I ran some wires to the shifter but didn’t have to change any of the interior wiring harness.

 

Hey, thanks for the reply Spaz, mines an m56, do you remember which extra wires you ran to the shifter?
I have the tuned 411 ecm coming from a well known tuner this week..ill repin the existing 98 harness with new red/blue connectors I got from ebay... and then see what needs to be done from there..really I just want to get this new motor running and driveable then work on any gauges that arent reading or other minor issues, as long as its safely driveable I can deal with the other stuff over time..my thing was i dont want to just plug the three connectors in inside the car and mess something up..
I even thought of going old school for the gauges and using a nice mix of matching auto meter ones and making a dash bezel where the speedo is now to hold them all, if any issues arise in the interior wiring.

 

Okay, heres a simple answer to a question Ive spent hours verifying.

Will the 99 and up PCM work with the existing 98 BCM thats in the car?

Yes..except for 2 pins which can be left unused if desired.

C3 is the large 32 pin plug, it is physically the same for all years 98-2001

The differences are..

All but C15 and C16 are the same, and both can be worked around or deleted without affecting the way the car BCM works otherwise

Pin C15 on the 98 harness is a low coolant wire
Pin C15 on the 99 and up is not used

Pin C16 on the 98 harness is not used
Pin C16 on the 99 and up BCM is for an Alarm Armed signal

There may be other pins used differently on the actual PCM swaps from 98 to 99 and up, but this question was specifically for the interior plugs (Body Control Module) and their pinout differences.

The other two plugs, C1 and C2 are the same except for they used different names for the same pin usage on different years.

So, if you have a 1998 and are looking to upgrade to a 99 and up 411 PCM, you do not need to do anything except address your needs for a low coolant sensor, and whether you have a need for the full functionality of the factory alarm.

Repin those two (C15 and C16) as needed or leave them blank, then (most important of all take a deep breath) and repin the red and blue PCM plugs to the correct pinout of the 411 PCM using the pinout comparison found above. All this info is from what I have been able to dig up here on the LS1 tech forum, and one more reason why I come here daily to check out the latest ideas and most proven mods and upgrades for my own 98 T/A.

Please anyone who notes if anything is wrong here and let me know otherwise so I can edit this, but for now this is how I will be doing my 98 PCM to tuned 411 PCM Ill be installing soon.



Cheers
Dave

 

I realize this is an older post, but do you still have the information on record to swap the 2002 PCM into a 98?

 

Hey Christopher.
Heres the pdf with all the pin numbers and colors and instructions on the swap...

http://www.mrk-motorsports.com/wp-co...o-1999-PCM.pdf

Buy a couple of used pcm connectors on ebay and set them next to the old ones, and swap the wires one at a time.

Takes a couple hours, and its done except for mounting the pcm which is up to you since theres no set in stone way to do it.

Theres also a swap thread here on this forum that gives yo the wire colors with their actual uses, if your not sure if a wire is necessary or not, just to be sure since auto tranny will hve a few extras the M6 wont have.

Everything else is left as is, the only thing youll be changing are the wire locations in the PCM connectors and the PCM itself.

I did this a couple months ago, and drive my 98 TA daily, without one issue so far...

Good luck
Dave

 

hey man i have a 98 ta i just swapped in a 5.3, 2000 harness and pcm gauges are going crazy. I need help with The re-pin. Any info would be greatly appreciated.

 

You will want to think about changing all the sensors to 99 and up style, to work with the harness, the 411 PCM will work with the repin method and the original 98 harness and a fuel segment swap, but I think the 2000 harness might not like the 98 sensors..and also you may need to consider the BCM(body control module inside the right kick panel) is not seeing the right signals from the 411 PCM either due to the 2000 harness and 98 BCM not getting along.

If you used the 99 and up sensors, then you may want to look for a bad ground somewhere..on the engine probably or one of the black ground in the PCM connectors may have been loose.

Theres two or three at the back of the drivers head, and two straps from engine to body...one lower left one lower right...

Another thing is when you swap the 98 PCM to the 411 PCM, the tuner needs to do a "fuel segment swap" to work with the 98 fuel gauge.

If you have the 98 sensors and harness still, you could probably just put it back in and everything should work properly except for the fuel gauge if you havent had the fuel segment swap done.
Good luck!
Dave

 

I see this is an older post but I am having some issues with my swap. I bought the car with a repined harness so it’s hard for me to track down exactilly what’s going on. So I am getting a low coolant sensor code along with a tp sensor code. Can this be something I am forgetting to hook up? Please someone help me in the right direction

 

Are you using a 411 pcm with a 98 harness? I would go through that chart and check every wire color, and always consider that moisture might have gotten into the connector or you may have a bad coolant sensor....also the sensors on a 99 and up harness are wired differently I think theres one with a 2 wire plug and one with a three wire plug...I cant remember which my 98 original harness is...as for the TP sensor, youre using the DBW in place of the mechanical TB of the 98 might not be working because the pcm programmed for a 98 harness wont work with the DBW. if youre using a 98 harness my guess is there are wires missing that either need to be there or need to be added and ran to the TB...Ill check mine tomorrow to see if the coolant is 2 or 3 wire at any rate if you are using a 411 and a 98 harness the tuner will have to make sure the pcm knows its connected to a 98 harness and sensors instead of the 99 and up that its used to seeing...and dont rule out calling or emailing Frost...he might be able to steer you better...or even reprogram your 411 properly to work with that 98 harness...good luck!

 

Putting this here to have some continuity with the thread...maybe someone can add in some advice here too..cheers!

Dreamls needs a bit of sensor help:

If I remember right there were three wires I didnt use..all for the A4 trans (down to the shifter)..mines a t56..you can cross reference the colors with the chart, the black/white may be a ground. The most likely culprit if the car did run well before, is to assume something is not connected, like a pin or ground, but you might also have bad sensors..Ive had to replace all of those on mine, the map and cam sensor more than once, they just dont like being removed and reinstalled theyre so cheap and flimsy...I hate to say it but it may be worth the coin to find a local shop who can plug it in with a diagnostic machine, and save the time and effort of throwing new sensors at it.

You may have a bad connection at the pcm on one or more of the pins, since when repinned they can be easy to yank one and have it still be in the connector but not making full contact with the pcm side. Also when a repin is done, some pin holes are left open and moisture can get in..check the connectors for corrosion and continuity between the end of the pin and the back on the outside of the connector.
The Tp sensor isnt adjustable, so it cant be installed off, so check to make sure it has all the correct reference voltages and a ground with a multimeter, and as for the coolant sensor, those can read wonky if theyre going bad, check the reference voltages on that at the sensor as well..and the map too. All these are typically easy to find a thread on in the PCM and diagnostics section of this forum.

Heres the link: https://ls1tech.com/forums/pcm-diagnostics-tuning-7/

Sometimes the MAP sensor will not plug in all the way and be loose or intermittent..make sure its connector is firmly seated and remember the map sensor must be scaled in the pcm to match the sensor, so if youve got a sensor from another car, that might look identical, sometimes they wont work properly. Also make sure the MAP connection to the intake isnt so loose it creates a vacuum leak.

And definitely make sure your intake is torqued to specs, and doesnt have any leaks around the gaskets, which could let dripping cowl water in and cause a hydrolock..something very common with f body ls cars.

Easiest way to eliminate possibilities, is to replace all three sensors, since youre doing the project its always good to use new ones anyways, but my first place to look would be checking the voltage and grounds against the charts for the sensors, and checking the pcm connections for continuity across the connectors and corrosion or moisture intrusion.

Ill keep an eye out here..all the best luck!
Dave

 

Well, I figured out my problem. For the MAP and Cam sensor, these plugs are identical and I had them plugged in wrong. I had to look at the wiring schematic to figure that out. For the engine coolant temp, i was using a 2001 sensor an i guess the harness didn't like it. Plugged in a 98 sensor. and its reading in HPtuners now. I am waiting on a Fbody specific MAF, the truck sensor i am using is not reading or scaling wrong. I am hoping this solves my issues. Thanks for the help Dave!

 

Hey I just did this repin on my 98 Camaro 5.7 ss and now I'm not able to do the relearn procedure as suggested because all the lights on the cluster is illuminated when only the security lights is supposed to be active. However, in frustration I went on to try to crank the car, which did start, but only after I pump the gas pedal. And even then, it only stays running if I keep my foot on the gas pedal. And moreover, as I continue to give it gas to keep it running, it starts to overheat because my cooling fans are not activating. What's going on? And does the three or four wires deleted on the 0411 repin have anything to do with the car now running really ruff since this repin change?

 

First thing is, is your LS1 fully stock, with all factory sensors intact and is your BCM fully stock?

Number two would be that the pcm youre using needs to be bench programmed for your needs out of the car, it will not work if you yank it from a 2000 car and just put it in.

A possible fix for this at this point is to replace all the sensors with 99 and up and get a 99 and up wiring harness.

Or send the PCM off to be bench programmed to work with your 98 BCM and sensors

Number three, make sure all grounds are solid, if any of the grounds to the pcm arent right weird stuff will happen.

On mine I ordered a 411 from a well known tuner and he shipped it to me all setup-
5.3 cammed -no cats- two instead of four O2 sensors-headers and bigger injectors.

It was also ready to interact with the 98 BCM.

Once it is in the car you can connect to the pcm and tune it further with no problem.
The extra wires were for me auto trans stuff and I have an M6.

If that doesn't fix it:

I would say the weird dashlight scenario may be from some wire or wires being in the wrong place.
Its so easy to get one wrong, use a bright led light to see the colors clearly.

Did you reuse your 98 harness?
I did, I cleaned it up rewrapped and used all new ac delco 98 sensors.

If you bought a new harness that could create an issue Ive seen a few that didnt work out of the box the last couple years.

I am guessing you also may have unplugged your BCM, make sure its connected tightly again and grounds are tight.

We did a friends car last year this way and he got a couple wires off and the gauges didnt work and it wouldnt start.
He also ordered a pre-programmed pcm, and as soon as he fixed the two wires it fired up and we finished tuning it.

Wishing you good luck and feel free to share your results here so everyone can see, cheers!
Dave