obd2 swap
obd2 swap im getting annoyed i figure its something small and trust madz28 but i cant figure it out....can any1 help me, i already posted this in local forum texas section of ls1tech and cz28
im goana remove a few words tired of typing..
i installed the obd2 conversion pcm...and knock sensor...have a ses light so i
need to scan it
went to that junkyard got a obd2 connector and tried wiring it in
B 2.
M 9.
G 8.
a power wire going to 16.
5-a
hook up a scanner and it cannot link to the computer.....
is there a way i can check voltages at the connctor to see if it has reading there???
i really just need to scan this
im goana remove a few words tired of typing..
i installed the obd2 conversion pcm...and knock sensor...have a ses light so i
need to scan it
went to that junkyard got a obd2 connector and tried wiring it in
B 2.
M 9.
G 8.
a power wire going to 16.
5-a
hook up a scanner and it cannot link to the computer.....
is there a way i can check voltages at the connctor to see if it has reading there???
i really just need to scan this
TECH Addict
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From: The beautiful Kingdom of Bahrain
You left out so much it's hard to know where to begin. Dont you have to use a 96-97 wiring harness to go OBD2 because of the crank sensor etc? I thought down grading was easy but upgrading was tough? I also would like to know what made you go OBD2. OBD2 has some really cool stuff out there but I dont think it's worth the hassle of swapping over.
What you need is the following:
PCM Blue 7 goes to OBDII Pin 2 - that's the OBDII communication line
You need a PCM ground on OBDII pin 5 (MUST be a PCM/engine ground, not tied to chassis)
You need a power ground on OBDII pin 4 (can be a chassis ground, but preferably engine)
You need +12V on OBDII pin 16 (usually from the cig lighter circuit)
And OBD1 data (Blue 30 pin on PCM) is usually brought to OBDII Pin 9.
That will allow you to scan it with something like AutoTap, assuming you wire it correctly. I've got a benchtop programming harness that works fine set up that way.
And I have done the swap, as has Ellis here (TwoFast4Lv). With LT1Edit for OBDII you can turn off crank sensor code & rear O2's, so those don't matter any more. You can do it with an OBD1 wiring harness.
The reason to do it is for loose torque converters. I had problems with my Yank ST3500. With the OBD1 computer, it couldn't track the VSS signal and would force the transmission in to limp home mode (soft shift to 3rd). The OBDII computer worked just fine.
PCM Blue 7 goes to OBDII Pin 2 - that's the OBDII communication line
You need a PCM ground on OBDII pin 5 (MUST be a PCM/engine ground, not tied to chassis)
You need a power ground on OBDII pin 4 (can be a chassis ground, but preferably engine)
You need +12V on OBDII pin 16 (usually from the cig lighter circuit)
And OBD1 data (Blue 30 pin on PCM) is usually brought to OBDII Pin 9.
That will allow you to scan it with something like AutoTap, assuming you wire it correctly. I've got a benchtop programming harness that works fine set up that way.
And I have done the swap, as has Ellis here (TwoFast4Lv). With LT1Edit for OBDII you can turn off crank sensor code & rear O2's, so those don't matter any more. You can do it with an OBD1 wiring harness.
The reason to do it is for loose torque converters. I had problems with my Yank ST3500. With the OBD1 computer, it couldn't track the VSS signal and would force the transmission in to limp home mode (soft shift to 3rd). The OBDII computer worked just fine.
I was thinking of going to OBD2 my self because theres really only 2 places I can think of that tunes OBD1. No one tunes OBD1 anymore. Theres only one person near me that does OBD1 tunning and thats Brain Herter from PCMforless. All the other performance shop kept telling me they dont do OBD1.
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Oh, if I'm reading your post correctly, you put OBD1 pin "B" at OBDII pin 2? You'll need to move the wire at the PCM connector as well. Field Service Enable (OBD1 Pin B) is at Blue 20. You need to pull that pin out and move it over to Blue 7.
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Verdad Gallardo high stall problem is the reason for switching, no you dont need a differant harness no cranks sensor and stuff is tuned out(hince obd2 swap pcm)
camarohaulic, using shoeboxes diagram
http://shbox.com/1/dlc1.jpg
i used the old "a" ground for both 4 and 5...on the obd2 connector
i have the power on 16 correct too...i know these are correct because the scaner uses these to power up and it does come on it just cannot connect
and ive done the whats in your last post
now to what i dont understand
PCM Blue 7 goes to OBDII Pin 2 - that's the OBDII communication line
And OBD1 data (Blue 30 pin on PCM) is usually brought to OBDII Pin 9.
please clarify!
thanks
camarohaulic, using shoeboxes diagram
http://shbox.com/1/dlc1.jpg
i used the old "a" ground for both 4 and 5...on the obd2 connector
i have the power on 16 correct too...i know these are correct because the scaner uses these to power up and it does come on it just cannot connect
and ive done the whats in your last post
now to what i dont understand
PCM Blue 7 goes to OBDII Pin 2 - that's the OBDII communication line
And OBD1 data (Blue 30 pin on PCM) is usually brought to OBDII Pin 9.
please clarify!
thanks
yea..we tried a few differant things but no luck...i could pay ed wright a whole bunch of money or my tuner was nice enough to pretty much give me this pcm in a trade...so id jsut like to get it installed and working, he says it should work with what ive done..
Well, it's like I said...
OBDII Data (for AutoTap, LT1Edit for OBDII, etc) comes out of Blue 7 on the PCM. That line is not connected to an OBD1 wiring harness. You need to put a pin there, or you'll never be able to talk OBDII to the PCM.
The Field Service Enable line (pin "B" on the OBD1 connector) isn't used for anything that I've ever found. That ties to Blue 20 on the PCM. It's possible to use that wire for your OBDII data... simply move the pin that's in Blue 20 over to Blue 7. You don't need Blue 20 for anything anyway.
There is still some limited OBD1 data coming out of the OBDII PCM. I think the airbag, dash, and ABS systems use it to some extent. That comes out of Blue 30 on the PCM, and goes to OBDII pin 9 on the 95+ F-bodies (1995 had the OBDII style connector, and their OBD1 data wire is on OBDII pin 9 - and the 96-97 LT1 cars have that OBD1 data line hooked up as well, but diagnostics are run through OBDII pin 2 as OBDII data).
I'm pretty sure Ed Wright has a fix for the high stall problem. It does involve a change in the actual code in the PCM.
OBDII Data (for AutoTap, LT1Edit for OBDII, etc) comes out of Blue 7 on the PCM. That line is not connected to an OBD1 wiring harness. You need to put a pin there, or you'll never be able to talk OBDII to the PCM.
The Field Service Enable line (pin "B" on the OBD1 connector) isn't used for anything that I've ever found. That ties to Blue 20 on the PCM. It's possible to use that wire for your OBDII data... simply move the pin that's in Blue 20 over to Blue 7. You don't need Blue 20 for anything anyway.
There is still some limited OBD1 data coming out of the OBDII PCM. I think the airbag, dash, and ABS systems use it to some extent. That comes out of Blue 30 on the PCM, and goes to OBDII pin 9 on the 95+ F-bodies (1995 had the OBDII style connector, and their OBD1 data wire is on OBDII pin 9 - and the 96-97 LT1 cars have that OBD1 data line hooked up as well, but diagnostics are run through OBDII pin 2 as OBDII data).
I'm pretty sure Ed Wright has a fix for the high stall problem. It does involve a change in the actual code in the PCM.
3400...the only run i didnt ahve a high stall problem was the first run ever at the track with this setup, cut a 1.75 and ran 12.50, i backed it up with a 1.60 and ran into issues...
so basically what your sayin is that i should i have it all correct by connecting them like this
went to that junkyard got a obd2 connector and tried wiring it in
B 2.
M 9.
G 8.
a power wire going to 16.
5-a
and i moved the wire inside the blue connector to pin 7 from 20...
so basically what your sayin is that i should i have it all correct by connecting them like this
went to that junkyard got a obd2 connector and tried wiring it in
B 2.
M 9.
G 8.
a power wire going to 16.
5-a
and i moved the wire inside the blue connector to pin 7 from 20...
Joined: Nov 2001
Posts: 10,023
Likes: 6
From: LT1 land...the "409" of the 90s!
Originally Posted by titter
i know a lot of odbi cars running 3400 stalls as well as 3600 stalls ... hell my 3200 is perfectly normal, a little tight but it will loosen up with some more power to it.
Then you are not pushing it nearly hard enough
Yes as Andrew here has said Jimbob65 and I came up with this fix many years ago. I have only ever tested one other fix that worked and it was from Ed Write at Fast chips. I have that one in my car right now,Thanks Ed!
Jim and I could have never done this with out Andrews help so he deserves any business you guys can do with him LOL!
The OBD-II conversion has yet to fail me! If you do not want to do the converion call Ed and buy a tune
Originally Posted by TwoFast4Lv
Then you are not pushing it nearly hard enough
Yes as Andrew here has said Jimbob65 and I came up with this fix many years ago. I have only ever tested one other fix that worked and it was from Ed Write at Fast chips. I have that one in my car right now,Thanks Ed!
Jim and I could have never done this with out Andrews help so he deserves any business you guys can do with him LOL!
The OBD-II conversion has yet to fail me! If you do not want to do the converion call Ed and buy a tune
Yes as Andrew here has said Jimbob65 and I came up with this fix many years ago. I have only ever tested one other fix that worked and it was from Ed Write at Fast chips. I have that one in my car right now,Thanks Ed!
Jim and I could have never done this with out Andrews help so he deserves any business you guys can do with him LOL!
The OBD-II conversion has yet to fail me! If you do not want to do the converion call Ed and buy a tune
Joined: Nov 2001
Posts: 10,023
Likes: 6
From: LT1 land...the "409" of the 90s!
Originally Posted by titter
i dont know ill stay watching a few 9 second cars on 3400 fuddles push it as hard as they need to on a odbi! then again formato tuning the car would explain it all.
Only if they are using a copy of Ed's Tune
BTW how fast is your car?
What I am about to write might be off-topic... or not...? Most OBD2 scanners get power from the same data connector, which is linked in the circuit where the cigarette lighter is. So, if that fuse is blown, it will never link to read codes from the PCM.
Originally Posted by TwoFast4Lv
Only if they are using a copy of Ed's Tune
BTW how fast is your car?
BTW how fast is your car?
also i dont know who ed is, and the car was tuned by jeremy formato, one of the top tuners around this part of the country. he actually tuned the bmr gto to its 9 second pass! here is that article from gmhightech ... http://www.gmhightechperformance.com...s/0506htp_bmr/ he is a late model genuis, and his father was the man from what people tell me back in the 80's ... he does most of the fast tampa area and some south florida area cars!
as far as this swap goes, this was just the first thing i have ever heard about it. i never knew that a stall had issues with the obdi ... thats why i like this site, you always learn something! so the stall causes the computer to go into limp mode? does it throw any codes or a ses light? i want to see what it looks like on a datalog to see if i have any issues. my biggest thing was getting my kickdown corrected.