VIII patch to reset fuel trims?
Evolving Member
Joined: Jun 2005
Posts: 282
Likes: 5
From: Kuala Lumpur
That definitely the whole point reset the fuel trim and I just suggest something easier than disconnecting battery. Can't imagine I got to re-tune my favourite radio channel and clock each time battery reset. 
I've actually considered just wiring in a normally-closed momentary switch to the power line for the ECU; there's been more than a few cases where I'd have liked to wipe RAM and start from a completely fresh boot, but digging the ECU harness out of the dash isn't typically very convenient.
Of course, neither is rooting around under the dash, installing yet another switch. I'm running out of room for attractive installs of switches and LEDs.
Of course, neither is rooting around under the dash, installing yet another switch. I'm running out of room for attractive installs of switches and LEDs.
Evolved Member
Joined: Mar 2008
Posts: 730
Likes: 3
From: Lattitude 48.38°, Longitude 17.58°, Altitude 146m = Slovakia, for common dude
logic, tephra can you write a patch?
for 94170015:
create function which checks 0x10 at variable FFFF8DC8
if bit is set calls sub 14302 and at the end sets r0 to 1
replace function reference from sub 20D02 to the offset of new one at 8B98
then clearing CEL would clear trims even in case there is no CEL.
for 94170015:
create function which checks 0x10 at variable FFFF8DC8
if bit is set calls sub 14302 and at the end sets r0 to 1
replace function reference from sub 20D02 to the offset of new one at 8B98
then clearing CEL would clear trims even in case there is no CEL.
Last edited by acamus; Nov 4, 2009 at 10:16 PM.
Evolved Member
Joined: Mar 2008
Posts: 730
Likes: 3
From: Lattitude 48.38°, Longitude 17.58°, Altitude 146m = Slovakia, for common dude
Nobody wants to write a patch 
, I had to do it manually in hex as I do not have build environment set yet .....
Here it comes fully untested with no warranty for 94170015.
HEX
, I had to do it manually in hex as I do not have build environment set yet .....Here it comes fully untested with no warranty for 94170015.
Code:
00008B98 .data.l sub 39000 00008BF8 .data.l sub 39000 sub 39000: 00039000 mov.l r14, @-r15 00039002 mov r15, r14 ; 00039004 mov.l @(h'14,pc), r10 ; FFFF8DC8 00039006 mov.w @r10, r10 00039008 extu.w r10, r0 0003900A tst #h'10, r0 ; 0003900C bf loc_39014 0003900E mov.l @(h'10,pc), r0 ; sub 14302 00039010 jsr @r0 ; sub 14302 00039012 nop 00039014 mov #1, r0 00039016 mov.l @r15+, r14 00039018 rts 0003901A nop 0003901C .data.l FFFF8DC8 00039020 .data.l sub 14302
Code:
00008BF0 00 02 0F D4 02 08 FF FF 00 03 90 00 02 10 FF FF 00008B90 00 02 0C D0 01 80 FF FF 00 03 90 00 02 01 FF FF 00039000 2F E6 6E F3 DA 05 6A A1 60 AD C8 10 8B 02 D0 04 00039010 40 0B 00 09 E0 01 6E F6 00 0B 00 09 FF FF 8D C8 00039020 00 01 43 02 FF FF FF FF FF FF FF FF FF FF FF FF
Last edited by acamus; Nov 4, 2009 at 10:20 PM.
Sorry for not getting a chance to look at this, acamus, but your patch looks basically right to me. Also, 96530006 is basically the same thing, but you'd need to change sub_14302 to sub_14172.
I'll try to test this today when I step out for lunch, it certainly looks straightforward enough.
I'll try to test this today when I step out for lunch, it certainly looks straightforward enough.
Evolved Member
Joined: Mar 2008
Posts: 730
Likes: 3
From: Lattitude 48.38°, Longitude 17.58°, Altitude 146m = Slovakia, for common dude
My only concern is whether the flag at FFFF8DC8 stays set long enough to reach engine on/off checks @8B98 and @8BF8
otherwise more changes are needed.
otherwise more changes are needed.
Last edited by acamus; Nov 4, 2009 at 10:15 PM.
Aaron, just let me know when you port jcsbanks' SD patches to 96530006, and I'll be happy to give up my fuel trims. (Which reminds me, I really need to get jcs' DMA logging patches added to 96530706 at some point, I really miss the logging rates I had with that.)
acamus, looks like I'm not going to be able to test this this afternoon; earliest I'll be able to look at it is tonight. So, someone else might want to take a quick crack at it if they're in a big hurry to know if this is workable.
(I still think hooking this into tephra's map switching is probably a good idea as well, though; switching between E85 and E10 usually results in at least a little bit of a swing in trims for me, despite having things dialed in pretty well.)
(Which reminds me, I really need to get jcs' DMA logging patches added to 96530706 at some point, I really miss the logging rates I had with that.)acamus, looks like I'm not going to be able to test this this afternoon; earliest I'll be able to look at it is tonight. So, someone else might want to take a quick crack at it if they're in a big hurry to know if this is workable.
(I still think hooking this into tephra's map switching is probably a good idea as well, though; switching between E85 and E10 usually results in at least a little bit of a swing in trims for me, despite having things dialed in pretty well.)
Thread Starter
Joined: Jun 2007
Posts: 2,706
Likes: 15
From: Lexington Park, MD
I can't do it today either... I am still on the 0011 rom anyway as i do not use map switching... I have a patched 0006 rom already, just haven't had a chance to didldle with it...
Evolved Member
Joined: Mar 2008
Posts: 730
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From: Lattitude 48.38°, Longitude 17.58°, Altitude 146m = Slovakia, for common dude
Now that we know that some actuator commands are not used in some ROM's, we have the opportunity to write patch that uses spare "dedicated" command for doing this. Fast_Freddie are you still interested? What is your ROM ID?