Ficm electrical issue any input - Competition Diesel.Com

slor1de · 01-28-2020, 06:02 PM

Have an 05 lly cab chassis zf6 truck. Blew the edu fuse. Had wires rubbed thru on driverside connector at valve cover, harness smelled of burnt wires. Replace harness with new GM engine harness. Truck is not blowing edu fuse after harness install and will start and run. Throwing u0105 and u0073, have power and ground at ficm connector. Truck doesnt seem to be firing on #3,5,8 cylinders, Makes no difference when killing injectors with scanner on 3,5,8. Builds and carries desired rail pressue, balance on 3,5,8 is higher that the rest.

Anyone have any input. Feel this is 100% electrical. Like to try a ficm, but sounds like there failure is rare. (Any way to test the ficm). This truck was running fine all day, shut off for lunch, this happend when attempting to start afterward. 250k mile truck bone stock with 30k mile on a jasper long block and 8-10k mile on complete new fuel system from sending unit,filterhead,cp3, and injectors.

Mark Nixon · 01-29-2020, 09:09 AM

Bump it up.
Can anyone help this fellow out?

Mark.

JWhite · 01-29-2020, 02:19 PM

You'll have much better luck with the guys on DuramaxDiesels.com

The FICM is rare to have problems, but it happens. IIRC, when it sees a short or loss of connection to one injector the whole bank will shut down. Maybe double check your injector plugs, and look into the icepick fix.

But based on what happened, I'd say the harness shorted out and toasted the FICM. If the harness is new, and connections are good, there's no reason for it to throw those communication codes.

slor1de · 01-29-2020, 04:55 PM

Jwhite
Harness is new GM. Have been over the connections a few times, will check again . I agree the ficm failure is rare. I feel the shorted harness got the ficm.

Mudn_1 · 01-29-2020, 05:36 PM

So Cyl 2 does fine? 2,3,5,8 are bank 2. but typically if one goes down or has a poor connection it will shut the bank off if its an electrical issue between the ficm and injector.

slor1de · 01-30-2020, 04:51 PM

Mudn
Yes, its just 3,5,8
I think a got another ficm lined up to try begining of the week. Hopefully that will fix or rule out the ficm

slor1de · 02-04-2020, 07:09 AM

Tried a known good ficm of another truck. Runs fine now, no codes.

01-28-2020, 06:02 PM	#1
slor1de Name: slor1de Title: Too Much Time Status: Not Here Join Date: Feb 2007 Location: Kittanning, Pa Member`s Gallery Posts: 907	Ficm electrical issue any input Have an 05 lly cab chassis zf6 truck. Blew the edu fuse. Had wires rubbed thru on driverside connector at valve cover, harness smelled of burnt wires. Replace harness with new GM engine harness. Truck is not blowing edu fuse after harness install and will start and run. Throwing u0105 and u0073, have power and ground at ficm connector. Truck doesnt seem to be firing on #3,5,8 cylinders, Makes no difference when killing injectors with scanner on 3,5,8. Builds and carries desired rail pressue, balance on 3,5,8 is higher that the rest. Anyone have any input. Feel this is 100% electrical. Like to try a ficm, but sounds like there failure is rare. (Any way to test the ficm). This truck was running fine all day, shut off for lunch, this happend when attempting to start afterward. 250k mile truck bone stock with 30k mile on a jasper long block and 8-10k mile on complete new fuel system from sending unit,filterhead,cp3, and injectors.

01-29-2020, 09:09 AM	#2
Mark Nixon Name: Mark Nixon Title: No Savior among the flesh Status: Not Here Join Date: Feb 2009 Location: Brownville, Nebraska Member`s Gallery Posts: 8,676	Bump it up. Can anyone help this fellow out? Mark. __________________ If you or I did business like the PEOPLE in government do business, we'd be put in jail. Government is coercive. Anarchy: The state of existence where there are no masters & no slaves. Therefore, Anarchy means the ABSENCE OF SLAVERY, or, in other words, FREEDOM.

01-29-2020, 05:36 PM	#5
Mudn_1 Name: Mudn_1 Title: Sweet Home Status: Not Here Join Date: Apr 2007 Location: Trussville Member`s Gallery Posts: 5,290	So Cyl 2 does fine? 2,3,5,8 are bank 2. but typically if one goes down or has a poor connection it will shut the bank off if its an electrical issue between the ficm and injector. __________________ "One Up'N The Competition" https://www.facebook.com/pages/Diese...73404032829197

01-29-2020, 02:19 PM	#3
JWhite Name: JWhite Title: Trained monkey Status: Not Here Join Date: Aug 2009 Location: F Burg Ohio Member`s Gallery Posts: 1,817	You'll have much better luck with the guys on DuramaxDiesels.com The FICM is rare to have problems, but it happens. IIRC, when it sees a short or loss of connection to one injector the whole bank will shut down. Maybe double check your injector plugs, and look into the icepick fix. But based on what happened, I'd say the harness shorted out and toasted the FICM. If the harness is new, and connections are good, there's no reason for it to throw those communication codes. __________________ GMC with a LiLLY

01-29-2020, 04:55 PM	#4
slor1de Name: slor1de Title: Too Much Time Status: Not Here Join Date: Feb 2007 Location: Kittanning, Pa Member`s Gallery Posts: 907	Jwhite Harness is new GM. Have been over the connections a few times, will check again . I agree the ficm failure is rare. I feel the shorted harness got the ficm.

01-30-2020, 04:51 PM	#6
slor1de Name: slor1de Title: Too Much Time Status: Not Here Join Date: Feb 2007 Location: Kittanning, Pa Member`s Gallery Posts: 907	Mudn Yes, its just 3,5,8 I think a got another ficm lined up to try begining of the week. Hopefully that will fix or rule out the ficm

02-04-2020, 07:09 AM	#7
slor1de Name: slor1de Title: Too Much Time Status: Not Here Join Date: Feb 2007 Location: Kittanning, Pa Member`s Gallery Posts: 907	Tried a known good ficm of another truck. Runs fine now, no codes.