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4t80E Northstar in 85GT by IXSLR8
Started on: 10-13-2013 10:46 PM
Replies: 82 (2660 views)
Last post by: IXSLR8 on 05-26-2016 01:37 AM
IXSLR8
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Report this Post10-13-2013 10:46 PM Click Here to See the Profile for IXSLR8Send a Private Message to IXSLR8Edit/Delete MessageReply w/QuoteDirect Link to This Post
Configuration: 1985 GT, 1996 Northstar STS engine with stock 4T80E transmission, run by stock Cadillac computer.

We are having 2nd gear starts even when you force it to a manual 1st gear position. It will not start in 1st gear.

Any suggestions?
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Report this Post10-14-2013 12:09 AM Click Here to See the Profile for jb1Send a Private Message to jb1Edit/Delete MessageReply w/QuoteDirect Link to This Post
Mine is 1994 n* so it is OBD1 but I am working on that issue myself , In the factory service manual it stats no communication between the EBTCM and the computer will cause 2nd gear starts , So I have changed uprights and used grand prix hubs to add the WSS and the ebtcm , but have also replaced all ball joints tie rod ends upgraded fr and rear brakes, coilovers etc , so it is taking longer than I would have liked for it to and had to change to 5x115 rear pattern and new wheels. So now I am waiting on new tires to arrive and hopefully can fix the 2nd gear starts.

------------------


87 GT
series 1 3800sc (7.597 @88.53 1.579 60ft)
(series II swap in progress)
85GT Northstar/ 4t80e
86GT 3800 n/a
My Build

[This message has been edited by jb1 (edited 10-14-2013).]

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IXSLR8
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Report this Post10-14-2013 02:22 AM Click Here to See the Profile for IXSLR8Send a Private Message to IXSLR8Edit/Delete MessageReply w/QuoteDirect Link to This Post
I should have added that this is a Wester's adjusted Computer program in that the Rev limiter was removed, EGR deleted, etc.... But its all stock, that is, no aftermarket cams, etc...

I was told By AJ that the computer will defalut to 2nd gear starts if the ABS module, yaw, and steering wheel sensors are not installed with the computer. It can be calibrated out I'm told.

I'd like to know if there is a way to verity this.

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Report this Post10-14-2013 03:09 AM Click Here to See the Profile for jb1Send a Private Message to jb1Edit/Delete MessageReply w/QuoteDirect Link to This Post
I been told the same but no one has ever said that they had a good result from this... yours is different from mine being OBDII, Maybe Darth Fiero will chime in on this.. The majority of the N* swaps are 5sp.... Good luck.

------------------


87 GT
series 1 3800sc (7.597 @88.53 1.579 60ft)
(series II swap in progress)
85GT Northstar/ 4t80e
86GT 3800 n/a
My Build

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IXSLR8
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Report this Post10-14-2013 01:47 PM Click Here to See the Profile for IXSLR8Send a Private Message to IXSLR8Edit/Delete MessageReply w/QuoteDirect Link to This Post
I have an 88GT N* 5 speed, with aftermarket cams, running the altered Shelby LS1 computer and have the stalling issue that is being talked about on this thread: //www.fiero.nl/forum/Forum2/HTML/130519.html

We don't have the stalling issue on the 85GT with the auto 4T80E N* but we have the 2nd gear start issue. We can't get it to start in 1st gear even when using the command 1st gear manual position. Everything else is fine regarding running. We do have a tach issue (not working) which we are trying to figure out as well.

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Report this Post10-14-2013 02:13 PM Click Here to See the Profile for jb1Send a Private Message to jb1Edit/Delete MessageReply w/QuoteDirect Link to This Post
my tach stopped working it was just connection to the back of the cluster was corrode d alittle and loose

------------------


87 GT
series 1 3800sc (7.597 @88.53 1.579 60ft)
(series II swap in progress)
85GT Northstar/ 4t80e
86GT 3800 n/a
My Build

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Will
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Report this Post10-14-2013 03:17 PM Click Here to See the Profile for WillSend a Private Message to WillEdit/Delete MessageReply w/QuoteDirect Link to This Post
Does looping the delivered torque output back to the desired torque input work?

Is that circuit present on the OBDII cars?
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Report this Post10-14-2013 04:04 PM Click Here to See the Profile for jb1Send a Private Message to jb1Edit/Delete MessageReply w/QuoteDirect Link to This Post
from what I have read it is on the obdIi cars, I tried it on mine and it made no change, then had riceburner builed me a pwm generator to run 68hz or so at 90% duty cycle and it caused it to run on 4cy.

------------------


87 GT
series 1 3800sc (7.597 @88.53 1.579 60ft)
(series II swap in progress)
85GT Northstar/ 4t80e
86GT 3800 n/a
My Build

[This message has been edited by jb1 (edited 10-14-2013).]

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IXSLR8
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Report this Post10-15-2013 10:15 PM Click Here to See the Profile for IXSLR8Send a Private Message to IXSLR8Edit/Delete MessageReply w/QuoteDirect Link to This Post
We tried looping the delivered torque output back to the desired torque input and it did not work. It went into 4 cyl. mode and barely ran. Hummmmm.
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IXSLR8
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Report this Post10-18-2013 09:35 AM Click Here to See the Profile for IXSLR8Send a Private Message to IXSLR8Edit/Delete MessageReply w/QuoteDirect Link to This Post
Anyone make a EBTC generator to keep the stock caddy PCM/computer happy?

or

Anyone calibrate the caddy PCM to run without the ABS stuff?
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Report this Post10-22-2013 08:35 PM Click Here to See the Profile for WillSend a Private Message to WillEdit/Delete MessageReply w/QuoteDirect Link to This Post
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Report this Post10-24-2013 01:54 AM Click Here to See the Profile for IXSLR8Send a Private Message to IXSLR8Edit/Delete MessageReply w/QuoteDirect Link to This Post
Lyndon (Westers) did this PCM for us.

He knows of the 2nd gear start issue now because of our situation. I think he will eventually discover that the PCM needs to be recalibrated in order to start in 1st gear when the computer is off-line with the ETBC stuff.
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Report this Post10-24-2013 03:43 AM Click Here to See the Profile for jb1Send a Private Message to jb1Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by IXSLR8:

Lyndon (Westers) did this PCM for us.

He knows of the 2nd gear start issue now because of our situation. I think he will eventually discover that the PCM needs to be recalibrated in order to start in 1st gear when the computer is off-line with the ETBC stuff.

I emailed him a couple times about bypassing all the torque management and abs on mine , he said it was not a problem.. kind of glad I did not spend the cash. the 1st gear starts is my only issue I am aware of.. I used 6000 uprights and grand prix hubs and am currently wiring in the ebtcm, hopefully know if all works in a few weeks...

------------------


87 GT
series 1 3800sc (7.597 @88.53 1.579 60ft)
(series II swap in progress)
85GT Northstar/ 4t80e
86GT 3800 n/a
My Build

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Darth Fiero
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Report this Post10-24-2013 03:02 PM Click Here to See the Profile for Darth FieroClick Here to visit Darth Fiero's HomePageSend a Private Message to Darth FieroEdit/Delete MessageReply w/QuoteDirect Link to This Post
I contacted Wester's myself about acquiring tuning software that can do 96 OBD2 Northstar PCMs. They told me there isn't a definition / template file they could sell me that would work with my existing OBD2 tuning software (C.A.T.S. OBD2 Tuner / Tunercat). Looking at the prices on their website they have listed for complete tuning packages they sell, I can't justify that kind of expense for what I know is only going to amount to just a handful of guys needing custom tunes made. Of course, I'm not even sure if they do sell anything to "the general public" that can tune 96 Northstar PCMs.

Having said that, I already have tuning software that works with the 99 Shelby Series 1 Aurora 4.0 code that runs in the GM 99 LS1 PCM. We know that thru some tuning work, this PCM can run a 4.6L Northstar engine. However, the Shelby tunes were all set up for manual transmissions. And what isn't known is if they can be modified to run automatics.

Earlier this year we discovered the 98-newer 3800 Series 2 SC PCM codes still had logic in them to control 4T60-E and 4L60-E automatics even though these OS's were never used with those other transmissions (they were only used with 4T65-E autos). IT IS POSSIBLE the 99 Shelby OS might have logic in it to control an automatic. Even if it was only set up to run a 4L60-E, that could be modified to control a 4T80-E.

The problem is I need someone to work with on such a project that is willing to do so without any guarantee of success. It would be best if the car could be brought here to my shop; but distance tuning is possible if you can get the scan data we need to do the job.

FYI: There is tuning software available that can tune 2007-newer Cadillac 4.6L Northstar CAN-Bus ECM/TCM combos (these are DBW systems). So if you are thinking of doing a Northstar swap with a 4T80-E automatic, you can get one from a 2007 newer Cadillac and we should be able to custom tune it. NOTE that these systems will NOT work with the Gen1 Northstars (1999-older) due to the different crank sensor reluctor and ignition system.

-ryan

------------------
OVERKILL IS UNDERRATED

Custom GM OBD1 & OBD2 Tuning | Engine Conversions & more | www.gmtuners.com

[This message has been edited by Darth Fiero (edited 10-24-2013).]

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IXSLR8
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Report this Post10-25-2013 02:01 AM Click Here to See the Profile for IXSLR8Send a Private Message to IXSLR8Edit/Delete MessageReply w/QuoteDirect Link to This Post
If your going to use the EBTC module, you will probably need the caddy steering wheel sensor, yaw sensor and the stuff you are already using from the GP.
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Report this Post10-25-2013 02:06 AM Click Here to See the Profile for IXSLR8Send a Private Message to IXSLR8Edit/Delete MessageReply w/QuoteDirect Link to This Post

IXSLR8

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Anyone know what Chris Moore did with his N* conversions relative to the auto trannies?

[This message has been edited by IXSLR8 (edited 01-18-2014).]

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Report this Post10-26-2013 01:54 PM Click Here to See the Profile for jb1Send a Private Message to jb1Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by IXSLR8:

If your going to use the EBTC module, you will probably need the caddy steering wheel sensor, yaw sensor and the stuff you are already using from the GP.


I have not seen anything on the steering sensor on the 94 model. I may have to look into it but mine is setup completely different than what the OBDII is , on the OBDI the EBTCM is mounted in the trunk.

------------------


87 GT
series 1 3800sc (7.597 @88.53 1.579 60ft)
(series II swap in progress)
85GT Northstar/ 4t80e
86GT 3800 n/a
My Build

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IXSLR8
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Report this Post12-30-2013 01:07 AM Click Here to See the Profile for IXSLR8Send a Private Message to IXSLR8Edit/Delete MessageReply w/QuoteDirect Link to This Post
Any updates/success on your OBD1 Northstar and auto?
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Report this Post12-30-2013 03:31 AM Click Here to See the Profile for jb1Send a Private Message to jb1Edit/Delete MessageReply w/QuoteDirect Link to This Post
runs works perfect no 2nd gear starts.. pulls real good off the line 10x better than before
From reading I found that if there is no communication between the ebtcm and the pcm it automatically diverts to 2nd gear starts.. I added wheel speed sensors and all on the rear then wired them with diodes and have no wheel speed sensor codes.. but it does show traction control disabled which is fine for me, I do not want traction control. I wonder if I would still have 1st gear even if I had not added the WSS, I am guessing I would be fine since the TCS is disabled..
I have wondered if anyone has ever tried to wire in just the EBTCM on the OBDII without the brake lines etc, I know the electrical part of the ebtcm is removable from the part where the brake lines attach.... It maybe the same as mine to where is in not actually looking for it to function properly as much as it is just looking for the communication... Hope that makes sense to you.

------------------


87GTseries 1 3800sc (7.597 @88.53 1.579 60ft)
(series II swap in progress)
85GT Northstar/ 4t80e
86GT 3800 n/a
Northstar Rebuild

[This message has been edited by jb1 (edited 12-30-2013).]

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IXSLR8
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Report this Post01-01-2014 09:11 PM Click Here to See the Profile for IXSLR8Send a Private Message to IXSLR8Edit/Delete MessageReply w/QuoteDirect Link to This Post
That's good news after all the work you did!
I'm glad it starts out fine in 1st now and that it accelerates great.

Is there wheel spin in first?

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Report this Post01-01-2014 10:31 PM Click Here to See the Profile for jb1Send a Private Message to jb1Edit/Delete MessageReply w/QuoteDirect Link to This Post
no major wheel spin, I have not really got into it real hard off the line, there are several other things I want to change that I do not like the previous owner did.
I do not think it would just set and white smoke the tires but I have never taken it above 3500 rpm.... so I honestly do not know if there is issue with torque management ( assuming that is what the question is referring to ) or not It is a whole lot better than it was before but not sure it is 100% the car squats a whole lot on hard take offs, do not know much can be done already all new suspension struts and coilovers.

------------------


87GTseries 1 3800sc (7.597 @88.53 1.579 60ft)
(series II swap in progress)
85GT Northstar/ 4t80e
86GT 3800 n/a
Northstar Rebuild

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Report this Post01-02-2014 10:26 AM Click Here to See the Profile for WillSend a Private Message to WillEdit/Delete MessageReply w/QuoteDirect Link to This Post
Great to hear it's running so well!
It's also great to have some solid information on how to get rid of the 2nd gear starts for real.

 
quote
Originally posted by jb1:
the car squats a whole lot on hard take offs, do not know much can be done already all new suspension struts and coilovers.


'84-'87 Fieros just do that. They have pro-squat geometry in the rear that means they really pitch up when you have a lot of power on tap and hammer the throttle.

I have a Northstar/Getrag combo in my '87 GT and have been teased about my car looking like an airplane on its takeoff roll when I floor it in 1st or 2nd.
First in the Getrag is much lower than 1st in the 4T80E, so you may not have it as bad as I do.
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Report this Post01-03-2014 02:11 AM Click Here to See the Profile for bcampbellSend a Private Message to bcampbellEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Will:

Great to hear it's running so well!
It's also great to have some solid information on how to get rid of the 2nd gear starts for real.


'84-'87 Fieros just do that. They have pro-squat geometry in the rear that means they really pitch up when you have a lot of power on tap and hammer the throttle.

I have a Northstar/Getrag combo in my '87 GT and have been teased about my car looking like an airplane on its takeoff roll when I floor it in 1st or 2nd.
First in the Getrag is much lower than 1st in the 4T80E, so you may not have it as bad as I do.


This is so true I have videos of my car doing what looks like wheelies after shifting into 2nd gear and hammering the throttle. That was with stock suspension though.
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Report this Post01-03-2014 02:27 PM Click Here to See the Profile for IXSLR8Send a Private Message to IXSLR8Edit/Delete MessageReply w/QuoteDirect Link to This Post
OK, just to summarize for future swapping:

1) You are using the 1994-1995 OBDI Cadillac computer with the red, white and blue socket connectors: service numbers 16196402 or 16197429;
2) You experienced 2nd gear starts without using the EBTC module and ABS wheel speed sensors;
3) You wired in a EBTC and wheel sensors and your transmission shifts normally now using 1st gear.

Is that right?

Are you using the 95 and later throttle body or the earlier style with the old style IAC setup?
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Report this Post01-03-2014 02:56 PM Click Here to See the Profile for jb1Send a Private Message to jb1Edit/Delete MessageReply w/QuoteDirect Link to This Post
correct.. No I still have the 94 throttle body nothing has been changed. I would l ike to know how to change to a 95 intake but understand egr or pcv us issue


87GTseries 1 3800sc (7.597 @88.53 1.579 60ft)
(series II swap in progress)
85GT Northstar/ 4t80e
86GT 3800 n/a
Northstar Rebuild

[This message has been edited by jb1 (edited 01-03-2014).]

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Report this Post01-06-2014 04:06 PM Click Here to See the Profile for WillSend a Private Message to WillEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by jb1:
I wonder if I would still have 1st gear even if I had not added the WSS,


Unplug them and see how it runs.
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Report this Post01-07-2014 02:01 AM Click Here to See the Profile for IXSLR8Send a Private Message to IXSLR8Edit/Delete MessageReply w/QuoteDirect Link to This Post
Yes unplug the wheel sensors and see if it changes anything. That will help narrow it down.
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Report this Post01-07-2014 04:01 AM Click Here to See the Profile for jb1Send a Private Message to jb1Edit/Delete MessageReply w/QuoteDirect Link to This Post
I had planned on it till the weather dropped to 1 degree. It is suppose to be back in the 50s this weekend I will give it a try then...
I had a pwm module built at I believe 62hz 90% duty cycle, It should tell the computer to run 100% torque, when I tried it the first time without the ebtcm it threw it into limp mode and ran on only 4 cy, I am going to try it again now that I have the ebtcm wired in and working.

------------------


87GTseries 1 3800sc (7.597 @88.53 1.579 60ft)
(series II swap in progress)
85GT Northstar/ 4t80e
86GT 3800 n/a
Northstar Rebuild

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Report this Post01-07-2014 10:41 PM Click Here to See the Profile for IXSLR8Send a Private Message to IXSLR8Edit/Delete MessageReply w/QuoteDirect Link to This Post
Look forward to your results!

It sure is nice to live in, the mild climate of, Oregon right now, huh.

Stay warm.
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Report this Post01-18-2014 03:27 PM Click Here to See the Profile for IXSLR8Send a Private Message to IXSLR8Edit/Delete MessageReply w/QuoteDirect Link to This Post
We picked up a 1996 EBTCM (OBDII unit) and disassembled it from the ABS brake side and pump. We will bare bones wire it up and see if we can get the trans to shift into first without wiring up all the other sensors. It will be interesting to see what codes we get and if it goes into "limp home" mode.
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Report this Post01-18-2014 04:02 PM Click Here to See the Profile for jb1Send a Private Message to jb1Edit/Delete MessageReply w/QuoteDirect Link to This Post
oI only have a few servo codes the traction disabled is still displayed. I Wil unplug wss this week and try it without them.. I have to work today... on mine basically all I hooked up was the wss and desired and delivered torque and the data wires and powrr and ground.

------------------


87GTseries 1 3800sc (7.597 @88.53 1.579 60ft)
(series II swap in progress)
85GT Northstar/ 4t80e
86GT 3800 n/a
Northstar Rebuild

[This message has been edited by jb1 (edited 01-18-2014).]

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Report this Post01-18-2014 09:21 PM Click Here to See the Profile for IXSLR8Send a Private Message to IXSLR8Edit/Delete MessageReply w/QuoteDirect Link to This Post
Hummmm.

We hooked up the module side of the EBCTM unit with these wires:

Switched ignition
Desired torque
Delivered torque
Ground

We didn't hook up the anit-lock indicator lamp (white wire), 2 fat red wires to/from the ABS pump and solenoid valve, traction control disable switch(brown/wh), UART data line (tan), stop/btsi/cruise brake switch input (light blue), or the four WSS sensor wires.

Still have 2nd gear starts.

I guess we will think about those other wires to hook up.

[This message has been edited by IXSLR8 (edited 01-19-2014).]

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Report this Post01-18-2014 09:32 PM Click Here to See the Profile for WillSend a Private Message to WillEdit/Delete MessageReply w/QuoteDirect Link to This Post
It may need the UART to the PCM also.
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Report this Post01-18-2014 09:58 PM Click Here to See the Profile for IXSLR8Send a Private Message to IXSLR8Edit/Delete MessageReply w/QuoteDirect Link to This Post
Dang!...another module to find!
I'll get back to the schematics to learn where this is.
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Report this Post01-19-2014 02:37 AM Click Here to See the Profile for jb1Send a Private Message to jb1Edit/Delete MessageReply w/QuoteDirect Link to This Post
the. uart. " loss of communication to ebtcm" is what causes the 2nd gear start on Obd1
OBD2 will be tan wire pin 29.
I hooked up the 2 red constant 12v , 1 pink switched 12v , brake input , grnd , desired torque ,delivered torque all the wss wire ( really do not believe is needed) and the UART wire.
------------------


87GTseries 1 3800sc (7.597 @88.53 1.579 60ft)
(series II swap in progress)
85GT Northstar/ 4t80e
86GT 3800 n/a
Northstar Rebuild

[This message has been edited by jb1 (edited 01-19-2014).]

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Report this Post01-19-2014 08:13 AM Click Here to See the Profile for WillSend a Private Message to WillEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by IXSLR8:

Dang!...another module to find!
I'll get back to the schematics to learn where this is.


The UART is just a wire from the EBTCM to the PCM. It's the data link that allows all the modules in the car to communicate. It also goes to the diagnostic connector and is how a scan tool talks to the car. Check your wiring diagrams... the Caddy service manual has an entire page dedicated to the entire car's UART wiring.

Edit: As mentioned above, if it has both constant and switched power, you'll need to hook both up.

[This message has been edited by Will (edited 01-19-2014).]

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IXSLR8
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Report this Post01-20-2014 02:34 AM Click Here to See the Profile for IXSLR8Send a Private Message to IXSLR8Edit/Delete MessageReply w/QuoteDirect Link to This Post
We'll try to get those other wires hooked up tomorrow and see what happens.

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Report this Post01-20-2014 08:30 PM Click Here to See the Profile for IXSLR8Send a Private Message to IXSLR8Edit/Delete MessageReply w/QuoteDirect Link to This Post

IXSLR8

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Now I'm confused.

Our OBDII diagrams, in the 1996 GM Service manual (example page 8A-50-4), show no UART wire directly connecting to the PCM. The UART tan wire only connects or loops to several other modules such as: 1) SDM (sensing & diagnostic module), 2) PZM (body control module: translator between the modules), 3) RSS/CVRSS (Road sensing suspension module) and to the 4) EBTCM. The tan wire is also tapped at the EBTCM side and then terminates at the Data Link Connector as an independent pin for scanning.

As I understand it, all the UART modules in the network send their data to the Body Control Module (PZM) and it translates the data/signals for the EBTCM.

jb1, how/where did you hook your UART wire up? Did you use all your other modules as listed above if OBDI uses them?

[This message has been edited by IXSLR8 (edited 01-21-2014).]

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jb1
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Report this Post01-20-2014 08:41 PM Click Here to See the Profile for jb1Send a Private Message to jb1Edit/Delete MessageReply w/QuoteDirect Link to This Post
I only used the ebtcm.. my ebtcm from factory did not go directly to the pcm it was between the rss module and another module I am not using.
From what I have found (not much) It seems you need to look into the PZM (i think ) wiring and also follow the ebtcm wiring , the tan wire pin 29 on the ebtcm is data wire, seems it must have to go to another module (pzm maybe) then it converts it to the class 2 serial data...
look in service manual at the tcs and abs codes, that iis where I found it stated the given code for loss of comm from ebtcm would cause 2nd gear starts. I have a cluster to read my codes, how do you go about reading codes on yours?
It is all going to revolve around the class 2 serial data. if you can use the manual to follow through the diagnostics diagram it should help you figure out where the problem is.
I will try to get access to the diagrams myself and see what i can come up with for you, There are several cadillacs in the local pull-a-part so if getting any modules is a problem for you I will try to help any way I can, I would like
to help figure this problem out for the obdII since it is what most seem to be running..

------------------


87GTseries 1 3800sc (7.597 @88.53 1.579 60ft)
(series II swap in progress)
85GT Northstar/ 4t80e
86GT 3800 n/a
Northstar Rebuild

[This message has been edited by jb1 (edited 01-21-2014).]

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jb1
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Report this Post01-21-2014 04:20 AM Click Here to See the Profile for jb1Send a Private Message to jb1Edit/Delete MessageReply w/QuoteDirect Link to This Post
read this, http://tomboynton.com/GMnetworks.pdf
it is going to take some research but it may need the HVAC module and controls, That is where the dTC codes can be read (same as mine) but it says it sometimes translates uart (5v) to class 2 (7v)... you need to find what translates the uart to serial data... I edited my last post and will try to look into myself for you.. It will probably be trial and error, as mine was but it can be figured out as mine was ,

------------------


87GTseries 1 3800sc (7.597 @88.53 1.579 60ft)
(series II swap in progress)
85GT Northstar/ 4t80e
86GT 3800 n/a
Northstar Rebuild

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