LS Gen 3 ECM Engine Programming Control Module Reader Diagnostic PCM Bench Harness w/Power Supply Fits for GM Chevy All Blue/Red & Blue/Green 1999-2007, OBD2 Port, 18 Gauge, 12 Volt

MARCH 2026!! Purchased for my 2003 suburban. I was getting a "Controller Unlocker: Timed Out" error while trying to tune the truck with HP Tuners. I removed my PCM and used this harness to try and get my laptop to communicate with the PCM and it worked perfect. Other reviews talk about wrong pinout and the power supply not working. Mine was pinned correctly and the power supply that is provided worked flawlessly as well. If you are having issues with HP Tuners try this. You probably have some interference in your wiring harness causing it not to work. 10/10 would recommend this harness!

5 stars because it does what it's intended. However, check the wiring before using. Mine was wired in reverse polarity, therefore, would not work. Furthermore, the ground pin was in the wrong spot and needed to be moved to pin one. I referred to the sloppy mechanics wiki to get the proper pin connections. Additionally, the connector to the PCM is pretty cheap and doesn't fit great. Lastly, this works just fine and does exactly what you expect it to do. I was able to read and write without upgrading the power supply though I was fully prepared and okay with doing so. UPDATE 4-16-2024, I ended up upgrading to a larger power supply as the one supplied would not work on the P59 pcm. If your on a 512 P01 pcm it should work but be ready to upgrade the power supply potentially.

Power was connect to ground and ground to power. The ground pin is in the wrong location, you will have to pin it to #1. The supplied power supply is not strong enough to support writing to the PCM. Found an old firetv power supply and that was able to get the harness to both read/write.

I was hesitant to use this with all the reviews about it being wired incorrectly. First thing I did was pull it apart and check the wiring and to my surprise, it was correct. The AC adapter was 1 amp and its working perfectly on p59/p01 so far. Ive already recovered a couple bricked p59's with success.

The harness worked for me but I did have to add a higher amp power supply 1 amp is not enough.

As expected, the wiring was incorrect. The ground wire that should go in pin 1 of the pcm connector was in pin 60 (throttle position low reference). The obd connector side was correct. I bought it knowing to check for bad wiring and expecting to need to use a better power supply, but for the price it was worth it to me. I will of course also be wiring in a switch on the ign + wire, instead of just connecting it to the always hot +12v.

Works as it should. No problem reprogramming went through.

Like everyone else said once you relocate the ground wire to the ground slot it works just fine. Although you shouldn't have to fix something you pay for to be working correctly

Muy practico!

I was a bit hesitant after reading a few negative reviews, but the unit I received works perfectly. I checked for the issues others mentioned—Pines in wrong order, and bare connections—and mine had none of those problems. Build quality seems solid, and it's doing exactly what it’s supposed to. Glad I took the chance on this one.

Had to completely re-wire. Came with power supply positive and ground reversed as well as ground pin in incorrect location. Very poor quality product.

Tried it out as soon as I got it. Wouldn't power up any computer. Did get it to work after un-taping the harness they had and separating the ,+ve and -ve power wires

Better off buying else where, Didn't come when it was suppose to, and on top of that computer doesn't read...... faulty crap.