Swapable ECM's?

DZL JIM · Mar 4, 2016

Anyone have a list of what ECM codes match up for swapping them out?
I have a truck here (been sitting for a while, but would turn over with key year and half ago when I got it) that we just finished work on and XRT would not load or set back to stock either. IDS won't flash to stock. We tried another ECM but IDS spits it out and says invalid part.
So, I'd like to know if I have to get the same 4 digit code ECM to try, or are there several that are compatible with mine (GSB1)?
I can flash with IDS, just need a good ECM to pop in and see if it's ECM or bad XRT.

Thanks.

tbsimmons · Mar 4, 2016

It doesn't have a tap shift in it does it?

DZL JIM · Mar 4, 2016

Don't believe so. Just an old beat up 2wd XL flatbed. I've had for about 1.5 years, got with toasted motor, not sure how long it sat before I got it.

drunk on diesel · Mar 4, 2016

All 6.4 ECM'S physically interchange and can be programmed with any PN/strategy.

At least that's been my experience.

Did you have the cab off?

DZL JIM · Mar 4, 2016

Yes, had the cab off. Once done with everything we tried to load the XRT (never thought to try and start it first with the typical emish stuff missing), it got to 44% or whatever a few times, sometimes more, even up to 96% once I think, then would stop "Downloading". After hours of messing with it, tried going back to stock and now won't do either. IDS won't let us do anything with it, and IDS won't accept our spare ECM so I figured we needed one of same code. ??

Any help is much appreciated. Thanks.

sootie · Mar 4, 2016

long shot but you checked all harness connections right? and yes, any PCM can be programmed to whatever vin/strategy your truck is. By chance is the PATS padlock blinking on the dash?

drunk on diesel · Mar 5, 2016

Even if PATS isn't programmed, you can still program the PCM. May be a weak/flaky ECM, but it would definitely be a one of very few.

I'd double-check/reseat all bulk head harness connectors from the cab pull.

Make sure battery connections are good and maybe hook another vehicle or a jump box to it when programming.

IDS can't talk to it right now because there's no OS to talk to. The XRT is in recovery mode and will force flash the computer.

Do you have another 6.4 truck on hand?

DZL JIM · Mar 7, 2016

No pats light, I've gone through that once before and made a point to see if that was it.
We're going over all the connection tomorrow.

I know IDS can't talk to it because there's nothing on the ECM, but it doesn't explain why we can't program a new ECM.
I'm not sure what you mean by the XRT force flashing the ecm. It won't do anything for returning back to stock. Is there another way to do it with the XRT?
Yes, we have another 6.4 truck here (mine). What can you suggest?

I appreciate all of the help.

sootie · Mar 7, 2016

if you want a known good ecm lmk. truck should start and run with a good ecm even if it has a mismatched vin code etc. i have one kicking around with an H&S tune on it...

drunk on diesel · Mar 7, 2016

truck won't start with wrong VIN in the PCM because PATS verifies the PATS module against the VIN in the PCM

you can take the ECM/TCM off of the truck in question, put them on the other 6.4 you have, and program them back to stock with the XRT.

DZL JIM · Mar 8, 2016

Yeah, you can't swap ECM's in 6.4's like you can with 7.3 or 6.0.

I follow you with swapping the computers the other way.
Thanks for the tip.

sootie · Mar 8, 2016

drunk on diesel said:
truck won't start with wrong VIN in the PCM because PATS verifies the PATS module against the VIN in the PCM

you can take the ECM/TCM off of the truck in question, put them on the other 6.4 you have, and program them back to stock with the XRT.

my truck was a freak then...

DZL JIM · Mar 8, 2016

I bought 2 6.4 trucks in '14 both with blown motors. They were identical in every way possible, and in fact had sequencial serial numbers. I had ECM issues with one and swapped in the other to trouble shoot and it would not start.
No idea how you got lucky, but don't expect it next time!

drunk on diesel · Mar 8, 2016

sootie said:
my truck was a freak then...

you could get XL's without PATS

I have a non-PATS cluster on hand

DZL JIM · Mar 8, 2016

Ok, Checked all connections, traced everything possible, not sure why but got it reflashed.
Now it will crank with the key but won't build any rail pressure (up to 43 psi at one time). Working on that headache now....