P1351 after replacing ignition coil and icm

[doncaruana]

Ran into a start issue when it was really rainy and wet but started again when the next afternoon after it was been dry. Had original distributor, ignition coil, and ignition control module with 290k on my 97 Tahoe. So I had them all replaced as well as spark plug wires (plugs were already new). Now it sort of seems like the first time I try to start it it will start but then immediately stop but after that its fine. But I got this p1351 code now. I even cleared it after the work was done and it came back. The description says it's "ICM circuit high voltage".

Would a bad ICM cause this? I still have no check engine light and I'm just puzzled exactly what this means and what it will do in the long run.

UPDATE: Went out this morning, cleared the code and took it for a 30 minute test drive. Came home turned it off, started it again. No reoccurrence thus far and no issues starting at all. Is this something that could have just been a little wonky the first bit of starts, etc right after all the changes and had to get all in sync?

 

[exp500]

Distributor not correctly set. +- 1degree at1000 rpm. requires scanner. Many cheap bluetooths will do this, name varies with app,Cam Retard Offset is one name . Many posts here.
Reply here if you cannot find it or need help.

 

[doncaruana]

Code came back and exact scenario - start fine, run for about a second and stall. Second attempt to start works fine and runs fine after, not rough or anything.

@exp500 -wouldnt the distributor cause a more consistent issue?

 

[exp500]

P1351 does many strange things. Search this site for more info. It is a MUST FIX.
What are you using for scanner?
What is the repair history? You said coil and ICM replaced. Both Delco? If Dist is properly adjusted and P1351 comes back Dist may be worn. Rockauto United works good.

More Information for UNITED MOTOR PRODUCTS 9362

More Information for UNITED MOTOR PRODUCTS DCR820X

 

[doncaruana]

P1351 does many strange things. Search this site for more info. It is a MUST FIX.
What are you using for scanner?
What is the repair history? You said coil and ICM replaced. Both Delco? If Dist is properly adjusted and P1351 comes back Dist may be worn. Rockauto United works good.

More Information for UNITED MOTOR PRODUCTS 9362

More Information for UNITED MOTOR PRODUCTS DCR820X

I have a regular old OBDII scanner I bought many, many years ago when I was still making payments on the truck. I just had the ignition coil, ICM, spark plug wires, and distributor assembly all replaced at the same time, after which this problem presented. Before that, I had a complete no start, no spark condition when it was really rainy but it started fine the next day. I suspected just the coil but had all of the above done anyway since it was all factory original (except wires). I had an AC Delco coil and ICM but the guy I had working on it put in whatever he got (Autozone I think) before I got him the parts. This guy's pretty good though so I would like to believe he'd adjust the distributor correctly (can't guarantee anything of course!!). I'm incredibly leary of that ICM but I want to be sure before I pull the plug on swapping it because once I put the AC Delco ICM on there, I'm stuck with it. Heavily leaning toward the ICM as I stare at a new one in the AC delco box sitting next to me...

 

[exp500]

You need something to read Cam Retard Offset. If it runs it is close. If you reset and it comes back, then replace ICM.

https://www.amazon.com/BAFX-Products-Wireless-Bluetooth-Diagnostic/dp/B005NLQAHS

BAFX Products® - Wireless Bluetooth OBD2 Reader / Scanner for Android Devices

The best bluetoothe OBDII reader for Android devices on the market today! Guaranteed to work on ALL OBDII compliant vehicles! Not just a few! Backed by 2 Year warranty from BAFX Products®

bafxpro.com

 

[doncaruana]

@exp500 i got it, bought the gm pid. I'm dumb cause I can't find anything that shows me cam retard or anything like it. Can you (or anyone?) tell me where to find it/set it up in dash command?

 

[doncaruana]

Ok I Found it. So it says -13.4 (at 1000rpm). What should it say?

 

[Fless]

Distributor not correctly set. +- 1degree at1000 rpm. requires scanner. Many cheap bluetooths will do this, name varies with app,Cam Retard Offset is one name . Many posts here.
Reply here if you cannot find it or need help.

Ok I Found it. So it says -13.4 (at 1000rpm). What should it say?

+/- 1° at 1K rpm.

 

[exp500]

Dist cap/rotor, ICM, Coil, plug wires are known failure points on these trucks. Put it on shelf, you will need it and it's 20 years old so good parts harder to get. You should be good for 20-40k miles now.

 

[doncaruana]

I talked to the guy who just replaced the distributor and mentioned all this and he said there is no adjustment for it. And then I find this. The 5.7L engine is what came in this truck, so I think this may actually apply? I honestly don't even know how to tell, but I think this is what I have. Can anyone tell me how to verify?

 

[YukonGTmaster]

Are you sure you are reading CMP Offset? I made a mistake using DashCommand where I was actually reading “Timing” with numbers close to yours. I finally got the GM PID loaded and I had to rotate my distributor counter clockwise until it was contacting my upper intake, and I was able to dial it in to -.3’ at 1000rpm.

 

[doncaruana]

Are you sure you are reading CMP Offset? I made a mistake using DashCommand where I was actually reading “Timing” with numbers close to yours. I finally got the GM PID loaded and I had to rotate my distributor counter clockwise until it was contacting my upper intake, and I was able to dial it in to -.3’ at 1000rpm.

This is what I got

 

[YukonGTmaster]

I talked to the guy who just replaced the distributor and mentioned all this and he said there is no adjustment for it. And then I find this. The 5.7L engine is what came in this truck, so I think this may actually apply? I honestly don't even know how to tell, but I think this is what I have. Can anyone tell me how to verify?

View attachment 364513

You can verify, by disconnecting your battery. Pulling #1 spark plug out. Pulling your distributor cap off and out of the way. Getting a socket and a large ratchet, and rotate your engine harmonic balancer until the timing notch aligns Top Dead Center on the compression stroke, your distributor finger should be aligned to the triangle like picture. Then you need to fine tune adjust distributor with truck running, by leaving your distributor hold down bolt just loose enough, you can carefully rotate distributor in fine increments.

 

[YukonGTmaster]

This is what I got
View attachment 364523

Ok you are off by quite a bit.

 

[doncaruana]

What's weird is that it doesn't run rough at all though, nor any issues with power at any speed, sputtering, etc. The only issue is the P1351 code with goes along wiuth a start, stall after a second, then start again and it runs fine.

Plus the mechanic said there is no adjustment for this distributor, just like in the screenshot above (which is actually from Mitchell OnDemand) where it says the distributor is installed in a fixed, nonadjustable position for HVS (which I may or may not have??). So, of course, I'm utterly confused...

 

[YukonGTmaster]

What's weird is that it doesn't run rough at all though, nor any issues with power at any speed, sputtering, etc. The only issue is the P1351 code with goes along wiuth a start, stall after a second, then start again and it runs fine.

Plus the mechanic said there is no adjustment for this distributor, just like in the screenshot above (which is actually from Mitchell OnDemand) where it says the distributor is installed in a fixed, nonadjustable position for HVS (which I may or may not have??). So, of course, I'm utterly confused...

The code you would be latching would be a P1354 code if the distributor was out that much anyway. Hopefully someone else weighs in with some more insight.

 

[doncaruana]

The code you would be latching would be a P1354 code if the distributor was out that much anyway. Hopefully someone else weighs in with some more insight.

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".

 

[Fless]

Sounds like it's time to diagnose that ICM and/or circuit.

 

[YukonGTmaster]

If you have the original iCM still, maybe try swapping it back, clear the code, and see if it latches the P1351 again?