2009 Gm Retractable Running Boards On 2004 Avalanche

Fordtech · April 10, 2009

Hello, Im adding a used set of Retractable Running boards from a 2009 GM suv and adding them onto my 2004 Avalanche....

Ive had to modify the mounting to fit my truck but now im stuck with the wiring issues....

I have both motors wired up to the relay module that comes with the running boards which is found on the drivers center of the vehicle.

My issue that im running into is the GMLAN system (CAN) there are 2 wires left...a Solid dark green which is the GMLAN wire (Computer signal wire) and a Tan with White stripe (Disable signal) wire....

Now im assuming that the Disable wire which routes itself throught the multifunction switch to the I/P is for disabling the running boards through the Electronic Message center....now this is something i do not want disabled as i want them on at all times so i guess this wire should just be left alone? also what kind of signal wire is the GMLAN wire putting out....according to the Wiring schematics it runs into the PCM. Obviously the pcm is gonna see a few signals, Door switch, Interior lights etc, Door unlock/lock......Now in theory should i not just be able to apply 12v to this wire are watch it retract? but how do i get it to retract at the same time??? What is my next step to get a step???

Fordtech · April 10, 2009

bump

TexasAl · April 10, 2009

I am not familiar with this setup, but in theory, all you need is a signal to the relay when to turn on (running boards come down) and when to retract (running boards go up). I am thinking that wire from the computer makes them come down. All you have to do is find a power source (signal) that is activated when you hit your remote or when you open your door. It doesn't have to be high power since it is connected to a relay. I am thinking that the dome light would be good to activate the steps to come down. What do you mean when you say "but how do i get it to retract at the same time??? " . Let us know.

Fordtech · April 11, 2009

I am not familiar with this setup, but in theory, all you need is a signal to the relay when to turn on (running boards come down) and when to retract (running boards go up). I am thinking that wire from the computer makes them come down. All you have to do is find a power source (signal) that is activated when you hit your remote or when you open your door. It doesn't have to be high power since it is connected to a relay. I am thinking that the dome light would be good to activate the steps to come down. What do you mean when you say "but how do i get it to retract at the same time??? " . Let us know.

well i have a constant power and ground wire to power the relay module... then the pcm signal wire and a disable switch...now since the pcm signal wire is what commands the relay module to open or close the running boards how is the module gonna know what command to send the running boards to do??? lets say its hooked up to the dome light...light turns on and send a signal to the module to extend the boards and the light turns off when the door closes so then how is the module gonna know that it has to retract now??? i tried applying 12v with a battery charger and nothing would happen....

brims · April 11, 2009

GMLAN is just that, a network. It sends and receives binary data, applying 12V to that wire might burn up the controller. It's possible the truck will need to be programmed to work with the running boards. The signals that the BCM gets from those other modules is a communication signal, not just 12V or 0V, it is a network.

Fordtech · April 11, 2009

GMLAN is just that, a network. It sends and receives binary data, applying 12V to that wire might burn up the controller. It's possible the truck will need to be programmed to work with the running boards. The signals that the BCM gets from those other modules is a communication signal, not just 12V or 0V, it is a network.

so how do you think i would be able to trick the module? or do you think i would have to bypass it? still...the motors have sensors to know when you time out. and would i have to use a relay per motor or you think i can use one for both?

brims · April 11, 2009

If the motors have some sort of sensor to know when they are extended or retracted to shut off the motors and they aren't connected using the module, you may be able to cut out the module. I don't know anything about them so I can't tell you if you can or cannot do so. It may be possible but I wouldn't know how. I believe aftermarket retractable running boards have such equipment, but I may be wrong, some may hook into the GMLAN to get the signal that the door is open.

I would do some research into some aftermarket running boards and find out if any of them are stand alone and see if you can get their control units or get a wiring diagram to be able to build your own. Will take some work, but it probably can be done. It's possible someone has a kit to allow you to use these running boards on your truck.

Actually, thinking about it, you may not have to have anything reprogrammed. The controller for these running boards may just "snag" the door open signal off the GMLAN.

I'm just throwing out ideas. I don't know much about these. Hope I could at least get some ideas in your head.

TexasAl · April 11, 2009

I am not familiar with this setup, but in theory, all you need is a signal to the relay when to turn on (running boards come down) and when to retract (running boards go up). I am thinking that wire from the computer makes them come down. All you have to do is find a power source (signal) that is activated when you hit your remote or when you open your door. It doesn't have to be high power since it is connected to a relay. I am thinking that the dome light would be good to activate the steps to come down. What do you mean when you say "but how do i get it to retract at the same time??? " . Let us know.

well i have a constant power and ground wire to power the relay module... then the pcm signal wire and a disable switch...now since the pcm signal wire is what commands the relay module to open or close the running boards how is the module gonna know what command to send the running boards to do??? lets say its hooked up to the dome light...light turns on and send a signal to the module to extend the boards and the light turns off when the door closes so then how is the module gonna know that it has to retract now??? i tried applying 12v with a battery charger and nothing would happen....

OK, you said you have the 12V Power & Ground connected to the relay. Now connect a power wire at the fuse box, and apply it to the "signal" connector on the relay. That should activate the motors. You can go to autozone or most auto parts stores, and get a "fuse tap" that connects into an existing fuse connector, and allow you to "tap" into that fuse and add the accessory you want to add. This adapter looks like a wire coming out of a plastic fuse.

If you are lucky, the motors will lower when you apply power, and retract when you terminate the power. If you used a battery charger, you are not on the same circuit and it is not a complete circuit, so the "signal" will not work. You need to get the power from the truck. It does not have to be a 12 volt power either. Almost any signal should work coming from the truck. Let us know if it works.

Al

Ranger · April 11, 2009

One thing to consider is the data systems on a 04 and an 09 are completely different...What I would do is find a contact switch and install it in the jamb, so when you open a door it will lower the steps. This is how the AMP research steps do it, and they looked pretty good on my uncle's NBS Super Duty F-450. Actually I couldn't even tell he had side steps, I was wondering how my Aunt was gonna climb up in that tall mofo, then I open the door and down comes a step haha.

TexasAl · April 12, 2009

Update?

Fordtech · April 12, 2009

Update?

still trying to figure out how to get the systems to work together...for all I know i fried the module applying 12v to the gmlan signal wire....that really seems to be the only wire i have left....the other wire is the disable wire which is normally open untill disabled then its grounded so that one i dont have to worry about....the green gmlan signal wire must pickup the signal for door switch open/closed, now i dont really see GM changing the binary codes for these commands just because it is a new system...but thats a wild guestimation.....the only thing that module is really doing is timing out the signal after so many ms... I found how they do it with the AMP Power Step and they take the 4 door pin wires and using diodes in a splitter connector use the left and right door pin signals to open and close the running boards....im just a lil nervous that if i used just those wires on direct to the motor that it wont time out and burn up the motor...

TexasAl · April 12, 2009

Update?

still trying to figure out how to get the systems to work together...for all I know i fried the module applying 12v to the gmlan signal wire....that really seems to be the only wire i have left....the other wire is the disable wire which is normally open untill disabled then its grounded so that one i dont have to worry about....the green gmlan signal wire must pickup the signal for door switch open/closed, now i dont really see GM changing the binary codes for these commands just because it is a new system...but thats a wild guestimation.....the only thing that module is really doing is timing out the signal after so many ms... I found how they do it with the AMP Power Step and they take the 4 door pin wires and using diodes in a splitter connector use the left and right door pin signals to open and close the running boards....im just a lil nervous that if i used just those wires on direct to the motor that it wont time out and burn up the motor...

Did your steps come with directions on how to install them? If so, would you mind scanning them? Also, if possible, take a picture of the wires, module(s) and motors that are on the steps. If you can post those here, I'm sure we can figure this out.

Al

chevyinside · April 12, 2009

Update?

still trying to figure out how to get the systems to work together...for all I know i fried the module applying 12v to the gmlan signal wire....that really seems to be the only wire i have left....the other wire is the disable wire which is normally open untill disabled then its grounded so that one i dont have to worry about....the green gmlan signal wire must pickup the signal for door switch open/closed, now i dont really see GM changing the binary codes for these commands just because it is a new system...but thats a wild guestimation.....the only thing that module is really doing is timing out the signal after so many ms... I found how they do it with the AMP Power Step and they take the 4 door pin wires and using diodes in a splitter connector use the left and right door pin signals to open and close the running boards....im just a lil nervous that if i used just those wires on direct to the motor that it wont time out and burn up the motor...

Did your steps come with directions on how to install them? If so, would you mind scanning them? Also, if possible, take a picture of the wires, module(s) and motors that are on the steps. If you can post those here, I'm sure we can figure this out.

Al

remember the gm lan network is very simmalir to the ford ms_can network , it's a meduim speed bussed network ,that is by directional .It's not just thowing 12volt on that line. in fact it's probley only throwing 5 or less . If you apply strainght 12 to it youll frie the module for sure . why dont you just eliminate the module ad make your own system with wires and relays . it will work out for you better that wasy.

TexasAl · April 13, 2009

Update?

still trying to figure out how to get the systems to work together...for all I know i fried the module applying 12v to the gmlan signal wire....that really seems to be the only wire i have left....the other wire is the disable wire which is normally open untill disabled then its grounded so that one i dont have to worry about....the green gmlan signal wire must pickup the signal for door switch open/closed, now i dont really see GM changing the binary codes for these commands just because it is a new system...but thats a wild guestimation.....the only thing that module is really doing is timing out the signal after so many ms... I found how they do it with the AMP Power Step and they take the 4 door pin wires and using diodes in a splitter connector use the left and right door pin signals to open and close the running boards....im just a lil nervous that if i used just those wires on direct to the motor that it wont time out and burn up the motor...

Did your steps come with directions on how to install them? If so, would you mind scanning them? Also, if possible, take a picture of the wires, module(s) and motors that are on the steps. If you can post those here, I'm sure we can figure this out.

Al

remember the gm lan network is very simmalir to the ford ms_can network , it's a meduim speed bussed network ,that is by directional .It's not just thowing 12volt on that line. in fact it's probley only throwing 5 or less . If you apply strainght 12 to it youll frie the module for sure . why dont you just eliminate the module ad make your own system with wires and relays . it will work out for you better that wasy.

That's what I'm thinking. I just wanted to see the setup to get a better idea.

brims · April 13, 2009

As Ranger said, they are different data systems, the new ones are CAN, so the way they communicate is completely different, the signal itself may be the same but the way it's "packaged" is probably different.

Anyways, eliminating the module would probably be the easiest way.