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HELP!!!! 2000 Dodge SC/LB No Start, No Prime, New Lift Pump

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Year of truck: 2000

Motor: 5.9 Cummins

Mods: None...

However, I just had the AC guy evacuate and refill the AC to his spec. 

How is the truck primarily used: Just used to go to work, however, i recently purchased the truck from a guy that wasnʻt using it much. Seems like it was sitting for quite sometime. 

When did the issue start, and if it's intermittent or all the time: The truck turned off last week thursday, and restarted easily. On friday(7/22) i parked it on a hill(running) and it died. I rolled it down and on the side of my house and now it wonʻt start. It throws a P0123 and P1639 code and wont start for sh!t. I can hear the Lift Pump priming, and hit the schrader valve on the IP to see what the pressure looks like -it kinda trickles out. Havenʻt yet checked fuel pressure, but will do it asap. Also, I tried to reset the APPS because thats what iʻve been told the P0123 code is, but nothing. No start, lots of crank. While I tried to start, I cracked the lines at 1 and 3 and no fuel is coming out of there...

Darn truck sent no warning signs or hiccups. Has been running strong until it went Kaput!



So, today, I checked the truck out, cycled the key, and the lift pump cycled. Replaced the lift pump, and now... NO CYCLE! When I was replacing the lift pump, I noticed the fuel line was rather dry. The in and out lines both leaked no fuel which is rather odd, given the last time I replaced a lift pump, I lost some fuel. I am dumbfounded that the cycling is not happening...


Thank you all in advance for your help...





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I merged your two posts.  



Couple of questions.  What did you replace the lift pump with?  another block mounted?  Did you verify that you are getting 12v signal from the ecm plug to the lift pump?  


the lift pump really needs to be put on a relay vs power directly from the ecm.   



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How are you checking for trouble codes? I would almost bet there is more in there. You could hot wire the new lift pump to see if it works or as mentioned above see if you have voltage going to it from the ECM

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Ok so, I did replace the pump with another block mounted pump, and Iʻm assuming i wasnʻt getting 12v to the lift pump, because THIS MORNING, I went down to my truck, turned the key and the pump was priming. Although it was priming, it still did not start. I did not check if there was fuel at the IP, but im gonna try and drain the filter and housing and change filter... 


I have been checking the codes through the dash, iʻm certain theres more... Is it possible that my ECM is fried?



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Scan for codes using a code scanner and report back.  Don't jump to conclusions yet about anything being fried.  


Also check your electrical system for AC noise from a bad alternator, that can cause all sorts of strange issues.

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The ground that goes behind the alternator to the gray clip was relocated to the front, heard it was doing the jumping TC thing, since i've had it, nothing went wrong until this... so Iʻm assuming AC noise was a struggle. I'll check on the codes, how do you check for AC noise?

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Ok, so, I changed the Fuel Filter, lift pump, and bled the system. IT RUNS NOW... could it possibly have been a plugged filter in combination with a bad lift pump? 


There are still codes, however I havenʻt had the right scanner to pull it from the truck. On the ODO it will only pull P0123 & P01639.... But starts and RUNS FINE for now...

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-Tried to check for AC noise, but apparently I do not have the correct DVM to do so. Both batteries are steady 12.7 12.8 cold, and get in the 14ʻs, whilst truck is running. Now down to the nitty gritty. Pulled codes and a **** load came up...


Key trick produces:

P1693-Companion DTC from ECM and PCM

P0123-High Input at TPS

Scanner pulled these:

P1689-No Communication between ECM and IP

P0122-Low input at the TPS

P1698-CCD from TCM

P0122(AGAIN)- Low input at the TPS


Damnnnnnn!!!! Where do I start?

Should I ERASE the codes and try to drive the truck?

This is the first time I have done something to this extent... Im pretty versed in mechanics, however, this electric stuff blows my mind. Thanks guys!

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Get a big tube of dielectric grease


Pop the hood,


Unplug every plug under the hood one by one and grease with the dielectric grease.  Ensure you really get the grease in there good, cycle the plug a few times to get it covered.  


Clean EVERY ground under the hood, 


Clear codes, go for a short drive and then rescan for codes.  



I would HIGHLY suggest getting a good multimeter,  that is the single most helpful tool in a toolbox.  

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