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Brand new member, I've been reading and working for days trying not to bother anyone.......PLEASE HELP
Something is shutting down ignition. I have no fuel no spark. Ignition switch has good Bat, 2 good Ign and 10v on crank. PCM in plug 1 has good Bat on #20, good Ign on#21 but no Ign on #19. New PCM, New Ign switch, cam sensor, cleaned throttle body. Can anyone help me figure out where to go from here please?
 

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Discussion Starter #2
Brand new member, I've been reading and working for days trying not to bother anyone.......PLEASE HELP
Something is shutting down ignition. I have no fuel no spark. Ignition switch has good Bat, 2 good Ign and 10v on crank. PCM in plug 1 has good Bat on #20, good Ign on#21 but no Ign on #19. New PCM, New Ign switch, cam sensor, cleaned throttle body. Can anyone help me figure out where to go from here please?
edit: car died, new pcm had trouble then ran REALLY WELL then died again. Died like thre plug was pulled out.
 

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2004 chevy trailblazer_lt
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First question - why was the PCM replaced? Second question - who replaced the PCM and was a relearn/reprogramming of the PCM performed so it talks to the other control modules properly?
 

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Discussion Starter #4
First question - why was the PCM replaced? Second question - who replaced the PCM and was a relearn/reprogramming of the PCM performed so it talks to the other control modules properly?
TY, first sorry I forgot it's 4.2. So it died after intermittent run rough and cruise control issues. I was thinking VVT solenoid, I've since put in a nice clean used one. Truck died after running as usual for a few hours and it was like the cord pulled out of the wall. I had not spark no fuel prime. Codes I got were, p0128, p0014, p0016. I got a new cam sensor and nothing. I cleaned and checked ohm of crank sensor and reinstalled. I checked all fuel wires and jumped pump at fuse box and it works. So i was lost and a professional friend came by to donate some time and he was stumped and then by accident with his electric probe tester he touched the pcm and heard the system turn on. The truck started right up. We added a ground wire from the battery to the pcm and it ran for 20 min then stalled and would not start again. I ordered a pcm from Highway 71 Auto Parts programmed and shipped for like $80. I got it and put it in. It did not want to start at first, it did not seem to be the key matching issue as the security light was turning off within 5 seconds or so. I did keep killing my battery trying to get it running so I was using a charger. At one point I left it to charge for while and when I tried again she started and ran great. It idled for 1/2 hr I drove for 1/2 hr then stalled, then started then stalled after cruising around a bit. Then I drove to town and back like an hr or so and was all good. Left me stuck roadside again like the plug was pulled and will not start, same condition. Towed home and Highway 71 was SOOO AMAZING they sent me a second pcm. Still NOTHING. Ive done the key thing with the first new pcm but i think was a waste of time as the security light was not staying on for 10 min. So i did do ignition switch too and the stuff I know about that is above.
Thanks for trying
 

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OK, thanks for the information.

I have to admit that this is way above my experience level, and I'll ask a couple of the pros on here to chime in. I'll send them emails so please be patient.

Message sent!
 

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good Bat on #20, good Ign on#21 but no Ign on #19.
Some clarification is in order here. No power to the PCM at C1,#19?? There should be power to this terminal in both RUN and CRANK key positions. Since you seem to say it has run at sometimes then at those times you must have had power there but not when you tested it?? If true then there is a faulty connection somewhere. C1,#19 power is fed from fuse #36 to the ignition switch terminal B. With key at RUN and CRANK power flows from ign sw term B to term C. From term C power then travels through fuse #28 to PCM C1,#19. This same power from fuse #28 feeds the fuel injectors and ignition coils so loss of this power will drop the engine out dead.

I would thoroughly verify all circuits of the ignition switch. The ignition switch has 2 different power feeds and 5 separate loads that close and open in different key positions. All of these circuits should be verified but in particular the aforementioned terminals B & C.

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Thanks for chiming in TJBaker!!!
 
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