ASD / Fuel Pump Electrical Problem

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Nov 23, 2020 | 08:26 PM
  #1  
Hey fellow Dakota owners, I am looking for some help with my 2002, 4.7, 5 speed regular cab Dakota. A couple of weeks ago driving home in the middle of the night on the highway the truck just cut off. Everything stayed on but the motor died. Got it towed home after about an hour of trying to get it to restart on a sketchy curve on the side of the highway. Once home i started probing around and checking for different things. I did not have the 5V reference and my asd relay was not clicking on, and I had a no bus on the gauge cluster. After getting my PCM checked out they told me it was bad and sold me a remanufactured one. Put it on and got the 5V reference, asd relay would buzz still would get no bus. Changed engine 1 and engine 2 fuses under the hood and the no bus went away, truck would crank no start. Fuel pump wasn't turning on. Dropped the tank and the fuel pump was bad (wouldn't start with direct power applied to it). I think it shorted to ground and this is what caused all of my problems. Bought a new one and put it on. This is where i am at. The truck will not receive the ground on the white connector from the PCM to Pin 3, ( AUTO SHUT DOWN RELAY CONTROL) and pin 19 (FUEL PUMP RELAY CONTROL). If i turn the key on no ground from the PCM to these two relay connectors. If i take out the relays and plug them back in the fuel pump immediately starts buzzing, the asd relay clicks and the truck starts and runs normally. I have checked the wiring under the fuse box, i have checked the wiring from the pcm connector to where the relays plug in. They are all good. I back probed the PCM pins 3 and 19 and checked with a multimeter there. The grounds did not turn on until I took out and put back in relays one by one. I called the PCM place and they told me that what I am describing is not possible in terms of the PCM causing this. However i do not know what else to check. Truck will turn on like clockwork if I turn the key to on, disconnect, and reconnect both the fuel pump and asd relays. Is there something in the system that can cause this sort of behavior?
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Nov 24, 2020 | 11:53 PM
  #2  
Just for grins, I wonder if the relays are bad? Fuel pump relay could have got welded internally, not sure about ASD tho
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Nov 25, 2020 | 08:24 AM
  #3  
Quote: Dropped the tank and the fuel pump was bad (wouldn't start with direct power applied to it). I think it shorted to ground and this is what caused all of my problems.
Quote: I called the PCM place and they told me that what I am describing is not possible in terms of the PCM causing this.
Well, since the problem wasn't the PCM in the first place, I'd be trying to return the new PCM and get back my old one.


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Sep 30, 2023 | 12:04 PM
  #4  
Was this ever resolved? I know it is an old post now, but I am having a similar issue. Removing the relays and then putting them back in seems to allow me to start.
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