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Girlfriend's brother replaced timing belt on her truck afterwards P0301, P0304, and a throttle body code that he can't remember. He started throwing parts at it. New plugs, wires, coils, and a junk yard throttle body. That's what I know about prior to me working on it. I have 3 codes that show after every delete P0301, P0304, & P0033 with P2195 only once. I have no signal from ECU IGT1 to igniter. Borrowed an ignitor
& ECU but still no signal on IGT1. IGT2 & IGT3 pulsing at 3.9v Igniter has good ground, 12v, 5v. Continuity good between ignitor and coils also between ignitor and ECU. I've also made sure these wires are good under load. Injectors cleaned and firing but not replaced, 12v to all coils w/good grounds, 5v reference good on all sensors that I've checked. Compression good on all cylinders. Vacuum low, needle on gauge keeps slowly moving between 9-11 inhg. My question is this, what's happened to IGT1? Thank you in advance I truly appreciate any help.
Thanks for jumping in and helping me solve this mystery, this is really a strange case of chasing my tail. The timing was the first thing the brother checked and rechecked. When I took over the job as well and rechecked a couple times also. I've found top dead center more than once in disbelief hoping I missed something but each time all the markings line right up like they should. Please correct me if I'm wrong but if the timing was off would that create a zero signal on IGT1 from the ECU? That fact is what has me confused. I'm left wondering whether or not I've already corrected the problem and it's come down to a "relearn" situation for the computer. Maybe I need to drive it to give the ECU a chance to figure it out?? Thank you for thinking this through with me, please keep the ideas coming. They're much appreciated. HELP?
Here are some better quality images. Only 3 coils on cylinders #1, #3, & #5, Each coil has a secondary wire for the other three plugs. That's why i have P0301 and P0304 because cylinders #1 & #4 share the same coil.
If ya had a scope I’d clear the codes and scope the #1 coil and see if ya get a pulse if the computer is intentionally shutting it down. For some odd reason
This is what i've found so far. There's a lot of info, well worth the investment in Mitchell but I'll keep looking. I appreciate it once again. You've given me new Ideas and direction.
The PCM harness portion that controls the IGT1 is a little suspect to me. When I first installed second PCM I had voltage on IGT1. (I'm fairly positive but this can make anyone second guess) Partly assuming that voltage was there and was shut down by PCM. Keeping it in the back of my mind on the look out for info if it's possible to correct/fix harness without replacing it. Could end up with more issues replacing, so trying to avoid that but prepared to do so.
By chance you did check igt 1 for short to ground right? I know ya tested continuity from pcm to igniter then coil you igniter. Unhook pcm hook ohm meter negative lead to battery negative then probe igt circuits should be infinite resistance
Huh, no I didn't. I'm unplugging the harness from the back of PCM and checking for continuity between IGT1 pin and BattNeg? I did power probe it and it came back as negative polarity but didn't do continuity.
what are your thoughts about the possibility of whatever the issue was, that It might be fix but the PCM needs to "relearn" by drive it a short distance?
I never seen a relearn like that. But anything is possible. Try it if you want. You had pcm and igniter unplugged and power probe showed ground?? If so that’s a problem
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