Looking for ideas....

My truck (2005 ram 2500, 5.9, g56) has been out of commission for the last 3 months due to a g56 failure and very busy mechanic.

I went to start it up today to move it into the shop. Batteries dead; installed a functional battery. Now it cranks but the fuel pump doesn’t come on, the fuel level gauge, and the volts gauge don’t come on. All of the rest of the dash board lights come on, the truck cranks strong but with no fuel it won’t start; obviously. We have checked all of the fuses and they all test good. Also looked at all of the relays and all of them look clean (through the clear windows) any thoughts? Ignition switch? Fuel pump harness?

Still has stock in tank pump that it left Mexico with. Would a failed fca do this? It started fine last month and ran for 60 seconds, then the odometer glitched a little and it shut off and wouldn’t restart. I chocked up to a weak alternator last moth and draining off the little bit charge on the batteries. I haven’t tried to pull codes yet but that will be tomorrow’s mission.

installed a functional battery as in just one? just because you think the engine is turning over fine doesnt mean there is enough reserve energy to keep the ECU happy in the voltage department. id do 2 batteries or 1 good battery and jumped off another diesel at least....

if the cp3 is healthy ive seen several trucks start up with no LP (if there is enough fuel in the tank to create gravity pressure.

the alternator has nothing to do with cranking. if it died after a minute of running and the dash went crazy i would bet money on an electrical issue. dash problems themselves are normally in the 06's but the truck still runs fine because the dash is just receiving signals, not computing them so to speak. someone correct me if im wrong.

do you have a way to log RP while cranking?

after you get known GOOD batteries in there, unplug the FCA and try again

-Marcus

When my ECU went out I had exactly the same problem your describing. Not saying that is your problem, however i would throw two fully charged batteries in there and see what it does. When i had an FCA problem it failed to the max, doubt that is what is causing your issue

Has it sat for three months where the toothy critters could get in it ? They will chew chit just to be mean.

SixOhh said:

installed a functional battery as in just one? just because you think the engine is turning over fine doesnt mean there is enough reserve energy to keep the ECU happy in the voltage department. id do 2 batteries or 1 good battery and jumped off another diesel at least....

if the cp3 is healthy ive seen several trucks start up with no LP (if there is enough fuel in the tank to create gravity pressure.

the alternator has nothing to do with cranking. if it died after a minute of running and the dash went crazy i would bet money on an electrical issue. dash problems themselves are normally in the 06's but the truck still runs fine because the dash is just receiving signals, not computing them so to speak. someone correct me if im wrong.

do you have a way to log RP while cranking?

after you get known GOOD batteries in there, unplug the FCA and try again

-Marcus

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The tank is full so you are right it should start even without the fuel pump, didn’t think of that... Thanks.

Yes I do have a RP gauge I didn’t think about that either. I will report back on that reading.

Snedge said:

Has it sat for three months where the toothy critters could get in it ? They will chew chit just to be mean.

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I don’t believe so; it was sitting in a parking lot with no woods anywhere close. I do want to lift the tipm/fusebox to see the bottom just to confirm nothing is chewed, kinked, or otherwise damaged. First step will be to replace both batteries with new ones. Second will be to try to start with the fca intact, third will be to try with fca disconnected. Fourth; lift the tipm to check for damage or loose wires/connectors. If all that checks out start hunting for an ECM. Any other suggestions?

Tried to connect a code reader to the OBD2 and comes back no connection when trying to pull codes.

I would disconnect TIPM/ECU plugs, clean them and see if that changes anything. Like i said earlier my truck did literally this exact same thing and it was the ECU. That is what i would go with if everything else you plan on trying does not work.

Sounds like ECM time.

Has anyone had good luck with any ECM repair companies? I’m looking at Carcomputerexchange.com right now. $615 seems fair?

natemorrell said:

I would disconnect TIPM/ECU plugs, clean them and see if that changes anything. Like i said earlier my truck did literally this exact same thing and it was the ECU. That is what i would go with if everything else you plan on trying does not work.

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My mech looked at the connections and wires from the bottom and saw no issues. I will look closer at them tonight.

Chowderhead72 said:

Sounds like ECM time.

Has anyone had good luck with any ECM repair companies? I’m looking at Carcomputerexchange.com right now. $615 seems fair?

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This is who i had do mine. I called them, gave them all of the vehicles info and had the ECU two days later. A years later no problems.

Before you load up the parts cannon and let loose on it, you should take apart ALL the battery terminal connections and clean them individually. I have had countless trucks especially the ones that use CAN systems at my shop for issues involving a no start that just turns out to be a corroded wire on the battery

bigstacks95 said:

Before you load up the parts cannon and let loose on it, you should take apart ALL the battery terminal connections and clean them individually. I have had countless trucks especially the ones that use CAN systems at my shop for issues involving a no start that just turns out to be a corroded wire on the battery

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Parts cannon.... You know me too well....

ECM is out of the truck... I have a friend that works at a dodge dealer that will scan the ECM. Stay tuned.

bigstacks95 said:

Before you load up the parts cannon and let loose on it, you should take apart ALL the battery terminal connections and clean them individually. I have had countless trucks especially the ones that use CAN systems at my shop for issues involving a no start that just turns out to be a corroded wire on the battery

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ive seen that before with walmart batteries too :nail:

SixOhh said:

ive seen that before with walmart batteries too :nail:

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Ah yes, the ol' NeverStart's

Brand new Deka 1000amp batteries, cleaned all battery terminals, inspected the ECM connector; no corrosion or discoloration. Pretty sure it’s an ECM.

Power and grounds are good at the ECM? I’ve seen weak batteries pop a fuse under heavy voltage draws... Even seen a few wires fry when folks have used harbor freight “fuses”. (They don’t exactly pop at the advertised amp rating)