Code P2509 and now P0116

[bigceltic]

I wanted to put this on a different thread as my other electrical one is related to my speaker issue - although this is all probably linked.

I have been getting an intermittent P2509 (sometimes a week or two between it and sometimes 2 days in a row) and so I changed my batteries on Tuesday (July 5) - they were 5+ years old so needed to be changed anyway I figure. I cleaned up the terminals when I put them on the new batteries, and the CEL went away on next start. It returned today, however, along with a P0166 and my fan went to 99% demand on the fan and it roared all the way to work. Truck ran fine otherwise. I cleared all codes when I got to work and will see what happens on the way home.

From what I have read, it may be related to the cross over cables. They look fine, no corrosion I can see, but I plan on pulling them and wirebrushing them tonight. The grounds I have checked look fine (no corrosion). Any other tips or things I should look for? I am in CO so I have basically no rust or corrosion to speak of on my truck. Thanks in advance,
George

 

[bigceltic]

I did not get the codes any more today (cleared them when I got to work) and I just got done taking the battery contacts and anything connected to them, and wire wheeling/brushing them until they looked new and then reassembled with dielectric grease. The positive connections (2 wires) on the passenger side battery were a little cruddy but they are sparkling clean now. I also checked all the grounds other than the one to the engine (will have to do that this weekend) - and they looked clean and solid. Fingers crossed!

 

[Topzide]

I'd say other than maybe pulling the coolant temp sensor and looking for corrosion (which should be minimal), if any. Check for secure connection and contact on wire harness connectors. Electrical gremlins are a hard one to track down! You're one the right track with battery replacement and cable clean up. Check alternator output to rule out voltage spikes/drops just to rule it out as an issue. Time is what it will take to find the problem, which is always in short supply! Good luck with this issue. Waiting to hear what you'll find.

 

[bigceltic]

I'd say other than maybe pulling the coolant temp sensor and looking for corrosion (which should be minimal), if any. Check for secure connection and contact on wire harness connectors. Electrical gremlins are a hard one to track down! You're one the right track with battery replacement and cable clean up. Check alternator output to rule out voltage spikes/drops just to rule it out as an issue. Time is what it will take to find the problem, which is always in short supply! Good luck with this issue. Waiting to hear what you'll find.

Thanks! I did notice on the drive today, watching the ECM voltage on my Smarty Touch that it was more consistent/higher - was fluctuating between 14.5xx and 14.7xx (numbers changing too fast!). Also no CEL today! Yeah! Yesterday it was 13.7xx-14.6xx. I will do more tracing/cleaning this weekend. I believe the coolant sensor issue was most likely an electrical gremlin, but I ordered a Cummins sensor and will replace it once it arrives. I will get the alternator tested this weekend as well.

 

[Ozymandias]

Charge voltage is very fluctuating always as voltage and temperature of the battery comes into play.
So to see a difference like yours from one day to another is normal.
But fluctuating should be reasonable in time and not jumping around all over the place.

 

[User113]

Thanks! I did notice on the drive today, watching the ECM voltage on my Smarty Touch that it was more consistent/higher - was fluctuating between 14.5xx and 14.7xx (numbers changing too fast!).

It is silly that the Smarty displays voltages (and other parameters as well) out to the thousandths place. Most of that "numbers changing too fast" is just "noise." Focus only up to the tenths position.

 

[bigceltic]

Update - I drove all day yesterday no issues. Today, I had multiple P2509s, one at a stoplight and the truck died but started right back up. When I got home, I traced all grounds and power lines to and from the battery and pulled all the grounds I could find (IIRC, 3 body- fender, 1 inner fender, 4 engine block) and sanded (emery cloth) and dielectric grease. Will see what happens tomorrow.

One interesting thing - and maybe it is something or maybe not - I disconnected the positive leads of both batteries before working on the grounds and when I put the pass side positive terminal back on, I got sparks, but no sparks with the drivers side positive connection. Does that indicate anything or is it normal. In other words, if I had put the drivers side on first, would I have gotten sparks but not on the pass side?

Yes, I am probably grasping at straws!

 

[brucejohnson]

Update - I drove all day yesterday no issues. Today, I had multiple P2509s, one at a stoplight and the truck died but started right back up. When I got home, I traced all grounds and power lines to and from the battery and pulled all the grounds I could find (IIRC, 3 body- fender, 1 inner fender, 4 engine block) and sanded (emery cloth) and dielectric grease. Will see what happens tomorrow.

One interesting thing - and maybe it is something or maybe not - I disconnected the positive leads of both batteries before working on the grounds and when I put the pass side positive terminal back on, I got sparks, but no sparks with the drivers side positive connection. Does that indicate anything or is it normal. In other words, if I had put the drivers side on first, would I have gotten sparks but not on the pass side?

Yes, I am probably grasping at straws!

Assuming both battery negative terminals were connected, then the sparks are normal for the first positive terminal connection. The circuit became "balanced" (the potential difference diminished) when the first positive terminal was connected. The second positive terminal is now at the same potential as the first (as long as the batteries are close in charge) in a parallel circuit, therefor no "fireworks".

 

[petersonj]

I disconnected the positive leads of both batteries before working on the grounds and when I put the pass side positive terminal back on, I got sparks, but no sparks with the drivers side positive connection. Does that indicate anything or is it normal. In other words, if I had put the drivers side on first, would I have gotten sparks but not on the pass side?

This is a normal occurrence ever since computers were introduced into automobiles. It is even more noticeable with newer vehicles. Computers have the ability to store a small amount of power to keep them in a state of readiness when the vehicle's ignition switch is turned off.

When you disconnected both battery positive terminals, you eliminated the power source to all computers in the vehicle. The computers then drained the small amount of internally stored power while you worked on your vehicle. Then, when you reconnected the first battery, a small, but sudden rush of current went to fulfill those computer's needs. This event would have happened, even if your truck had only one battery.

- John

 

[bigceltic]

Doing some more research, it seems I have a 30 Amp PCM fuse in the fusebox. Is that something that goes bad, or something that might be an issue? I am going pull and reseat it.

https://www.startmycar.com/dodge/ram-2500/info/fusebox/2006

 

[Timd32]

These can be really bad rabbit holes but can't hurt to read it, seems like you have a handle on this circuit might make sense of what they are looking to check.

PDF attached.

There are a bunch of weird Verified Fixes in addition to the below screen shot, so I don't know at times on this thing.

 

[bigceltic]

Hmmm, the info mentions auto trans solenoid... I did notice the positive connection to my BD Tapshift trans controller was a little frayed where it went into the ring terminal, so I cut it and installed a new connector just in case. I am going to take for a test drive today and see what happens.

 

[bigceltic]

Well, I test drove it on Sunday, and then to work and back yesterday and today (30 mi each way) and so far so good! I am hopeful that I solved it - I am pretty sure I got all ground and positive connections other than the one I could see from the trans to the back of the engine (I think that is where it went) - just couldn't reach it from laying on my creeper under the truck. Fingers crossed! Thanks for all the help! It is great to have such a knowledgeable and responsive group here!

George

 

[Ozymandias]

Can't remember to have a ground strap between Motor and Trans, but there is a ground strap between back of Motor and Cab. M6 bolt is roughly in the axis of the flywheel, high above the front drive shaft.

 

[CVR222NV]

Can't remember to have a ground strap between Motor and Trans, but there is a ground strap between back of Motor and Cab. M6 bolt is roughly in the axis of the flywheel, high above the front drive shaft.

Yes back of the motor to the cab firewall. I think I have photos of you need need a reference.

 

[bigceltic]

Can't remember to have a ground strap between Motor and Trans, but there is a ground strap between back of Motor and Cab. M6 bolt is roughly in the axis of the flywheel, high above the front drive shaft.

You gentlemen are probably right - let me look at it tonight. Either way, could not reach it!

 

[bigceltic]

So I think the verdict is problem solved. No codes all week! Lesson learned is that those contacts/grounds need to be clean clean clean!

 

[crispyboy]

When I perform an oil change on my vehicles, I try to hit the ground straps with either Fluid Film or Corrosion X spray hoping it will keep them in reasonable shape.

 

[bigceltic]

So I think the verdict is problem solved. No codes all week! Lesson learned is that those contacts/grounds need to be clean clean clean!

Well, dang it. I cursed myself with my last post! Next day the code came back, and I got it about once a day as I towed my trailer to Zion NP and back (just got home yesterday). Never really affected me at all - each time it was a hesitation, a chime, and a CEL and that was it. It was pretty random, too. I had nothing on the 2.5 hour leg from Green River, UT to (basically) Glenwood Springs, CO, and then twice on the remaining leg. Only once did it stall, when I was idling away from a fuel pump. I guess I missed something somewhere or a wire is loose internally. I am going to have my local shop take a look at it and see if they have any better luck.

 

[brucejohnson]

Well, dang it. I cursed myself with my last post! Next day the code came back, and I got it about once a day as I towed my trailer to Zion NP and back (just got home yesterday). Never really affected me at all - each time it was a hesitation, a chime, and a CEL and that was it. It was pretty random, too. I had nothing on the 2.5 hour leg from Green River, UT to (basically) Glenwood Springs, CO, and then twice on the remaining leg. Only once did it stall, when I was idling away from a fuel pump. I guess I missed something somewhere or a wire is loose internally. I am going to have my local shop take a look at it and see if they have any better luck.

Just curious.
In post #11 Timd32 attached a pdf with some good places to look. I didn't see anywhere in this thread where the ECM connectors were physically checked. Did you disconnect C2 form the ECM and look at/clean/reset the related pins and cavities, including finding/inspecting G114 (ground)? Also, there are two ECM related splices identified in the schematic.
Power: Voltage checks to the power pins.
Continuity: (battery positive terminal disconnected*) Ohm checks from respective C2 pins to B+ (Battery terminals) and respective C2 pins to ground should verify continuity.

• * Never do an ohm check from a power source to ground. Excitement factor elevates. Magic smoke leaks from meter/fuse and/or meter wires.