[Drago]

My 99 dakota with a 5.2 stays running normally after turning the key off and removing it. It's definetly an electrical issue. I've replaced the ignition switch did not fix it. Today I pulled the fuel pump relay and it still continued to run just idled up and down. I ended up pulling the ignition coil boot and would rather not have to do that again lol. Anyone have any other ideas I may be over looking?

Also incase they may be linked and likely are. Other electrical issues with my truck are, gas gauge does not work I've replaced fuel pump assembly with fuel level sender. There's a short in my console/purge slot interior fuse box. Will blow any fuse but a 30a should be a 10a, which is turn causes doors to repeatedly lock while driving, it also would also mess with the anti theft system untill I took an ecu and ctm from my totaled 5.9 that did not have anti theft and put them both in the 5.2 as to not have to worry about the system stopping my truck from running.

 

[immattj]

That is interesting, Drago. I take it you felt the sensation of electricity when you pulled the coil boot. Might have been healthier to disconnect the battery negative terminal?

My understanding, is that when you turn the key to 'ON' the PCM energizes the fuel pump relay and the PCM energizes the ASD relay which allows battery voltage to the injectors and the ignition coil, and then when cranking and running and getting a signal from the crank & cam position sensors the PCM is sending a trigger signal to the coil.

It almost seems like (maybe) your PCM is either not getting the message that you turned the key off or that something internally in the PCM has caused a situation where, so to speak, the right hand is not talking to the left hand.

When you turn the key off, besides the engine continuing to run, do all your gauges indicate that you turned the key off? Or do they continue to show the trucks condition as it runs?

I recently learned that pre-2001 Dodge used the CTM (Chrysler Collision Bus) System which was replaced in '01 by the PCI Bus system. I wonder if you are experiencing a failure of certain modules on the CTM Bus (including your instrument cluster) to communicate with each other or the PCM?

 

[immattj]

. . . so anyway, not that this is offered as a solution, but I would think that pulling the ASD relay should shut your engine off.

 

[immattj]

[. . .] I took an ecu and ctm from my totaled 5.9 that did not have anti theft and put them both in the 5.2 as to not have to worry about the system stopping my truck from running.

I wonder if this is the issue? Now, instead of stopping your Dak from running, one of those units is preventing it from shutting off?

 

[immattj]

. . . as far as your inop fuel gauge, though mine is a '03, in my "library" I do have a Haynes for '97 to '99 and looking at the schematic for '98 & '99, it shows the "fuel level sensor signal" at the PCM at a connection or a point labeled "26" and also as "C3." I never really learned all the ins & outs of reading schematics, but I believe that "C3" would refer to which one of the PCM connectors, or which section of the PCM, the connection is made at. "26" might be the number of the pin on the connector? The wire itself appears to be numbered G4 over 18 and the color is DB which I think is Dark Green and there appears to be an inline connector at C352.

I wouldn't think the fuel gauge issue is necessarily tied in with the failure to shut off issue, but if I were trying to track down the fuel indicating issue, I'd try to trace out that wire.

 

[immattj]

. . . so if the engine is running, it is a given that the ASD relay has to be energized (open) to allow voltage through to the injectors and the coil. Continuing to look at the schematics from '97 to '99, at the C3 plug or section of the PCM are the "ASD relay control" (designated as "3") AND the "ASD relay output" (which is designated as "12"). (The "Ignition Coil Driver" is shown outputting from the C1 section or plug from a pin or wire designated as "7.")

Since the engine needs output from all 3 to start and run and then continue to run, I guess the question is why is the PCM still providing output at these locations when the key is turned off. If the wiring is correct at the ignition switch and nothing is shorting at the contacts there, I would think the issue must be happening within the PCM.

 

[Drago]

Yeah I didn't have a 10mm on me for the battery so it was kind of a how bad could it be moment lol

All gauges operate normally when it happens. Only thing out of place is the airbag light sometimes dings on.


Alright so it seems like my best solution is tracking down and fixing the wiring issue that keeps blowing fuses in the console/purge slot that is causing other issues and put the original ecu and ctm back in to fix the miscommunication. So time to start tracking wires. Thank you for the input man ill report back when I get the time to work on it.

 

[immattj]

Yes, that is certainly interesting.
So after you shut the engine off the hard way by pulling the coil wire, does the rest of the truck now act like the key is in the 'OFF' position & removed? By that, I mean is there nothing now happening on the cluster after you kill the engine in that manner?

I am not at all sure about that console/purge 10a fuse slot. With the fuse removed, that eliminates the short, so what does running with the fuse removed make your Dakota do or not do?

It might come down to you maybe needing to get that 5.9 PCM flashed for your VIN.

If you do get to experimenting & find yourself in a situation where you need an alternate way to shut it off, try pulling the ASD relay--that should result in the injectors and ignition coil losing voltage.