Simple LS Bench Harness

[@prettyboyswa914]

Thank you so much saved my life !!!! I wasn't able to use Hp tuners with my truck due to getting "timed out" error after 100th times. so I went to the junk yard and my made the harness and was able to tune within seconds. Thanks again!

[@jeffmay1332]

On the OBD port, LT1SWAP shows different pins for serial and power than you show? Pin 2. - Serial Data - FROM the PCM. Pin 4 & 5 - GROUND - Usually only pin 5 is needed, however some scan tools/code readers will need GROUND on pin 4 as well. Pin 16 - 12v+ BATTERY - Power from 12v+ Battery source.

[@LeviFrazier1]

I just repined my obd2 port to what It said in the video so hopefully it works

[@MrJackson66]

​@@LeviFrazier1 well did it work the video way ?

[@frock512]

Ford guy here thanks for the info got my dads vats removed for him 👍🏼

[@LowbuckLS]

You're welcome, glad you found it helpful!

[@michaelrich8990]

I will say that I do like your diagram. And it is awesome that you have taken the time to put this information out there

[@rDLUS]

Pin 2 = serial Data Pin 4-5 = ground - Pin 16 = 12v+

[@iammee1111]

The power supply you borrowed from work has an output of 12v and 2a or 2000ma. You were reading the input specs.

[@twadam5218]

I recognize that book! :-) Fyi - While it works fine for reading /writing calibrations, I did recently realize that the 'switched power' being separate (using a toggle switch as you mentioned) from the constant is needed for certain cases. I didn't realize when it tells you to turn off the ignition that the PCM goes through a shutdown sequence of sorts.

[@LowbuckLS]

Ok, good to know, I might need to add a toggle switch if it causes problems in the future.

[@Haithamz]

Thank you for the clear instructions 👍🏼

[@LowbuckLS]

You’re welcome, thanks for watching!

[@Comm0ut]

When I buy a PCM from self-service salvage I slice off the connectors from the harness and am only charged for the PCM.

[@anthonylambert404]

What power supply is that? I can't seem to find it on Amazon. Thanks.

[@dynomantar9733]

You can use any ac/dc adapter with 12V--1A output. You can cut one off of all sorts of old electronics, you probly have one in a drawer

[@obfuscated3090]

For insurance a cheap bench supply lets you output more than 12v (a car battery outputting 12v even is below resting voltage and normally won't or will barely start-see battery makers for their resting voltages if curious). Any fifty dollar or so supply with good ratings should do and always verify output voltage using your multimeter. Going over 13v as shown is wise. It's discussed elsewhere. I use 14v to ensure no voltage drop from an imperfect connection.

[@timothybroce824]

Hello… my name is Timothy Broce… I’m interested in making the bench harness but I may be interested in having you delete the vats in my 2011 suburban 1500 pcm… one of my kid lost my key and I can’t start my car… how much do you charge and where would I send it…. Thank you T A Broce

[@antuanperez426]

Hey, if I use a red/blue connector for my bench harness, can I use if for blue/green computers?

[@LowbuckLS]

@@antuanperez426 yes it’s the blue connector you’ll be using so it works on both kinds of PCM’s

[@paulmeade9103]

Thanks ! Worked perfect!

[@Its_Stretch33]

So if the power adapter I used has a output of 12v will a 3000mA work? Or should I be concerned about frying the ECM? It’s my first bench harness so I’m not sure how this works…

[@LowbuckLS]

That should work fine. It's a little bigger than you'd need but that won't be a problem.

[@kenken4153]

Do you have to remove the PCM to read and write to it ? Is it possible to do it obd port inside the car not take anything apart?

[@dbizm]

Everything can be done from Inside a complete vehicle. No need to remove anything.

[@kenken-sr2vq]

Have had that issue that after you install and got the vxdiag nano to work and connect. I can read the pcm properties but cant read the eeprom fails at kernel , connection unlocked and starts then fails.

[@jensenhealey907efi]

I have watched and rewatched this video and you fail to explain if pin 9 on the OBD2 port goes to switched 12V power or if it is supposed to go to constant or battery 12V power

[@kristopherjohnson5782]

Could I flash a 5.3 and import a 6.0 onto the pcm?

[@LowbuckLS]

Yes you can, PCM Hammer has a clone function you can use to copy a 6.0 file onto a 5.3 PCM

[@kristopherjohnson5782]

@@LowbuckLS thank you! Cheers!

[@LowbuckLS]

@@kristopherjohnson5782 I’ll try and make a future video showing exactly how to do that.

[@815LSxSwaps]

Great video!!

[@LowbuckLS]

Thanks Eric

[@Jason-kn3tw]

I've watched so many of these and each every one assumes you have a OBD2 plug cut from a car with the wires attached - be nice if the wire plug positions in the OBD2 where shown for us trying to wire in a new OBD2 connector

[@LowbuckLS]

I guess that’s because me and everyone else I know just grab OBD2 connectors from a junkyard and don’t buy them new. Robert from @Bad Luck Garage has a has a quick video here that shows the pin positions: kzbin.info/www/bejne/lYe7c5qlf7iilZIsi=iDMvUmrWFPucuDjo

[@Jason-kn3tw]

@@LowbuckLS thanks yeah not many junkyards wreckers around here anymore - closing down everywhere , also just watched that other video , found it after yours cheers

[@r.joseph8911]

what is this “credits” thing about?

[@LowbuckLS]

If you’re making changes to a PCM with HP Tuners, you’ll need to purchase at least 2 credits from HP Tuners to write changes to the PCM at about $50 each. You can view the tune for free but need to pay to make changes, it’s part of their business model and how they make money. Newer vehicles with more modules and 8/10 speed transmissions sometimes require more than two credits. But all the stuff I work on is 2 credits per vehicle.

[@r.joseph8911]

@@LowbuckLS awesome, gotcha- and thank you for all the info and time you’ve taken to make these comprehensive videos! I’m brand new to this; Even if I build the DIY bench top tuning harness, I still will have to purchase a tuner “dongle” that plugs into the OBD connection, correct?

[@LowbuckLS]

@@r.joseph8911 yes that's correct. I plan on making a video soon going over the various different cables and devices you can use.

[@r.joseph8911]

@@LowbuckLS amazing. Keep up the great work, l will look out for that!! Gonna gather an old harness piece and check out the dongles

[@12vshady]

Ford guy here. Go ahead that ratty lookin junk to get LS running. When i hear the word "LS swapped " i immediately imagine a half finished junk project on CL or marketplace with a garbage motor in crap vehicle exuding the fact that someone bit off more than they can chew or afford or build.

[@wowitslou]

Thank you for making these videos. Do we have to do this with a bench harness or can we finish the swap and do this last through the obd2 port?

[@LowbuckLS]

Doing the tuning/programming through the OBD2 port when the swap is done will work fine, as long you have a a good battery. If the voltage were to dip down part way through the flashing process it could damage the PCM.

[@wowitslou]

@@LowbuckLS awesome, thanks again!