2005 Chevy Truck no start dead pcm?

[Moparjim]

Anyone seen this before, its a 05 chevy v6 and it just cranks no fire. Wierd thing is when I plug in my obdii scan tool it doesnt seem to even power it up, the three emissions readiness leds just occasionally blink faintly..

Is this possibly a dead pcm, or is there some fuses maybe or something?

[LIL EVO]

05 what? It could be that. We've seen cluster issues that wouldnt allow the truck to start too. To rule that out, just unplug the cluster. If it's bad, the truck will start.

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[brotherbenn83]

Does it have fuel pressure? Those 4.3L wont run much below 55psi. Does it have spark? If that still has a distributor(some later 4.3L don't) pull the cap off and check for corrosion on the cap and rotor. PCMs rarely fail on those body style trucks, and I'm not sure what lil evo is talking about, but in 12 years at chevy dealers, I have never seen a internal cluster issue cause a no start...sdms and vcims, sure.

[spooln30]

Definitely check the efi fuse and others and also the relays. In most cases when you can't get into the ECU to read codes it usually means blown fuse, bad wiring or bad ECU.

[Moparjim]

So. Found a blown fusw foe the cigarette lighter that apparently also powers the obdii port. Now I can connwct but no codes, and the live data values for sensors etc sewm believable. However it still doesnt run basically. Now it will start right up, run fine a few seconds, then sputter and die. Will restart like that over and over. I have been able to keep it running by rapidly "feathering" jiggling the gas pedal. If left to idle, or if jeld at any sort of throttle position it just sputters and dies. It will also run perfectly fine sounding if I slowly dribble gas down the throttle body. So, seems to me its starving for fuel bur pump must be coming on or I wouldnt think it would run at all.

[BAD LS1]

Unplug maf and try again. Seen that scenario many times where they cow shit but aren't out of range to physically set codes. Unplugging it will put it in speed density, all though removing iat function at same time.

[lilws6]

At least with the maf off tho it will run if thats the problem i just had this problem on a g6 no start intermittently. Intake air temp is part of the maf and was reading -40* solid. but it did set a code. I'de still unplug the maf and see if it runs. Then if it doesn't i'd be checking fuel pressure

[Moparjim]

Yeah i had already tried unplugging the MAF no difference, but then it did throw a code for it. Will check fuel pressure, I didnt have my gauge with me but pushing in the port by hand gas came out but pretty lazily it did seem like low pressure.

Do fuel pumps fail in a works but low pressure kind of way? My experience is either pump works or dies totally usually...

[Moparjim]

The cap and rotor was gross and we replaced it... I was familiar with that particular 4.3L issue, I used to have to replace the one on my S10 like annually lol.

[lilws6]

ive seen fuel pumps "weaken" before "failing" its rare usually they just die

[Irish]

ive seen fuel pumps "weaken" before "failing" its rare usually they just die

I've witnessed shitty fuel filters that give the symptoms of a failing fuel pump.