ground issue. G108 & G109

mmvic

mmvic

New member
These 2 grounds which are located on the drivers side intake next to the alternator are making me think. I've been driving the truck the past year now with these two grounds disconnected unknowingly and recently discovered then warped up tucked away. So i grounded them back to where they go and drove the truck, seemed to run the same.
A couple days later I went to start it and the check engine light came on with 5!! codes, and tons of data errors on datamaster

CODE 13 OXYGEN (02 ) SENSOR CIRCUIT (OPEN CIRCUIT) replaced o2 sensor, bad b/c of race gas
CODE 14 COOLANT TEMPERATURE SENSOR (CTS) CIRCUIT (HIGH) replaced sensor
TEMPERATURE INDICATED)
CODE 31 (code 1 of 2) TURBO WASTEGATE OVERBOOST dont think this applies b/c i am not using factory boost control
CODE 43 ELECTRONIC SPARK CONTROL knock?? i dont get any spark retard on DM
CODE 44 OXYGEN (0,) SENSOR CIRCUIT (LEAN EXHAUST INDICATED)replaced o2

After all that I started the truck and saw fewer codes only 31 and 43. Decided to disconnect the grounds and see.. No codes.Truck seems to run great, i can upload a DM file, maybe someone can see something Im missing.

BTW the grounds are
G108 Cir #551 Tan/wht ECM term D1, ground. LH front of engine. Fwd intake bolt.
G109 Cir #150 Blk. Main ground for Inst Panel harness. LH front of engine. Fwd Intake bolt.
thanks to davep in the Vult
 
sly dvl

sly dvl

Ya, it's got a Turbo
Re: ground issue. G108 & G109

Sounds to me like the phantom codes you get when an ECM starts to fail. Don't see the connection between the codes and the fixed grounds though.
 
Big Mike

Big Mike

New member
Re: ground issue. G108 & G109

Battery volts seem low. Going by the histogram you are running lean all over.
 
mmvic

mmvic

New member
Re: ground issue. G108 & G109

scratch that dm file, that was with low bat.. Thinking this is a bad ecm, I hooked up the grounds again and every time i run the truck a different code pops up. gonna get a new ecm and see what it does.
The thing that's weird is i only get the data errors and engine codes with the grounds grounded
 
mmvic

mmvic

New member
Re: ground issue. G108 & G109

Stupid thread, discard everything I said. I am just going to run iit w/o the grounds connected.
 
WyoSyclone

WyoSyclone

Active member
Re: ground issue. G108 & G109

It almost sounds like the G100 ground (rear of right side head) may be missing, thus the engine is running at a higher potential due to the alternator running at 14volts as opposed to battery's 12. When you hook up 108 and 109 the higher potential of the running engine is back feeding through the ECM. The higher potential is going through the ECM and cab grounds, then getting back to the battery via the 101 ground on the right side radiator support by the battery...... at least that's what my puny brain has pieced together ;)
 
mmvic

mmvic

New member
Re: ground issue. G108 & G109

wow thanks wyo, I ll def check that. I was thinking maybe the grounds are intermittently comming in contact (maybe they have hairline cracksin insulation) via bat wire running to the altinator causeing the to become charged.
 
mmvic

mmvic

New member
Re: ground issue. G108 & G109

on further inspection i see now that the g100 ground is NOT hooked to battery since i relocated it in the bed. Wyo u r smart!
 
WyoSyclone

WyoSyclone

Active member
Re: ground issue. G108 & G109

mmvic said:
on further inspection i see now that the g100 ground is NOT hooked to battery since i relocated it in the bed. Wyo u r smart!
Click to expand...

I was gonna ask if you'd relocated your battery... let us know what happens once you get it hooked back up ;)
 
T

TurboTYPHOON

New member
Re: ground issue. G108 & G109

I had my engine replaced and they forgot to hook up the G100. I fried 2 alternators in 6 days. Battery also relocated to the back. but my g108-09 were hooked up.
 
mmvic

mmvic

New member
Re: ground issue. G108 & G109

Well i ran the new ground from the battery to the block and no difference... I checked my theory about the grounds getting power some how and that checked out ok, so Im still stumped. Maybe I'll just bit the bullet and try a new ecm. Here are two datamaster logs showing the crazy stuff going on with the grounds connected then disconnected. Check out the code 53 i get at the end of the first one
http://www.mediafire.com/file/lr3vi3s7l7rcsat/newbatterygroundwithothersconnected.uni (with 108&109 connected)
- - - - - - -- - - - - - - - - - --- - - - - - - - - - - -
http://www.mediafire.com/file/onaxr6zfv9i8fq9/newgroundsdisconnected.uni (w/o 108&109 connected)
 
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