What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

My 5.3 swap thread!

I believe this is what he used. Regardless, this is what most swaps are using.
ap_644110.jpg
-6 AN Male to 5/16" SAE Quick-Disconnect Female with threaded retaining cap
P/N 644110 or 644113
and
-6 AN Male to 3/8" SAE Quick-Disconnect Female with threaded retaining cap
P/N 644120 or 644123




ap_644110.jpg
 
Err, shoulda paid more attention to your drawing. VSS should = Speedometer, sorry! Your PCM replaces the DRAC module when you do the swap. You'll hook the green and purple wires from the stock VSS on the transfer case up to pins 20 and 21 on the red connector on a 02 PCM. The PCM then generates the output signal for the speedometer. The pull up resistor just changes the signal to work with your stock speedometer.
 
IMAG0324.jpg


Like this? Obviously my pen changed colors too! LOL
 
yup, that's better!

By the way, the speedometer is pin 50 of the red connector in the drive by cable trucks.
 
I got this about the speedo and temp sensor,

heres the oversimplified solution to all problems in the ...
get a 88-91 suburban inst. cluster with elec. speedometer. you cannot just snatch the speedo out becuase the PC board is different, and the housings are different. i myself have 2 and both are for sale 65+shipping. a very very simple repining of the factory inst. cluster harness and your all set. connect the VSS signal from the computer to the #18 pin of the connector, and call it done.
as far as the temp, autometer makes a probeless water temp sender, and adapter for the ls motors. it reads a tad incorrectly (15*) but whatever, im thinking of just taking the needle off, and resetting it by hand, or even trying to play with resistors.
autometer 2277 is the adapter
autometer 2259 is the probless. you dont want probe syle becuase it doesnt fit in the adapter, you would have to bore it out (becuase we did that to my friends swap), plus automtere asured me it reads the same.
anyway thats the solution to your problems and they are all cheap to get/do
Click to expand...

From here,

http://www.ls1truck.com/forums/lsx-truck-conversions/14326-can-anyone-help-my-speedometer.html
 
TBI computer wires that i might need/want to retain.

From here,

http://www.binderplanet.com/forums/showthread.php?t=45293

A1- grn/wht- this wire is used to energize the fuel pump relay.
A5- brn/wht- SES(service eng soon) light. This is a ground to turn on the light.
A6- pnk/blk- switched 12v from the ignition relay.
A10- brn- VSS speed sensor signal to the ECM (optional)
A12- blk/wht- System ground. Can be tied with D1. Goes to engine ground.
B1- orn- 12v fused from battery. I use an inline fuse on this. It also ties into C16.
B2- tan/wht- Fuel pump signal from the relay. This one ties into several places, the fuel pump, the relay, and the ecm. When the relay is on it sends 12v thru this wire to turn on the fuel pump, at the same time it tells the ECM the fuel pump is on.
B8- dk grn- AC signal. This tells the ECM that the AC is turned on. This can be used to set the idle speed higher when you turn the AC on. I use it to increase the idle when using the compressor for on board air. Same thing!! Just tie it to the wire going to the AC clutch.
B10-orn/blk- Park/Neutral sw. This is optional but I have hooked it into the park sw on the tranny. It tells the ECM when you are in Pk or N. It can be used to give a slight adjustment to idle speed when switching from park to drive and back.
C9- ppl/wht- starter crank signal. Goes to the small terminal of the starter. The stock scout wire is white that goes there. Tells the ECM you are trying to start the engine.
C16- orn- fused 12v tied to B1
Click to expand...
 
I have been very much confusing myself on the darn speedo/ecm speed signal issue! More on that later. Try like heck to get a clear understanding of what i need to be doing. So i made up this little better drawing of how to wire the speedo.

VSSwiring.jpg


So this is right for once i feed the ECM a VSS signal right? Now, How exactly do i get the LM7 ECM to hear the VSS on my np241?
 
A little something i put together off a 7747 pin diagram for the VSS/drac circuit. I think it will help me later.

vssdiagram.jpg



Sith some possibly helpfull info.

I've been running around with no cruise for the longest time so I thought I'd get around to fixing it. The answer was very simple with help from GasGuzzler. Access the DRAC unit and cut the light blue wire with black stripe. Cut the red wire with white stripe. Take a butt connector and stick the two wires in one end and crimp. Take the speedometer signal wire from the PCM and crimp it to the other end. Job done.

BTW, the cruise control cable I used is from a 1998 C1500 with a Vortech V8.
Click to expand...

And also more info on the drac,

http://www.tbichips.com/drac/
 
You do not need to use a DRAC, at all. Throw it out. Burn it. Stomp on it. Let the fat lady sing on the issue already!

Your 5.3L PCM IS the DRAC. You take the green wire and purple wire from the VSS on your transfer case and plug it directly into your new 5.3L PCM. The sensor in your t-case right now is literally the exact same sensor as you'd find in the donor Tahoe's transfer case.

The PCM then takes that signal from the t-case sensor and does an internal calculation to convert it into a 4000 pluse per mile signal that your speedometer uses. The PCM then sends that signal on the green / white wire directly to the speedometer. However, since your speedometer cannot "see" the ground pulse signal, you must use a pull up resistor to convert the pulsed ground signal to a 12V square wave signal that the speedometer can see.

Done, nothing more to it! No need for some crazy insane hybrid thing you've got going on in your brain ;)

If you need to use the stock cruise control module to run the drive by wire throttle body, simply splice it into the same signal that is going to your speedometer and call it done too. Both the cruise and speedometer wires both run into your DRAC right now. Pull them out and throw the rest in the garbage can.
 
Told ya I was probably over thinking it! Thanks for that verbal shaking Russell! So, now let me see if I can get just a little more clarification on something, you said, take the green and purple wires and plug them directly into the new pcm. Is there two vss inputs on the new pcm? Or do I tie the two together? And then It's the wire coming from the new pcm that i want to tie into the cruise module/speedo right?
 
Ok, heres a good one. How about the neutral safety switch. How does that get hooked up to the new PCM? Sounds like its kinda not needed but that its a good idea. Looks like pin 34 on the blue connector.
 
Wow y'all are starting to confuse me.:confused:

That is why I got the adapter from Advance Adapters that has the VSS in it for the computer.
And then I will can just use the cable on my 205 for the speedometer.:D
 
I woulda done the same thing if it werent for my suburban already having an electronic speedo in it.
 
http://lt1swap.com/99-02_vortec_pcm.htm

So from the above link, it looks like the VSS input to the pcm is pin 21 on the red/green connector and the vss output to speedo and cruise module is (as Russel said) pin 50 also on the red/green connector. What im still unsure of, is what exactly from the VSS gets hooked up to the PCM. Is it just one of the wires from the vss to the 21 pin? Or do i tie two of them together? Or do each of them have a spot on the pcm and i just am not seeing the second spot?
 
Are you keep the 400 in it? Because the neutral safety switch is on the tranny on the 4L60/80E'sand that should be part of the wire harness for your 5.3.
 
The PCM has two pins for the speed sensor. One is a sensor ground, and the other is the signal itself. The VSS puts out a 40 pulse per driveshaft revolution alternating current signal. Doesn't lend itself well to a 12V square wave device like a speedometer, but offers a lot of resolution in comparison.

As for the park / neutral switch, it is actually built into the shifter assembly on the side of the transmission. No need to use the one on the side of your steering column anymore. You will need to install a cable actuated floor shifter though, unless someone makes a kit to convert the mechanical linkage on your steering column to work with the 4l60e...
 
Green wire from the VSS goes to pin 20 on the red connector, and the purple wire goes to pin 21 on the red connector. Pay very close attention to ensuring that the green and purple wires remain twisted together right from the VSS up to the PCM. They are twisted that way to eliminate AC interference with the rest of the harness as well as to protect from outside interference as well (induced voltages etc)

Pin 50 on the red is connected to one side of your 5k resistor, the other side is connected to an ignition 12V. The speedometer is connected to either the PCM pin 50 or the side of the resistor that is connected to the PCM.
 
Russell said:
The PCM has two pins for the speed sensor. One is a sensor ground, and the other is the signal itself. The VSS puts out a 40 pulse per driveshaft revolution alternating current signal. Doesn't lend itself well to a 12V square wave device like a speedometer, but offers a lot of resolution in comparison.

As for the park / neutral switch, it is actually built into the shifter assembly on the side of the transmission. No need to use the one on the side of your steering column anymore. You will need to install a cable actuated floor shifter though, unless someone makes a kit to convert the mechanical linkage on your steering column to work with the 4l60e...
Click to expand...

You just take the cable part off and put on the linkage from the 700 it all bolts right in place and yes it will have the neutral safety switch on it. Tranny guy said no problem the shaft is all the same where the shift linkage connects.
 
I guess i should have clarified, i am sticking with the th400. Russel, Thank you so very much! I think i have pretty much most of the ins and outs of the swap figured out now with your help! Oh yes there will be more questions! But for now, i think i pretty much go it!
 
You must log in or register to reply here.

Latest Posts

Top Bottom