DBW inop. 04 OS

[blindawg]

I swapped an 04 LM7/t56 in my Colorado using the 1mb LS1B PCM, while keeping the Colorado P12 inline in order to keep the use of the gauges and such.

The DBW setup I'm using is the APP, TAC, and TB from the same 04 silvarado the pcm was from. I used all of these componets together with the same tune that I started with when I put a 5.3 in my S10. So I know it all worked. I've also swapped out each of these componets with another one of them respectively and the same issue occurred.

My issue is that the throttle blade won't move with the pedal. It powers up, registers 0%, then goes to the default position and stays there. Won't move after that.

I'm away from my laptop with the tune on it, so I can't upload it yet, just looking to see if anyone has any suggestions as to what my problem is?

Thanks fellas,
Branden

[blindawg]

Here is my current tune file. It's COS3, but other than that it's the same as when the PCM,APP,TAC, and TB were in my S10 and working properly. Would my problem be with the colorado computer being inline with everything?


18251


Thanks,
Branden

[blindawg]

Bumppety bump.

[1FastBrick]

Have you tried Separating the 1MB PCM as a stand alone and making it run that way to confirm everything functions properly?

I suspect it has something to do with how it is wired up but with out me physically seeing how it's set up I couldn't say for sure.

[DURAtotheMAX]

Why is the LS1b PCM piggybacked on the P12??? You do know that the LS1b PCM will communicate properly with the factory Colorado cluster directly on its own....right?

There is absolutely NO reason/need to keep the P12 in there. The GM Class 2 messages to/from the cluster to the ECM are pretty universally understood regardless of vehicle platform. Even a Duramax ECM works properly with a Colorado cluster, for what its worth. Cruise control light, battery light, oil change monitor, PRND321 display, all the gauges etc will work properly. Ditch the P12 and just tie the Class 2 data wire from the LS1b PCM to any Class 2 data wire on the Colorado and you're good to go.

The only thing you'll have to do is something clever with the ignition switch, as the LS1b PCM with the Silverado calibration in it is not programmed to receive a crank-request over the databus (which is how the Colorado is setup)...LS1b is configured to receive crank-request via a discrete pin on the ECM connector.

Only other thing is cruise control; you'll need to make a little interface box that can take the Colorado's resistor-ladder-based cruise control switch and turn it into 3-wire discrete +12v on/off signals that the LS1b PCM needs to see.

Ben

[blindawg]

Have you tried Separating the 1MB PCM as a stand alone and making it run that way to confirm everything functions properly?

I suspect it has something to do with how it is wired up but with out me physically seeing how it's set up I couldn't say for sure.

I need the p12 hooked up in order for ignition to turn on, and crank voltage to happen because of how the Colorado recieves it's crank signal, like Ben said. But I'll try to make a way around that. I just wanted to see if there was a common problem before I went searching through wires. Thanks for the help though! :)


Why is the LS1b PCM piggybacked on the P12??? You do know that the LS1b PCM will communicate properly with the factory Colorado cluster directly on its own....right?

There is absolutely NO reason/need to keep the P12 in there. The GM Class 2 messages to/from the cluster to the ECM are pretty universally understood regardless of vehicle platform. Even a Duramax ECM works properly with a Colorado cluster, for what its worth. Cruise control light, battery light, oil change monitor, PRND321 display, all the gauges etc will work properly. Ditch the P12 and just tie the Class 2 data wire from the LS1b PCM to any Class 2 data wire on the Colorado and you're good to go.

The only thing you'll have to do is something clever with the ignition switch, as the LS1b PCM with the Silverado calibration in it is not programmed to receive a crank-request over the databus (which is how the Colorado is setup)...LS1b is configured to receive crank-request via a discrete pin on the ECM connector.

Only other thing is cruise control; you'll need to make a little interface box that can take the Colorado's resistor-ladder-based cruise control switch and turn it into 3-wire discrete +12v on/off signals that the LS1b PCM needs to see.

Ben

This information is based on my buddy's colorado that has the same setup, except DBC. I didn't wire his up or tune it, so I can't say exactly how his Is done, but his gas gauge didn't work Until we hooked it up through the p12, and the speedo has never worked through either pcm. And I am almost sure of the fact that the ls1b doesn't send serial data out for the speedo, but it sends out a VSS wire, that goes to the cluster, which then turns it into serial data. That's just how I interpreted the wiring diagrams anyways. I would love to be wrong about that though. Lol.

The other reason I'm piggybacking the p12 is because of te ignition switch problem. Sure, I could buy the $125 CP ignitions switch, but that's no fun. Lol.

I have tried pulling the serial data wires out of the p12 and just hooking them together, so it would get the p12 off the databuss, but this did not help anything.

Thanks for the help guys! I appreciate it!
Branden

[DURAtotheMAX]

This information is based on my buddy's colorado that has the same setup, except DBC. I didn't wire his up or tune it, so I can't say exactly how his Is done, but his gas gauge didn't work Until we hooked it up through the p12, and the speedo has never worked through either pcm.

Drive by cable, so Im assuming a 2002 or older operating system...try a 2003-2005 operating system on the 1mb PCM.



And I am almost sure of the fact that the ls1b doesn't send serial data out for the speedo

True, but neither does an 01-07 Duramax, and when I used an 04 Duramax calibration in a Colorado/Dmax swap, I was able to get the cluster working properly.... Both tach and speedo both go over discrete wires on the 2007 and older GMT-800 full size trucks/SUV's. But the PCM still broadcasts tach and speedo info over the databus (like for scan tool usage)....and the Colorado cluster picks that up over the databus and displays it, just like a scan tool plugged into the OBD port.

Plus, ALL 03+ Express vans use serial data for speedo. The 2003-2007 Express vans use the same LS1b PCM as the pickup trucks/SUV's, but they do not have a discrete speedo signal wire. Why GM did this on the Colorados and Express vans, but not the pre-2008 trucks/SUV's I dont know.

Ben

[blindawg]

Drive by cable, so Im assuming a 2002 or older operating system...try a 2003-2005 operating system on the 1mb PCM.




True, but neither does an 01-07 Duramax, and when I used an 04 Duramax calibration in a Colorado/Dmax swap, I was able to get the cluster working properly.... Both tach and speedo both go over discrete wires on the 2007 and older GMT-800 full size trucks/SUV's. But the PCM still broadcasts tach and speedo info over the databus (like for scan tool usage)....and the Colorado cluster picks that up over the databus and displays it, just like a scan tool plugged into the OBD port.

Plus, ALL 03+ Express vans use serial data for speedo. The 2003-2007 Express vans use the same LS1b PCM as the pickup trucks/SUV's, but they do not have a discrete speedo signal wire. Why GM did this on the Colorados and Express vans, but not the pre-2008 trucks/SUV's I dont know.

Ben

Yes on the older OS. I should mention he used a 512kb ls1b on his. Just for reference Ig. I'm using an 04 OS on mine. We're you saying use an 03-05 on my buddy's?

And oh. This does make sense. At least as to why it SHOUDL work, but not to why it doesn't. But like I said, he had someone else wire it up and tune it so idk what all would be his problem. But this information will come in extremely useful and I'll probably ditch the p12 knowing this, so thank you for clarifying that for me. :) I'll work on it and get back with any results! I may bug you about how to the the gauges working. :)

Thanks again,
Branden

[DURAtotheMAX]

Yes on the older OS. I should mention he used a 512kb ls1b on his. Just for reference Ig. I'm using an 04 OS on mine. We're you saying use an 03-05 on my buddy's?

Well you're going to need to swap your buddys truck to a 1mb PCM first......you cant load an 03+ calibration into a 512k PCM.


But like I said, he had someone else wire it up and tune it so idk what all would be his problem

A lot of times, people "assume" things wont work without even trying them, especially with computer/electronics/wiring related stuff. :grin:

[blindawg]

Right, I was just making sure we we on the same page. Lol.

Believe me, I looked at it every way I could to try to figure out a way to make it work. :) obviously your knowlage exceeds mine on this and that's good news for me! Lol.

Thanks for the help, I should make some progress on mine tomorrow.
Branden

[blindawg]

Well fellas, good news is that the speedo works. I hadn't had a chance to even move it yet until this weekend.

Bad news is, the pedal still doesn't work with the p12 completely Unpluged. Anyone have anymore suggestions?

Thanks,
Branden

[joecar]

Hey Branden, good job on the speedo :cheers: you've come a long way :cheers:

[blindawg]

Thanks joecar! Only thing is, I didn't do anything to it. Lol. It must just be the 03+ OS that do it.

Still am clueless about the dbw though. :/

[DURAtotheMAX]

You are using a pickup truck pedal right? The colorado pedal is different.

[blindawg]

Correct.

[blindawg]

Alright fella's, I have isolated the LS1B from the P12 and colorado BCM, along with unplugging the abs module just because. No luck with the throttle. :( I'm all out of ideas for the time being. I'm close to going DBC just to get everything else finished and then come back to this.

Branden

[DURAtotheMAX]

At this point I HIGHLY doubt it has anything to do with the fact that its been swapped into a Colorado or anything like that...you've traced ALL the wiring from the pedal to the TAC module? Tried a different TAC module? Tried a different pedal? Tried a different ECM???

[blindawg]

I don't even have the TAC or the pedal installed in the truck yet. Just sitting in the engine bay. So yes, all wiring is good, I've tried a Different TAC, Pedal, and TB. No to a different ECM. And now that I'm thinking about this..... I might have messed with the tune when I was going to use this pcm in my blazer, and forgot about me doing so. If that's what it is I'm going to feel real dumb. If it isnt in the tune, then I guess my only thing left is to try another ECM?

Thanks for the help,
Branden

[blindawg]

Well, I might have found the problem. My blazer was DBC, so I said "NO" on the "Electronic Throttle" option in the vehicle platform table. I'm assuming this would cause it to be unresponsive? If so, Facepalm hardcore.

Thanks for the help fellas, I'll let ya know if this fixes it.
Branden

[turbo_bu]

Branden,

Thanks for sharing your story on getting this swap to work. I do have one question for you regarding the Electronic Throttle option that you selected. I have "heard" that you can convert a DBW to a DBC tune by changing this option and then adjusting the other necessary tables in EFI Live. From what you have described, you actually did it with a 1 MB LS1B OS. I have wanted to try this b/c it gives more options to those who are looking at doing flex fuel OS with COS. Please let us know if that is what ends up fixing your issue (read another way, you proved that you could take a DBW tune and make it stop looking for it ..... and it didn't brick the PCM).

[blindawg]

http://www.lt1swap.com/cable_conversion.htm

I didn't end up using it as DBC, but that link will tell you what you need to know in order to do it!

Changing it back to "yes" in the platform table fixed my problem. Sigh.... Glad it was simple, but wish it didn't take 2 weeks to figure out. :-P

Thanks everyone for the help, especially Ben for asking the rift question to make me remember I did that!
Branden

[joecar]

( the stuff that is the most difficult to figure out is what etches permanent paths inside a person's brain... you can forget your name and address, but you will always remember how you got the PCM to play with the throttle )

[blindawg]

Well said. Very well said. Lol. On to the next etching of the brain!