Orange wire memory power question

[PaulRV6]

What exactly does this 12v orange power wire do? Will the engine run without it connected? It goes right to the ECU but what memory does it hold? Thanks

 

[TurboTGuy]

It is the power wire to the ECM. The wire itself doesn't have any "memory". The ECM does.

Turbo Tweak sells a Tune Saver that is wired in between the battery and ECM via that orange wire to provide power to the ECM if the battery goes dead, but the wire itself is only for dedicated power to the ECM. The ECM has to have power all the time or it will revert back to factory settings if you have done any tuning via powerlogger or scanmaster.

The car will not run if it's disconected.

 

[pacecarta]

the ecm does have memory , besides SES codes if any it retains learned blm data
as mentioned car wont start without the orange wire supplying 12v and will clear SES and blm data when disconnected
if you have a tt chip and changed any of the fuel or timing settings they will reset as those are stored in the blm data

 

[PaulRV6]

Ok thanks. Do you know what the amp rating is of the fusible link on the orange wire? The wiring diagram shows fusible link J. I just want to put a temporary fuse in line to be on the safe side.

 

[salvageV6]

It's a .5mm fusible link 20 awg.
A 3-5 A fuse and holder should work or make the right one up.

https://www.oreillyauto.com/detail/c/standard-ignition/standard-ignition-20-gauge-fusible-link-universal/std0/cw20f

 

[TurboSmart]

So if that orange cable is just for "memory", which other cable supply power to the ECU?

I am tracking a ECU voltage drop after doing the Casper fuse link kit and seems that I messed up that install as I have low voltage at the ECU, so low that affects sensor reading (TPS and bat voltage low, via ScanMaster)

 

[salvageV6]

ECM/IGN fuse.

 

[TurboTGuy]

The orange wire is the only power source for the ECM, as far as I am aware. No alternate source.