I have just purchased a Knock Control Unit for a 1984 EA81 Turbo Engine. The wiring from the Unit is sheaved in Black Plastic and goes to a Black 8 Pin Plug. Just before the Black plug there is another wire, Red with Green Stripe, that goes to a White 2 Pin Plug.

Can anyone tell me what the Red/Green Wire is for and where does it go to?

Regards No Culpa

does it go to the knock sensor ?

 

One wire , goes to a two pin plug. Just one wire to one pin? Are these round pins, flat 6mm flat spade, 3mm flat spade.

 

Has the kcm got a part number or makers name or logo on it? gold zinc metal box or black plastic box?

 

Knock sensor got one pin or two in it? Round pin ? Colour of knock sensor ?

 

May as well try give all the wires colours and positions to see how it matches up with the 85.86 EA82T version

 

try this link, look at diagram supplied by a Subaru Parts manager - see if it helps

 

http://www.ausubaru.com/forum/showthread.php?t=11260&highlight=diagram+knock+sensor

Edited April 21, 201411 yr by jono

I have just purchased a Knock Control Unit for a 1984 EA81 Turbo Engine. The wiring from the Unit is sheaved in Black Plastic and goes to a Black 8 Pin Plug. Just before the Black plug there is another wire, Red with Green Stripe, that goes to a White 2 Pin Plug.

Can anyone tell me what the Red/Green Wire is for and where does it go to?

Regards No Culpa

 

It goes to the high altitude switch located in the ECU.(pin 18)

It grounds itself above 1400m,signaling the KCU to advance timing 5 degrees.

Hey thanks guys for the replies, the control unit is genuine 1984 EA81T Subaru. Part No is 420887100 and is metal, gold in colour, made by Hitachi.

The single wire (Red/Green) goes from KCU to a black 2 X 6mm flat spade plug. The Red/Green wire is then looped or bridged from one blade to the other. The round plug from the KCU I have all figured out, so there are no worries there.

The High Altitude Switch makes sense, the only confusing thing is that my Service Manual shows a Green/White going from the H/A Switch and goes to pin 17.  To make things worse there is no H/A Swithch on engine that I have.

But my Manual is for the 1983 Subaru 1800 4WD Turbo, so they could have changed the colour of the wiring for the 1984 Model.

Thanks once again

83s and 84s are different.

What year do you have?

 

If you have an 84 ECU,you have a hgh altitude switch.It is inside the ECU on pin 18.

Pin 17 will be blank for 84.

 

83s mount the switch external to the ECU.

I've got a 84, thought that they could have been different, all make sense now. Thanks for the help naru.

Probably should start looking for a 1984 Turbo Service Manual, the 1983 Manual has the only one going when I was looking before.

Regards Non Culpa