I’ve been having an issue with my truck for a while now and I feel like I’m chasing a ghost but I’m getting more clues as time goes by.

Truck: 2000 Dodge Dakota quad cab with about 116k miles on the body and about 15k miles on the engine. 4.7 V8

Issue: Truck will randomly stop running while driving or sitting at a stop light. The power is still on (lights/radio working) but the fuel gauge shows empty and the fuel pump stops pumping. I’m able to crank it over, but it will not start. After it has a while to rest/cool down, it starts up fine like nothing has happened. This can sometimes be 2 minutes or 20 minutes. One other quirk to this is that it will also clear a check engine light if there was a code being thrown.

I’ve brought it into the shop a few times now and they have been unable to replicate the problem as it happens randomly and then solves itself without ever throwing a code. First time that they had the truck, there was no issue that they could find but the relay was very hot so I thought at first the relay was going bad. Replaced the relay and everything was fine until it happened again. Brought it back in and it was the same story again that they were unable to replicate the issue, but this time they were able to confirm that the fuel pump may be going bad since it was cracked and leaking so I had the fuel pump replaced and fingers crossed. Well, it’s done it again and I’m stumped.

I think that the 2 big clues here are the fact that it seems all electrical connection to the fuel pump is cutting out because it not just that the pump doesn’t work but that the gauge goes out too; and the fact that it will clear any check engine light if there was a code showing previously. I’ve tried to see where the fault lies by messing around with the accessible components to see what will cut out the fuel pump and the gauge; the fuel pump relay will stop the pump but the gauge still works but if I take out the fuse for the relays both the fuel pump and gauge go out. I was hoping that there was some connection issue in the fuse even though it looks good so I switched it out, but it happened again. I noticed that the temp gauge will not show a temperature when the fuse gets pulled so I need to check next time it happens to see if the temp gauge stops working too or if it’s just the fuel gauge. The only things I can think of at this point are that it may be a grounding issue, it could be a connection issue on the fuse panel itself where it might be cracked and disconnects when it’s hot (checking the temp and fuel gauge next time it happens should help determine if it’s something with the fuse) or if possibly a PCM issue.

So here I am coming hat in hand to ask for any advice from someone who has seen this before. I’d like to see if there is an easy way to test out the ground or possibly just add in an additional ground for the fuel pump wires to be sure it’s not that (I need to find the location of that specific ground); I’d like to see if there is a better way to test out the fuse panel (hopefully I don’t have to wait until it happens again); or if there is any way to check out the PCM without just replacing it.

Side note: This is a weird year combination for the fuse panels. It seems that the under hood fuse box is for 2000-2004 but the passenger compartment fuse panel is 1997-2000.

Any help on this would be greatly appreciated. I love this truck even though it’s my secondary vehicle and I don’t want to have to get rid of it for what seems like a simple fix if I can find it, but it’s no use to me if it’s unreliable.

 

Need to know if the other gauges stop working as well. All of them are driven via the PCM thru the communications bus. When it dies, does the Service Engine lite come on? Or do all the lights in the dash go out as well?

 

Just wanted to report back on this one. Turns out it was in fact the PCM. Got a new one ordered from a refurb place and it looked different so I was a little weary. It was thinner and sleeker, not the original metal box with fins that I'd come to know and love. But it worked fine. Had some other issues after the fact that I thought were an issue with the PCM, but they were unrelated. Possible that the new PCM kicked those problems off, but they were actually separate. The Dak is now back on the road and better than ever, while at least better than it has been in about a year of tracking this problem down. Just wish I would have found this out earlier and saved my self the fuel pump replacement. Still not too bad since it was cracked anyway and it was leaking gas back down the fuel line when parked.

 

FOR OTHERS INFO.....
I too ( a few years ago), have gone thru multiple PCM's.
However my orig issue was the dash voltmeter. it would register correctly, upon start up,
and after a few minutes would would peg the needle( showing approx 19 volts.)
I said NO WAY !! you can't get 19 volts from a 12 volt battery. A volt meter showed the correct 12V, when measured at the fuse boxes first PCM fixed that, but had other issues.
2nd unit fixed different issues. bottom line--- I put the orig PCM back, As it only had the one issue, disregarded what the dash reported, and used an aftermarket

( similar to stock photo )
digital voltmeter less than $2.00.
I mounted it atop left side of dash eyebrow, in a small housing.
I wired it to the hot side/& gnd of the fusebox . No problem ever since, with the added distinction of knowing Exactly what the voltage is to the decimal........ with the key on, or off!
It shows 13.4 volts when charging. Now ,I know what's what, at all times.

 

Glad you got it fixed. The fuel pump sits inside the fuel tank, so what was cracked, a hose? Usually they'd want to hook up a fuel pressure gauge to check if was losing pressure. Anyway, its water under the bridge now.