Which wire should I use to kill the ecu? Is there any negative effects to resetting the ecu EVERYTIME you turn off the car? I have a switch so I can check codes from the drivers seat, but I would also like to be able to hit a switch to re-set the ecu. This would also double as a ecu shut-off for break-ins. Although visible, it's still slows the theft process. Any help is appreciated.

 

The ECU on my 94 teg has only one constant power into it, the 7.5A "back up" fuse, if this fuse is blown, it does not prevent car from running, the main ECU fuse 15A, [hot at all times] does not supply power to
ECU unless ign. is on, [ runs through the "PGM-FI Main Relay" pack (ECU power relay)].

Installing a switch on that power wire. [before relay] would work, not sure if it's the same on a 88 "rex".

My teg also has a hot when cranking fuse, [starter signal 7.5A under dash fuse box], it supplies power to the ECU and the "PGM-FI Main Relay" pack (fuel pump power relay) when cranking to start, a switch on that line would also work as a "kill" switch

Looking at my wiring guide, it looks like the ECU is reset every time ign. is turned off anyway, I don't see any constant power into ECU except the 7.5A backup fuse, it is the memory for the HU, so maybe it has something to do with memory in the ECU, but as I said it will not keep the car from running if removed/blown. 94

 

The 7.5 backup fuse is the one that retains the memory. The manual says to pull this fuse for 10 seconds to reset the computer's memory for different repairs ie. adjusting the idle screw.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by suspendedHatch &raquo;</TD></TR><TR><TD CLASS="quote">The 7.5 backup fuse is the one that retains the memory. The manual says to pull this fuse for 10 seconds to reset the computer's memory for different repairs ie. adjusting the idle screw.</TD></TR></TABLE> But it won't keep the car from running. 94

 

just put a switch on every wire, its give you 40 hp

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fcm &raquo;</TD></TR><TR><TD CLASS="quote"> But it won't keep the car from running. 94</TD></TR></TABLE>

Yeah I know, you already covered that. That fuse was blown when I bought the car, who knows for how long. Replaced it, started getting better mileage and smoother idling within a day or two.