dayj1

iTrader: (1)

I'm in the middle of a 5.3 swap into an '86 Chevy Silverado. The donor is a '07 Chevy Silverado. I've got the complete LY5 engine, 4L60E transmission, factory engine/trans harness, underhood fuse block, DBW pedal assembly, E38 ECU and transmission controller.

I want to modify my own harness to make it stand alone. I've tried to do my homework and have answered most of my initial questions. I bought the Alldata schematics for the donor truck and scoured the forums for information, but I'm still looking for a few answers.

1) I don't have the BCM, but could get it. Is it necessary for the engine and transmission to run? (If the answer to this question is "yes", some of the following questions may be irellevant)

2) Can the ECU be programmed to ignore the alternator controls? In the Gen IV setup, the current draw is monitored by the BCM which commands the ECU (via the CANBUS) to switch on the alternator's regulator.

3) Is the fuel level signal to the ECU necessary? Can the ECU be programmed to ignore it?

4) Is a terminating resistor required on the high speed bus at the DLC? I ask this because I will only be using the ECU and TCM. The ECU has a built-in termintator, but the other end of the bus (at the DLC) won't have one unless I add it.

5) Is the accessory wake-up signal to the ECU and TCM necessary? From the schematic, it appears to be a 12V signal that is passed through BCM when the switch is in the "run" or "acc" position (instead of serial data).

Thanks in advance for any direction on the questions above.

V8Rumble

iTrader: (9)

No, I'm pretty confident (99%) that it's not. IIRC, lots of people run without the BCM.

Again, I'm 99% confident that it's not required (and I'd better be right on that, since that's how I have MY swap planned out!).

BTW - I'm not being critical, but you have two #3 selections in your original post...

dayj1

iTrader: (1)

I couldn't think of a reason why the fuel sender would be needed, but I found this post a coule of days ago that made me second guess myself; https://ls1tech.com/forums/11607662-post15.html If it is needed, I don't see why wou couldn't just put an appropriate sized resistor (in my case 40 ohm) between ground and the fuel level input to the ECU. That way the computer would always see a full tank of gas and I could just run my sending unit wires to the stock gauge.

I fixed that. Thanks for your input!

alocker

iTrader: (10)

See above

dayj1

iTrader: (1)

Thanks alocker.

drmatt

Hey, I'm trying to do the same swap right now and was wondering where you got the wiring diagrams and pinouts to be able to modify the harness? And what steps you need to make the stand alone harness. I have the e38 ECU and factory harness but i guess i still need to get the gas pedal and fuse block. Do you need the fuse block? Is there a TAC module aswell on the 08 5.3 LY5? If anyone has info on the wire diagrams and pinouts though it would be great if you were willing to share them with me as i've searched high and low on the board here and connot find them for the LY5

thanks

KENS80V

iTrader: (16)

Here is a link to the factory manuals for $5 for a 24 hour period. http://www.repairprocedures.com/login/