Re install and tighten the terminals (ground cables on last). Make sure to take notice if you see any corrosion under the rubber jacket on the cables where they meet the lead connectors. Corrosion inside the wires can cause issues.

 

One thing you have to watch for is having the cables clamped tight enough on the posts. I have found that non OEM batteries require you to tighten the cable ends down to keep them from moving around on the posts. I believe the OEM batteries have posts that are larger diameter than other batteries. Make sure the clamps are tight and not causing a loose connection.

 

I've had the cables off a dozen times on 2 sets of batteries, I load tested the first set and they were good but since they were original and 7 years old I replaced them. cleaned the posts repeatedly and tightened them down till the wrench slipped. when it died it had plenty of cranking power but no power to the ECM.

 

How did you determine that there was no power to the ECM?

You really should check for corrosion inside of the cables no matter how many times you removed and replaced the cable ends on the batteries.

I have attached the diagnostic data sheet for the p2509 code for your review.
I recommend you also check the ECM ground wire to engine from C2 on ECM wire harness to G114 ground point. Three grounds come out on 3 pins from C2 connector then join into 1 ground wire.

 

I tried cycling the key 3 times several times and codes would not display, check gauges light was on, engine would crank fine but not start.

can I order a set of new cables from the dealer? thanks for the help.

 

Yes. The dealer can get new cables,however; they are expensive.

 

I know there are many different things it could be and to check for, but I had the same issues in my 06 mega and after a couple weeks of testing and searching different possibilities (at a dealership and then a diesel shop) it ended up being the ECM itself.

 

I tapped the clamps on tighter with a brass hammer and really snugged the bolts up, hasn't acted up since, though it hasn't been quite as cold.

 

yeah so it's been acting up again, took it to the dealer, they said dirt in the fuel rail is making it die. this makes no sense, does not explain the check gauges light or the failure to start when it died. in other words they can't diagnose the problem.

 

If the problem can be duplicated, disconnect the fan clutch 6-way connector and check if the concern still occurs. Connector is located bottom of fan shroud, If the problem no longer occurs, replace the fan clutch assembly.

 

I put in everstarts back in dec 2012 and had to use a cut off wheel to cut the battery cable clamp as so they close a little tighter. work great so far nice and tight

 

I recently had a similar problem. The ground cables to the ECM on the driver's side battery were severely corroded and finally broke off. The truck would crank but not start and a "No ECM" (I think) code was displayed when I did the on-off (3x) sequence.

The root cause was a leaking negative post on the drivers side battery.

 

my 03 has done this 2 different times. once on a trip to texas 2 years ago... kept "blinking" out, as tach and spedo drop to zero for a split second then right back to normal and the engine actually dies for that split second. Did it about 30 times on that trip but started fine and while annoying it got me home. I did have 2509 code so I cleaned all terminals and put in one new battery then, but it still acted up after all that. Then I drove 2 years around home with no long trips more than an hour or 2 and no issues at all. So I took it to Georgia and about 9 hours into trip it starts doing it again. I again took off all terminals and cleaned and had batteries tested at Oreilleys auto parts and both load test good. But it blinks out.... sometimes it did it 3-4 times in a row and then go 100 miles without doing it. Then once and 40 miles without.... Then it really got bad, did it 8-10 times in a row and really never wanted to run right so I got off interstate at a truck stop and let it sit overnight. When I started it in morning it fired right up and blinked once idling and tried to leave it wont run 2 seconds without doing it... multiple times in a row so it still sits at truck stop cause I didn't wanna get stranded on interstate. I did recheck all grounds and battery terminals again and its all good. I'm waiting for a buddy to come tow me home. Gonna get home and try to figure it out, I hope it isn't the ECM but if so does anyone have one off eBay that is "REBUILT" FROM ONE of those places??? JUST wondered if they were any good.

 

and I watched it real close, the EDGE display doesn't blink out.... just tach and speedo, the other gauges don't seem to do it either.