[FIXED] 02 dodge dakota 4.7 automatic Crank no start

hello all...I am currently working on a 2002 Dakota with a crank no start condition. I am leaning towards a PCM but want to get feedback from others first. Here is what I know - After the ignition has been on a few seconds, the odometer flashes then displays No Bus. A scan tool will not communicate with the pcm. I DO have a 5 volt reference. I scoped the cam and crank sensor and both signals look good. I have also found that the PCM is not providing the ground for the ASD relay. At one point, I sprayed starting fluid in the intake and it fired. At that point I decided to check for injector pulse. I found no pulse, and after doing this, it would no longer start with starting fluid. If I provide the ground for the asd relay I do gain power to the coils and injectors. I did not check for injector pulse while activating the ASD but I doubt I had it as it still did not run or fire on starting fluid. I also checked the obvious fuses, and powers and grounds to the PCM. Anything else I should check before selling an expensive PCM? Thanks in advance!

Hey Dan! I totally understand your apprehension about replacing the PCM, but I think that's what you're looking at. Your testing looks solid, and I don't see anything that you've missed. I feel like the starting fluid thing might have been a red herring, as starting fluid is (sometimes) volatile enough to burn on it's own, without spark.

It'd be nice to know if you could communicate with the other modules on the bus (just to make sure the bus isn't dead), but I don't believe that would cause a no start. I'd say double check yours PCM powers and grounds, eyeball the PCM connectors for pin fitment and/or corrosion, then replace that sucker.

For giggles, you can also try getting the PCM in your hands and flexing it back and forth, or wiggling the connectors. If stuff suddenly comes back to life, then you're on the right track.

You said it would be nice to know if I could communicate with other modules on the bus...do you mean if I can just communicate with other modules via scan tool? If so, yes, a scan tool will communicate with other modules. If that's not what you mean please elaborate because I'm not super familiar with network stuff. That is for the reply!

Nah you got it, that answered my question. Let us know ow how it goes if you go ahead with PCM replacement?

Will do. We should have one around Wednesday.

Got the new pcm today. Installed it, turned the key one and heard the pump prime. I knew that was a good sign. Tried to start it and it fired right up and ran perfect. Made me feel good to know I made the right call and didn't waste someone's money!

Not sure where I click to be able to edit my post as [fixed]...I don't see it anywhere

Yeah, sorry about the editing issue, not just you.

But congratulations on the fix! PCM is never an easy call, even with all the evidence you gathered. Any issues with the programming?

Nope, we ordered it pre flashed from the manufacturer. We don't have programming capabilities at our shop. We thought about it but until you get a couple different laptops with outdated versions of Windows, the module to do the programming and the subscriptions to the manufacturers, it's pretty much not worth it. Might be different for a shop that deals with it a lot but we don't and can't justify the cost and time involved.