I was reading the install instructions and they say to remove the fuel pump fuse and fan fuse before flashing the PCM, why do you have to do that?
SCT Xcal 2 ?
- Thread starter '13_ImpactBlue_GT
- Start date
04YELLOWGT
Active Member
I thinks its just incase they would some how short out, that they wouldnt be responsible for it. I didnt when I flashed mine
Don 95Vert
Founding Member
Because if the battery voltage drops below a certain point your EEC dies. You want to limit the drain on the battery while flashing - radio off, fan off, FP fuse out. On a GT it isn't too critical IF you have a good battery to begin with - and many people do not - but on a car like an SVT Focus where it takes 12 minutes to flash - you HAVE to do all that plus put it on a charger when flashing.
Don 95Vert
Founding Member
It has nothing to do with the bat. Ford PCM s have a nasty habit of cycling the fuel pump and injectors during a reflash. This could be random. If it happens then you could fill a cylinder very quickly and get hydro lock when you go to start the car. Bye Bye rod. Always disable the fuel pump when doing a flash by pulling the fuse or unpluging the inertia switch in the trunk.
Don 95Vert
Founding Member
Well, seeing as how I wrote the product documentation for SCT for the XCal 2 and am co-author of SCT's two tuning manuals, I think I have a bit more insight into why you need to remove the fuses than the average person posting here. Don't wish to argue, but I thought I'd post to give the official SCT answer as to why the fuse(s) should be removed. I too have flashed cars without pulling the fuse - but if the EEC dies during the reflash, it'd be my fault, not SCTs.
The fuel pump is cycled, NOT the injectors. On a return style car it just dumps the fuel back into the tank - and a returnless car, it just shuts off when pressure drop across the injectors is at the predetermined point.
The fuel pump is cycled, NOT the injectors. On a return style car it just dumps the fuel back into the tank - and a returnless car, it just shuts off when pressure drop across the injectors is at the predetermined point.
Don 95Vert said:
Not only do you know more than the average person (me) but you know more than the Tech Reps at SCT. I called twice with the same question and was given the same answer both times. I didn't accept it the first time but both calls were answered the same by different reps. I quess they didn't read your manual
Anyway, they insist that the danger is hydrolock even with a returnless system and that the injectors can open (cycle)
Furthermore, they claim that if you bat dies during a reflash the worst case scenario is your stock tune did not get saved and you would have to get the pcm reflashed by the dealer and start again but the tuner is designed to recover and the pcm is not permanently damaged. I think they need to get with your program before they screw someone up. I stand corrected.
Don 95Vert
Founding Member
Fast02 said:Well then maybe you can rewrite the manual to show where these fuses are...
In the newest XCal 2 SF - the manual is 22 pages long and DOES show where the fuses are!!
With the XCal 1's they didn't have removing the fuse as an option, but revised it with the Xcal 2. I have no idea why the techs gave out that info... I'll ask next time I talk to them...
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