pgmfi.org

Hacking up Honda's ECU
It is currently Wed Sep 24, 2025 10:55 pm

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 17 posts ]  Go to page 1, 2  Next
Author Message
PostPosted: Wed Jan 10, 2007 4:25 am 
Offline

Joined: Fri Jan 05, 2007 9:10 pm
Posts: 749
I just bought a JDM Auto P30 ECU a P30-901 (I used to have a P30-900 i dunno what the difference is here)

anyways it doesn't come with a latch chip like the wiki says that A/T ones do
Also some said that the A/T JDM ECU is ready to chip but this one has no latch, no socket, no C49 C50 or C91 and C92. (I think the OKI and ST variants of the boards are different) look in the wiki and the ST board like my one doesn't have a latch but the OKI one does. I feel M/T or A/T is not the answer its actaully different varaints of the board.
Allthese items I mentioned have dotted lines around them including the J1 which shows that they all should be altered or added in order to chip. (cheers honda)

Some pics of the ECU
Code and Chip+latch space
Image
the full ECU
Image

So I read you have to reduce the resistance of RP18 from 2.4 to 1.4 to convert to manual (why not a software fix :cry:
HOWEVER my RP18 says '472' on it and i measured the resistance to be 1.8K. What do I do, is this normal???
here is the pic
Image

also the wiki says cut J4 on the front of a JDM ECU to enable full duplex datalogging. However there is a resistor in J4 with '000' on it. DO I remove this??
Pic below
Image


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Wed Jan 10, 2007 9:23 am 
Offline

Joined: Thu Jun 09, 2005 3:53 pm
Posts: 750
Location: Bonny Scotland
As you can see, not all a/t ecu's come with a factory external rom.

There is no difference between the oki and st boards....the board type is printed under the "T3J-E" silk screen, I have only ever seen the last four digits ranging from 1500 to 1503 on jdm ecu's.
This is the only way of determining board differences/revisions.

472=4700 ohm, you have to de-solder the resistor in order to check its value.
I think it is a typo in the wiki cause I personally have never seen a 2.4k ohm resistor in RP18.
Simply unsolder RP18 and replace with a 1.4k ohm resistor to convert.
I have done this with success, I couldn't find a 1.4k ohm smt resistor so have always used 1.5k.
This worked no problem.

J4 is a jumper, 000 means it has no resistance, remove it to enable full duplex comms.
If you are careful removing it, you can reuse it to jump J1.


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Wed Jan 10, 2007 4:39 pm 
Offline

Joined: Fri Jan 05, 2007 9:10 pm
Posts: 749
ah cheers, you have cleared up everything. How do we get them to change the wiki to make it less confusing for newbies like me?

P.S one more question:
so i plugged the ECU in and got a solid CEL with code 19 A/T and code 22 VTP. this is on a type R motor in a OBD1 civic with no VTP and a manual.
anyways i started the car and after about 30 seconds got a bouncing or 'hunting' idle.
Im worried the ECU won't control idle properly because ITR motors do not have the FITV on the TB with water flowing throw it like the b16a2 civics do that this P30 ECU is from, Instead the cold idle is controlled by the OBD2 ECU on the ITR. So it seems the P30 mechanically controls cold idle and the OBD2 ECU controls it. THEREFORE: will I ever have cold idle using this chipped ECU?
In relation to RP18: That makes sense why i was getting 1.8k and not 4.7k on my multimetre cause it wasn't desoldered. (I too have only found 1.5K resistors to buy)

any tips on desoldering and resoldering these surface mount resistors?
Do u heat up both pads and then use pliers or similar to remove them while the solder is still a liquid?

Yeh i thought that the ST and the OKI chips may dictate which has the latch as this is the case in the picture on the wiki.
But you say its the board revision number that dictates this? Ill have a look at my one

cheers once again


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Wed Jan 10, 2007 5:49 pm 
Offline

Joined: Thu Jun 09, 2005 3:53 pm
Posts: 750
Location: Bonny Scotland
Yeah, I had meant to add something to the wiki myself, all you do is log in under your user name to add or amend info.

Code 19 will disappear after you convert RP18.
VTP seems to be a bit of a problem...one hardware fix for it is to connect a4 to d6 (off the top of my head).
The latest version of Crome now has a vtp disable option.
Iirc you need to earth the vtp from the ecu and add the plugin.
I do not know if this works properly as I have not had the chance to test it out myself.

The bouncing idle seems to be caused by the a/t binary, I have experienced this myself after plugging in a a/t ecu to my civic.
Again, it should all come good after the conversion.

I sucker the solder from the pads first and then use two temp controlled, fine tip soldering irons to remove the smt components.
One on each end of the component and lift....be careful cause it is very easy to lift the pads if either the heat is to high or the solder is not completely molten.

I think the Oki and ST chips are electronically identical, I think it was simply down to who could supply them at the time.
This is only my opinion though.


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Wed Jan 10, 2007 6:02 pm 
Offline

Joined: Thu Jun 09, 2005 3:53 pm
Posts: 750
Location: Bonny Scotland
Oh yeah, fitv question.....could be a problem for you on cold start.

OBD2 controls cold start with the IACV, the OBD1 IACV doesnt seem to be able to control it without the FITV.

I bored out a stock sir2 t/b to fit a B18C6 swap in a 95 sir2 cause I could not get Crome to deal with the cold starts.

I think I read somewhere on here that Calvin had managed to eliminate the FITV and control cold start with the advanced tables in Crome.
Dont quote me on it though. I could be mistaken.


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Wed Jan 10, 2007 6:14 pm 
Offline

Joined: Fri Jan 05, 2007 9:10 pm
Posts: 749
so what you are saying is all I have to do is change RP18, and wire A4 to D6 and that ECU should run the car will no CEL and NO bouncing idle when warm? But my cold start may be messed up?

Note: I used to have this ITR motor in a 1993 integra XSi DA6 with a OBD1 PR3 ECU. It ran my ITR motor perfectly on cold start and idle and it would have been programmed for a OBD1 IACV and FITV, Strange eh? Apart from it giving a code 22 when i vtec'd cause no VTP. I soon made a OBD2 conversion harness an ran my ITR ECU.

P.S that fix in crome doesn't work with grounding the VTP it eliminates the CEL but apparantly the high cam maps do not switch over, or conversly the high cam maps switch on but do not turn off :cry:

I don't think there is a perfect fix for cold start other than swapping in a FITV and a OBD1 IACV (which both do not fit on either the ITR manafold or the ITR TB (which i have had bored)

Basically I think im screwed, cause there is no way im taking out my ITR IM and TB just to fix an idle that should be fixed with software as other aftermarket ECU's can do.
I may just set the fuel and ignition values the same in the low areas which isn't really ideal but will fix the idle

your comments please 8)


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Wed Jan 10, 2007 7:59 pm 
Offline

Joined: Thu Jun 09, 2005 3:53 pm
Posts: 750
Location: Bonny Scotland
Quote:
so what you are saying is all I have to do is change RP18, and wire A4 to D6 and that ECU should run the car will no CEL and NO bouncing idle when warm? But my cold start may be messed up?


Yes.

Quote:
Note: I used to have this ITR motor in a 1993 integra XSi DA6 with a OBD1 PR3 ECU. It ran my ITR motor perfectly on cold start and idle and it would have been programmed for a OBD1 IACV and FITV, Strange eh? Apart from it giving a code 22 when i vtec'd cause no VTP. I soon made a OBD2 conversion harness an ran my ITR ECU.

P.S that fix in crome doesn't work with grounding the VTP it eliminates the CEL but apparently the high cam maps do not switch over, or conversly the high cam maps switch on but do not turn off


Interesting....PR3 eh, I will have a chance to suss it out myself in a month or so with a itr swap.
Shame about the vtp plugin, I thought John had sussed it out this time. Guess that is something else that needs looked at in Crome.

Quote:
I don't think there is a perfect fix for cold start other than swapping in a FITV and a OBD1 IACV (which both do not fit on either the ITR manafold or the ITR TB (which i have had bored)


It will take sombody with a sound working knowledge of the iacv control routines to crack this problem.
I see no reason myself why the cold idle could not be controlled properly with obd1 IACV.
Unfortunately I suck at assembly.

Quote:
Basically I think im screwed, cause there is no way im taking out my ITR IM and TB just to fix an idle that should be fixed with software as other aftermarket ECU's can do.
I may just set the fuel and ignition values the same in the low areas which isn't really ideal but will fix the idle


Yes, I understand where you are coming from. I guess the best thing to do would be to try it all out and see what happens.
I will be in the same position soon, If I encounter the same problems then I guess I will have to try another ems if things dont work out as they should with Crome.


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Wed Jan 10, 2007 9:38 pm 
Offline

Joined: Fri Jan 05, 2007 9:10 pm
Posts: 749
howsit going just went to my local honda shop around the corner. They are one of the top honda builders in New Zealand. Anyways they do this to tune cars

.A4 wire to D6 vtec soliniod to vtec pressure swtich to fix VTP

as for chipping: they only add the socket+chip+latch 373 chip bridge J1+ remove J4. They have never added the capacitors.

With the auto to manual thing: I checked some manual P30 they had a RP18 value of 000 which means jumper only. They think you just remove RP18 altogether and it works. So adding a 1.4-1.5k resistor may not be needed. The manual runs a jumper so maybe just jumper it or try removing?

as for idle issues: they say that everyone with issues just doesnt know how to tune properly and you can tune around it. Whats more just as I have they said they have run many cars that dont have FITV on stock OBD0 computers even and they had a nice idle. This shows that I ran my stock OBD1 ECU on my ITR motor with no FITV and it idled nice.

These guys I was talking to a very onto it, they dyno tune then road tune after. It takes them like 10-15mins max to chip one also! They said use a cleaner to get the film off the board before soldering. I think i need some quality soldering gear like a smaller tip and a solder sucker


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Thu Feb 22, 2007 6:31 pm 
Offline

Joined: Thu Nov 25, 2004 7:49 pm
Posts: 40
Location: fife
I've been reading this post with interest. I have a Spoon sports chipped P30-900. All the things you have discussed on here match (J1 is jumpered), the value of resistor RP18 is 4700 and so on, only the baord revision is T3J-D and it ends in 1500. Not sure what that all means.

I was looking to convert this to a manual and see that if I jump or stick in a 1.5k resistor into RP18, it'll run as a manual. the only thing is, will I need to burn a new map for a manual or will it run ok with the Spoon chip still in it? I'm guessing it'll need a new map :? . Obviously I don't want to go peeling stickers off the Spoon chip as that'll devalue it.


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Thu Feb 22, 2007 8:22 pm 
Offline

Joined: Fri Aug 20, 2004 6:33 pm
Posts: 2273
Location: chicago burbs
the auto-manual selection is done in the hardware of the ECU, the chip should remain the same.

idle smoothly with ITR swap, has been done. It takes some time to get it right though. Cold start up it tends to idle at 1100 instead of 1500 but it works.
Boxing in the idle areas with the same ignition and fuel values tends to get rid of the hunting idle and adjusting the IAT/ECT as well as start up values gets the cold starts working right.


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Thu Feb 22, 2007 9:29 pm 
Offline

Joined: Thu Jun 09, 2005 3:53 pm
Posts: 750
Location: Bonny Scotland
I concur relic1.
Very recently swapped a c6 into a eg6 using obd1 spool valve, itr inlet/tb and iacv.
Was able to map idle with relative ease, it is not as stock but certainly acceptable. Cranking, post and temp corrections took a while to suss out.
Ambient temps have been all over the place recently, snow some mornings...double figure celcius on others and it still behaves itself :o
When time allows I am going to make an adapter plate for a obd1 iacv and give that a go as well just for s&g.
I would also like to try it with my neptune fitted and see what that is like.


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Wed Apr 04, 2007 11:19 pm 
Offline

Joined: Fri Jan 05, 2007 9:10 pm
Posts: 749
Auto to Manual I re-wrote the wiki: You remove RP17 and jumper RP18 with a wire.
then its manual.
check chipping a P30 in the wiki.


I plugged my P30 into my car running a B18CR cold start was fine, only thing i noticed is once warm the idle is about 680-700 and with the lights on sometimes it hunted but id blip the throttle and it would stop.

Iv tried increase idle speed and ECT verses idle speed and it made no changes at all? Maybe crome doesn't work in the advanced tables.


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Mon Apr 23, 2007 11:51 pm 
Offline

Joined: Mon Oct 30, 2006 12:04 pm
Posts: 14
Coupe-r wrote:
Note: I used to have this ITR motor in a 1993 integra XSi DA6 with a OBD1 PR3 ECU. It ran my ITR motor perfectly on cold start and idle and it would have been programmed for a OBD1 IACV and FITV, Strange eh? Apart from it giving a code 22 when i vtec'd cause no VTP. I soon made a OBD2 conversion harness an ran my ITR ECU.


Recently I tested a P06 converted to VTEC and tested on a JDM XSi integra and the idle just started bouncing, ran OK, but with the chipped P30 or PR3 there was no problem :shock:


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Tue Sep 25, 2007 1:24 am 
Offline

Joined: Fri Jan 05, 2007 9:10 pm
Posts: 749
I later fixed these issues bu changing the advanced idle tables and the cold resume idle i think. Setting the warm idle to 850rpm.

Fixed the bouncing idle with the IACV duty cycle adjustor since im running a OBD2 IACV with a OBD1 ECU


Top
 Profile  
Reply with quote  
PostPosted: Sun Feb 03, 2008 12:22 pm 
Offline

Joined: Sun Feb 03, 2008 11:53 am
Posts: 2
So JDM p30 a/t ecu can convert m/t?


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 17 posts ]  Go to page 1, 2  Next

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 14 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group