RomRaider

Briefly, the process to create a fuel pump duty table for a 32-bit ROM goes like this:

Do the 32-bit setup described in the how-to thread.
Find the SSM function that retrieves fuel pump duty.
Find the variable that function returns.
Look for XREFs to that variable.

In A2WC522N (05 LGT) there are only 3 XREFs:
The first initializes it to zero.
The 2nd is the SSM routine.
The 3rd is a function that checks some switches and sets it to 0, 33, 66, or 100.

In A8DH201X (06 WRX) there are two XREFs:
The first is used by two functions - one sets the FPDC to 100%, the other sets it to 33, 66, or 100.
The second is used in the SSM routine.

A table can be defined for the 33 and 66 values. Setting both to 100 will cause the pump to run at 100% all the time. Or you could set them 50 and 75 for example, if you just want a modest increase from the 33 and 66 settings.

A8DH201X:



A2WC552N:



If EcuFlash is open, you'll have to close it and reopen it to see the new table. You should see values of 66.7 (it's really 66.666666etc but it gets rounded up) and 33.3.

If you see any other values, don't touch them. That means the table definition is incorrect, and changing the wrong part of the ROM will have undefined results. Like bricking your ECU or blowing up your motor.

EDIT: I renamed one of the values from High to Medium. There's also 100% of course, so it doesn't make sense to call the 66% value High.

Awesome stuff, been tracing through the logic for the 16 bit ecus, namely the A4TE002C and A4TJ1X00 to try and get similar, currently stuck at finding out what word_20B1A in the A4TE002C rom is all about. Sure would appreciate some help on that. Thanks for all the nice work!

Sorry, I don't know anything about 16-bit ECUs, I've only worked on 32-bit. The A8DH201X WRX ROM that I did the fuel pump table for is actually the first ROM I've opened other than the one from my LGT.

Thanks NSFW, this is a great addition to the 32bit arsenal! Here is a list of the data locations for all USDM 06+ wrx and USDM 04+ STi.

06 WRX A8DH201X - 3D4E4
07 WRX A8DK100X - 3E218
08 WRX AZ1E401A - 44664
09 WRX AZ1G401V - 45328
10 WRX AZ1G701V - 47D44

04 STI A2ZJ710J - 31E24
05 STI A2ZJB11J - 3402C
06 STI A2ZJE11J - 34D98
07 STI A2UJ000J - 3B704
08 STI AZ1G202I - 44E24
09 STI AZ1G202I - 44E24
10 STI AZ1G702I - 47A30

I tested the A8DH201X and it works perfectly. Thanks again.

Works on 07 wrx.

08 STI AZ1G201G EUDM - 43450
08 STI AZ1G202G EUDM - 43450
09 STI Z1G20000 EUDM - 43450

Wow, you guys rock! The STI and WRX are pretty well supported now.

If any LGT owners have a problem that might be fixed by adjusting the fuel pump duty cycle, I will find the tables in your ROM. However please don't ask me to find the table just for the sake of having it show up in EcuFlash - I'd really rather be spending my time figuring out new timing compensations, closed loop fueling controls, and stuff like that. But if you have an issue, send me a PM with your ROM and a description of the problem.

Anyone want to take a crack at it for a 16-bit ECU?

The car runs good fuel trims everywhere but is running really lean under boost. My fuel pump doesn't seem to fully kick in till the MAF is in the ~80+g/s range... That would be fine except I've halved my MAF scaling which means my actual airflow is in the ~160g/s range before the fuel pump runs at 100%. I'm currently searching through trying to find some info on when the fuel pump goes to 100% for stock roms.

A4T520F - 16-bit 04 USDM WRX

Thanks for your help!

Thanks NSFW - very cool. '05 LGT owner too (Legend). I'm curious as to the utility of adjusting fuel pump duty cycle... if anyone has solved any problems by manipulating these tables I'd be curious to hear about it.

If you're running the A2WC522N ROM, you can use the XML I included in the first post. To the best of my knowledge that's the most recent 05 LGT ROM.

The only people who I think will really care about this are people with aftermarket fuel pumps that don't work properly with less than 100% power. 06rexwagon said his pump runs much quieter at 100% than it did at 33 or 66, for example. And some pumps come with instructions that say not to use them with anything less than full power.

What power requirement do walbros 255 have?

Very often it fails at 33% duty.
Try to set 66 instead of 33 and 100 instead of 66%.

I wish this as well!!

I think I have these 02-05 on my laptop. I am just about to switch back to my Bosch 044 so I was just going through the XML again.