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e.c.m ground



does anyone know where the e.c.m ground wire is located
in the engine compartment

Ok, Ready...
Start chanting...
Ohmmmmmmmmm, Ohmmmmmmmmmmmm!

I'm assuming Coupe...

There are 3 grounds going to the ECM
( at this point)

All Black/white tracers ( crkt 450 )
on Pins
D3 & D10 ( on C1 )
A12 ( on C2 )
These are the 2 connectors on the ECM

C1 is the BIG connector (16 pin dual) Series "C&D"
C2 is the small connector (12 pin dual)Series "A&B"

These wires splice ( in the harness) at S 111
( for the Mass airflow sensor/Mass airflow relay/fuel pump relay/& tranny position sensor, assuming automatic)

The S111 splice is buried in the harness at the firewall feed thru behind the right hand cylinder head ( Not a pretty job)

Which ties to......
G-104 ( left side of engine by Oil temp sensor,
Big godzilla lug with other grounds on it)

In addition

The G 101/G-104 jump from the Engine Block ground Braid to the FRAME ground to the Battery Neg Small lead. The FRAME point is about under the Vac booster for brakes ( a little foward ) this ground point always gets rusted up!

Foot note
There is a TAN wire on Pin D-6 of the ECM connector ( C-1 ) which has a home run to the G-104 ground point.

There should be a total of 5 Big lugs on the LEFT side of the engine.

Braid to ground
Batt big Neg cable
& 3 wiring harness lugs
on the engine side (7 wires I think) on the G-104
(engine side ground point)

Hope this helps

( You can stop chanting now!)
yeah i think that pretty much covers it. my vette is an 86 coupe.
hoping i have a grondig problem. not getting reading on my scan tool from the MAF,TPS, IAC, and the car is running in an constant open loop, thanx for the info vigman
Your Welcome

Wiring is always a pain....

but at least it's not like Lucas wiring.


Do you know why the Brit's drink warm beer?

Cause the fridges are wired by Lucas....

Oh well

Ohmmy that's a real gasser. :L

Sorry, I resisted but for only so long.

cheers :beer
shocking , simply shocking.

But the theory is well grounded.

-MIke :D

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