Need some basic help...PCM problem

[mongosd2]

No Start on my engine, was running fine, but then sat for a bit and the batteries go low, normally it would start with voltage as low as 11.3, but this time no go. charged batteries, now no start. I think I fried my PCM...the MVR2 is flashing both the ODB and Host lights in a constant pattern. I can read the pcm thru editor, and while running scanner, show coils but misfires history, throttle position, tps sensor, desired position, accelerator position default, relative, command throttle actualor are all greyed out.

suggestions

[blindsquirrel]

suggestions

https://forum.hptuners.com/showthrea...og-amp-cfg-too

[mongosd2]

https://forum.hptuners.com/showthrea...og-amp-cfg-too

So what do i donwload, from scanner or editor...yes I'm stupid

[blindsquirrel]

The tune file that is currently in the PCM (*.hpt), and a log file (*.hpl) showing it doing the things you're trying to describe with only words.

[mongosd2]

here's both files...

[twenglish1]

Were you cranking the engine while recording that log? Showing zero RPMs, PCM won't do anything without a crank signal

[mongosd2]

Were you cranking the engine while recording that log? Showing zero RPMs, PCM won't do anything without a crank signal

yes...cranking

[twenglish1]

I would start with checking the crank sensor/sensor wiring to start

[mongosd2]

did that...but will check it again
thanks

[twenglish1]

It looks like all the channels you had added to the scanner showed up on the log, do the coolant and intake air temperature sensor readings in the log make sense to what the conditions were when you recorded the log? Map sensor reading didn't change from 1.5psi, O2 bias voltage fluctuates, seems like the PCM is at least partially alive, especially since you have been able to connect to it and read the calibration off it

I went off the 2004 2500 with 6.0 in the data log for the crank sensor wiring:

crank.png

Would also be wise to confirm you have all the 12v and grounds at the PCM

power.png

[mongosd2]

Will look at grounds..map sensor was intermittent before this started happening?thanks

[twenglish1]

MAP sensor wiring:
MAP.png

What did you mean by this your initial post:

misfires history, throttle position, tps sensor, desired position, accelerator position default, relative, command throttle actualor are all greyed out.

If it is what i am thinking it is, it usually happens when you have channels in the list that aren't supported by the currently selected vehicle like below:

Screenshot 2024-12-15 185535.png

Connect to the vehicle first with VCM scanner the little car icon below the menu bar, then add channels, they shouldn't be grayed out then as i believe it only shows supported channels after you are connected to the vehicle

[mongosd2]

MAP sensor wiring:
MAP.png

What did you mean by this your initial post:



If it is what i am thinking it is, it usually happens when you have channels in the list that aren't supported by the currently selected vehicle like below:

Screenshot 2024-12-15 185535.png

Connect to the vehicle first with VCM scanner the little car icon below the menu bar, then add channels, they shouldn't be grayed out then as i believe it only shows supported channels after you are connected to the vehicle

All channels were present/supported before this started happening...

[twenglish1]

Definitely strange, only other thing i can think to check regarding the grayed out channels is the selected vehicle in the menu at the top, although i believe it auto selects it when you click the connect to vehicle button. I would try deleting the current list, connecting to the vehicle and adding them back

[mongosd2]

Definitely strange, only other thing i can think to check regarding the grayed out channels is the selected vehicle in the menu at the top, although i believe it auto selects it when you click the connect to vehicle button. I would try deleting the current list, connecting to the vehicle and adding them back

Copy that...will get back to it tomorrow...

[gtstorey]

There is also a re-poll available parameters.

[edcmat-l1]

You can't really "fry" these PCMs. It looks like that thing has a bunch of wiring issues or a bunch of stuff is unplugged. The PCM doesn't know the engine is cranking.

[mongosd2]

You can't really "fry" these PCMs. It looks like that thing has a bunch of wiring issues or a bunch of stuff is unplugged. The PCM doesn't know the engine is cranking.

copy that...there may have been a crank position relearn done inadvertently and may have started the trip down the rabbit hole with too many cooks in the kitchen. MAP sensor had a bad ground...

[edcmat-l1]

copy that...there may have been a crank position relearn done inadvertently and may have started the trip down the rabbit hole with too many cooks in the kitchen. MAP sensor had a bad ground...

You can't do a crank relearn unless it's running properly. And doing a crank relearn won't fix anything and it won't hurt anything.

[twenglish1]

Learned crank variance is used for misfire detection, don't think it is used by anything else. Did the wiring check out for the crank sensor? Should see 100 or so RPM on the scanner while cranking engine, schematics i posted above would be the direction i would be going with this, good you got the MAP figured out, is it reading correctly now?