99 K2500 CCSB LY6 Swap

[gmech]

Shortly after buying my truck, I decided that I wanted to swap in a 6.0 I place of my 5.7. So I started doing my research and gathering info. We'll about a month and a half ago I sold my 5.7 and bought a 09 ly6. We'll to my surprise the ly6 is a gen 4 and not as straight foreword of a swap as a gen3. My goal was to save myself the better part of a grand and rework the original 09 harness. This is where the real journey begins. After countless hours of scouring the internet and a couple of dozen donuts to my local GM dealer I have gathered enough info to damn near complete my harness. Also my local truck savage yard manager has been really cool, giving me a extra harness and tcm from a 1500 truck so I could use the trans harness to connect to my original 4l80e.
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[gmech]

Truck pic

[gmech]

I am having a hard time with this. I am not sure where I need to wire my front vss wires to on my tcm connector. Also on my 4wd engage signal #1695- c4 pin 19 and transfer case hi/lo switch #1694- c4 pin 23 on the 99 harness. I am assuming they go to x1 pin 3 and 2 on the 09 harness.

[MalibuSSwagon]

Did you check out lt1swap.com?

http://lt1swap.com/geniv_harness.htm

Gen4 harness diagrams and pictures. Hopefully that helps.

[gmech]

Thanks,
I found this site awhile back, a bunch of helpful info. Unfortunately nothing for the 4l80e. I have searched hi and low for a 07-09 2500 express van, ly6, 4l80e pinout/ diagram. It would have saved me many hours.

[clinebarger]

The ISS (Input Speed Sensor) gets wired to pin 3 & pin 26 of the TCM. Polarity doesn't matter on these 2 circuits.

[gmech]

Thanks much! Just what I was looking for. Could I bother you for the rest of the pinout.

[clinebarger]

Here you go, As for the transfer case wiring, What transfer case do you have?

[gmech]

I will have to figure that out. It's a manual shift. 241??

[gmech]

Since I am using the e38/t42 to control my engine and trans, what do I do with the vss output to the abs? Can I leave it connected to my 99 pcm, or will it not work properly?

[MalibuSSwagon]

Seems the E38 outputs a ABS speed signal at pin 57 on the J1 connector. yellow/black wire. Should be 128k PPM just like the 99 PCM outputs, but I would verify that by searching some. I did a quick google search to gather that info.

[gmech]

The e38 is 128k also. I am not sure if it will be a problem if the signal is coming from the same ECM. Or does it not matter?

[clinebarger]

Originally Posted by gmech

Since I am using the e38/t42 to control my engine and trans, what do I do with the vss output to the abs? Can I leave it connected to my 99 pcm, or will it not work properly?

E38 ECM's have a VSS output for the ABS, Connecter X1, Pin 57, Circuit# 1827, Yellow & Black wire.

The VSS input to your EBCM (ABS Module) is on Connector C1, Pin E, Circuit# 1827, Yellow & black wire.

Gotta love GM, Vehicles 10 years apart have the same circuit numbers & color codes!

[gmech]

Ok, I was under the impression that the e38 would not work with my abs. What do I do with ckt. 1827 c4-11 purple (serial data) class 2 on pin g.

[gmech]

Have not had time to work on the truck lately, but it's time to make time. I really need to get this done. Last night I installed the Wix 33737 fuel filter/regulator and plumbed in the lines. Also started back on the wiring. I ended up putting the original ly6/6l90e harness that I was trying to rework and bought a new 09 Express van ly6/4l80e harness. Not sure if it's the best way to go, but at $280 cheaper than a new standalone.
The 99 pnp switch wires 771,772,773 and 776 go back into the cab on the passenger side to where I don't know? Now on the new harness they go to the t42 tcm. Can anyone the difference and do they still need to tied back in to the original 99 wires?

[BR3W CITY]

Well at least with the new harness you start from clean slate. The only problem is you may either have a lot to remove, or a bunch of un-needed stuff in the harness.

Does that harness have the BCM/CanBus stuff on it still?

[clinebarger]

Originally Posted by gmech

Have not had time to work on the truck lately, but it's time to make time. I really need to get this done. Last night I installed the Wix 33737 fuel filter/regulator and plumbed in the lines. Also started back on the wiring. I ended up putting the original ly6/6l90e harness that I was trying to rework and bought a new 09 Express van ly6/4l80e harness. Not sure if it's the best way to go, but at $280 cheaper than a new standalone.
The 99 pnp switch wires 771,772,773 and 776 go back into the cab on the passenger side to where I don't know? Now on the new harness they go to the t42 tcm. Can anyone the difference and do they still need to tied back in to the original 99 wires?

If you want the Gear Indicator Display to work....The Range switch wires need to be left hooked to the '99 body harness. (They go to the Cluster)

Tee off each Range Switch wire & run them to your TCM, The Range switch will now give inputs to the cluster & TCM.

[gmech]

Originally Posted by BR3W CITY

Well at least with the new harness you start from clean slate. The only problem is you may either have a lot to remove, or a bunch of un-needed stuff in the harness.

Does that harness have the BCM/CanBus stuff on it still?

Yes it does. I am leaving the rear o2 sensor connector on and just zip tying them out of the way. Same thing with few others that I will not be using. I am going to splice in the wires from the 09 X1 fuse connector into my 99 fuse harness. There are 2 other connectors besides the tcm and ecm connectors. I ohm the wires to find where they went to. There are a few that I haven't figured out yet. Could not ID or find pinouts anywhere for them.

[gmech]

Originally Posted by clinebarger

If you want the Gear Indicator Display to work....The Range switch wires need to be left hooked to the '99 body harness. (They go to the Cluster)

Tee off each Range Switch wire & run them to your TCM, The Range switch will now give inputs to the cluster & TCM.

That's what I was hoping.

[gmech]

I am using the (new style) pnp, AC Delco d257c. The connector is on pinned on 3,4,5,6,7 and 8. Wires 1786,772,771,773,1551 and 776.

Can I connect my 99 pnp leftover wires (from 7pin connector) to-
Pin 9- lt/gn #275 brake
Pin 10- lt/gn #24 back-up lamp
Pin 11- pnk #839 ignition 1
Pin 12- ppl #1035 ignition start
Not sure about #1737 to starter relay. Also on my 99 it has a yellow wire that come from the cluster I assume that was on pin A. On the 09 harness it goes from ecm x1-1 to pnp connector pin 3. Do I t into it ?

[gmech]

Originally Posted by gmech

I am using the (new style) pnp, AC Delco d257c. The connector is on pinned on 3,4,5,6,7 and 8. Wires 1786,772,771,773,1551 and 776.

Can I connect my 99 pnp leftover wires (from 7pin connector) to-
Pin 9- lt/gn #275 brake
Pin 10- lt/gn #24 back-up lamp
Pin 11- pnk #839 ignition 1
Pin 12- ppl #1035 ignition start
Not sure about #1737 to starter relay. Also on my 99 it has a yellow wire that come from the cluster I assume that was on pin A. On the 09 harness it goes from ecm x1-1 to pnp connector pin 3. Do I t into it ?

The yellow wire was on C2-a. Do I disconnect x1-1 #1786 and connect it to this wire. As best I can tell this is what lets the key switch know that the trans is in park or neutral. I tested it . This would be so much easier if I could find the schematics/diagrams. I assume that with the new pnp switch that these signals are through the bcm now. I pretty sure that #1737 goes to pnp switch pin 1.

[clinebarger]

'09 LY6 P/N input diagram. The TCM/Internal range switch in the 6L90E sends a ground when the shifter is in Park or Neutral.

[clinebarger]

'99 K2500 starter relay diagram.

[clinebarger]

'05 2500 Starter relay diagram, Using the newer NSS like you have.

[clinebarger]

As a suggestion, Wire Circuit 806 of the '99 harness to pin 12 of the NBSS, And wire Circuit 1035 of the '99 harness to pin 1 of the NBSS, This will give you a working neutral safety using the newer NBSS & original '99 starter relay, And never mind the ECM controlling the starter relay.