And problem still exists. The only thing I never checked was the vcm, but it just doesn't make sense why it would suddenly have an issue. I didn't really check step 3 where you monitor the voltage coming to ICM B while cranking because the next step on that was unplugging the VCM, etc. But...
So...update...I'm an idiot. The reason that one pin was dead is because I had disconnected the other end that goes to the coil when I tested it. That's why I couldn't duplicate it. However...
I decided to test the actual ignition coil while I was at it. You're supposed to check the resistance...
Well, given what led up to the issue, I decided to "work backward" and leave the VCM the hell alone unless I had to!! Got a $4 test light from Harbor Freight and checked the ground on connector C on the ICM plug - worked fine. Then I flipped the other side of the probe and put it on ground and...
So of course now I'm a little worried. Lol. In step 4 it says to disconnect the Grey connector from the vcm and then check the wire that goes to the icm. You're saying once I disconnect that, it's going to make it need to relearn etc? Just the process of disconnecting it won't mess anything up...
A little extra help here - apologize if these are dumb questions... Below is the wiring diagram from the P1351 troubleshooting.
Step 6 says to "Check for a faulty VCM connection." (Similarly Step 13 says "Check for a faulty ignition coil module connection.")
What exactly does that mean? Is...
Thanks and glad I'm not alone!!! Gonna be warm tomorrow and I have a bit of a break from work so I'm going to run down those wires. One thing that I'm a bit confused on is exactly what "ICM" stands for. I thought it was "Ignition Control Module", which is a newly installed AC Delco. But the...
Actually, there was no 1345 at the beginning. :) That didn't come until after the 2nd trip to the shop and I never saw it personally. Regardless, here's the update...
I took it back over and told them I wanted to verify my scanner. Lo and behold it read -7 degrees (same as I'm getting). So they...
1345 never came up until after the actual distributor was changed. I only know it came up because he told me it did while he was still working on it. As far as the RPM, the official GM service info is below. The offset doesn't swing that much in general and doesn't vary much. There is nothing...
I'm not sure I know how to tell this. Is this something I should be able to audibly hear or visually see or am I just looking for a bunch of misfires to suddenly show up on the scan tool? Sorry to be thick - I'm not real versed on this stuff as you can tell. :)
All the readings have been done around 1500 give or take a few 100rpm. There's plenty of thermal paste on the icm as well - I watched that myself.
I want to get the timing right first and see what happens. Regardless of whether it has anything to do with the start/1351 issue, it needs to be...
Fwiw, went out to visit my dad today and plugged the reader into his 97 suburban (same as my Tahoe but with half the miles). It read - 0.8 at 1500rpm. So I think the reader is giving me accurate measurements.
Not sure they're related either. Just layers of an onion at this point. I do not ever recall the distributor being out specifically but the I believe the lower intake gaskets were done some time ago (not sure about this either).
I've got a meter. :)
I don't care about blame - I'm trying to figure out if it's even possible that the guy had it set at 0 and by the time I checked it after a short drive it was at -8 (it read -13 when I took it in).
So let's take it from the top...
Rainy day, truck would not start - no spark (verified).
Next...
My basic point was that I made sure I got the rpm over 1000 before checking the number. I know it's supposed to by +/-2 which is why I'm frutsrated. I haven't looked at the hold down yet.
Really getting frustrated on this...Turns out he only replaced the distributor cap and rotor the first time (after which I got the initial 1351 code). So now he finally replaced the whole distributor (showed me where the gears were worn, blah, blah). Said it never had the start up issue (where...
I took it back over and told him we've got to get the cam retard set regardless and to check the connections while he's at it. Gotta peel the onion and the first layer is that offset.
Brand new ignition coil and 2nd new ICM (this one is AC Delco) as well as distributor assembly and spark plug wires. I don't think it's the ICM although there might be a funky connection on one of those components.
That's what I was expecting, that I'd get P1354. Still seems like it should be adjusted properly, I just can't convince myself it's the cause of my original issue, which is the P1351 that GM says is "Ignition Control Module Circuit High Voltage".
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