Extra pigtail on turbo ECU

[rasmussenbc]

Hey all,

I have searched and also posted on other forums looking for an answer to my question, but haven't received any straightforward answers, just guesses, and some way off.

I am trying to finish my 7mgte engine swap. I have an 88 N/A supra, yellow plug 88 7mgte engine harness, and yellow plug 7mgte ECU. There is no place to plug in the extra pigtail coming off the back of the turbo ECU.

The TSRM states that the 3 pins in the pigtail are for headlight relay, defogger relay, and turbo indicator. I can easily repin the headlight and defog relays, but was curious as to what I needed to do for the "turbo indicator."

I have had some really off-the-wall responses so far on other forums. The most common response is that the pigtail is actually for HAC, which is incorrect unless the repair manual is lying to me.

Please help, and thank you for your responses.

 

[BryanDyer]

Can you post a pic?

 

[supraguy@aol]

So you're talking about the actual plug that's hanging off the back of the ecu, and not a socket in which to install a plug, correct?
I see the same pinouts on my diagram, but looking at my ecu, I actually have 5 wires/ pins in that plug...wierd...

 

[3p141592654]

The Turbo Indicator was never used in USDM cars since they all get a boost gauge. In other markets, it is used to turn on a dash LED that says "Turbo" approximately when the turbo is spooling. Its a guess though, based only on engine rpm and load. You can leave it disconnected.

 

[rasmussenbc]

So you're talking about the actual plug that's hanging off the back of the ecu, and not a socket in which to install a plug, correct?

yes thats what im talking about.


To 3p141592654,

Thank you, thats exactly the type of response i was looking for. So was that the GA70's that had the turbo indicator light?

 

[supraguy@aol]

Hey Pi-

What is the significance of the extra two wires in my pigtail?

 

[pogoism9]

im prety sure thats for the HAC (High Altitude Compensation) sensor that was later relocated internal to the ECU in 1989