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

Worked as it’s designed to

Pull the grey plastic cover off, has 6 plastic tabs you have to push in with a small screw driver. Now unwrap the electrical tape you will see 2 brass colored crimps holding the positive and negative wires together and there just wrapped touching each other aka a DIRECT SHORT!!! Rewrap them separately so they cannot touch and click the grey cover back on and your good, it will work. You can replace the 12v power adapter also if your worried because it is of very low quality and just barely enough Amperage to be safe for tuning. Personally 12v-2amp or 14v-2amp or I bought an adjustable 5-24v 3amp(75w) adapter and set it to 14v and when writing or reading it maybe brings the voltage down to 13.6v-13.8v which makes me feel very safe about not bricking a PCM but the OEM power supply did work after I fixed the short, it's your choice if you want to replace it for a better unit. Still shouldn't be this way but wasn't worth returning for the price because it was so cheap. Just buying the peices seperatly would cost more so your call. Happy Gen3, Gen4 Tuning guys!

Works perfectly

You can use the pictures to compare. Like another reviewer posted, it needs refining. The splices were just wrapped together, not soldered.Overall, it worked for reading and writing P59s out of the box, power worked fine. The time it would take to source the parts and build this it would have been more than the price.

It worked great for me. Had a flex fuel sensor issue and couldn't get HP Tuner to read file though the OBD2. Plugged the ecu into this and turned off the flex fuel sensor.

All this is good for is to get you thinking about how to properly build a bench harness for tuning. I had to move the ground wires and add a 12V+ wire. Also put a switch on the 12 ign wire. The main problem is the tangs that hold the blue covers didn't engage sufficiently so they can come off easily. I give it 2 stars because after my mods I was able to read 2 ECMs but on the second ECM the blue cover came off and wedged itself to the point where I had to break the connector to get it off the ECM. I'm buying a used replacement connector off Ebay now to get this working again. Live and learn.

I purchased this so I could do off-board programming on a GM PCM (2005 Silverado 5.3.) The power supply was too small, most of the wires did not make it into the crimps, and the Ground wire did not connect to any of the ground pins of the PCM. Moving the ground, soldering all of the connections and jumper wiring it to a battery it almost worked. After programming, if you completely remove the power, the software stays but the VIN doesn't lock in, so I had to add a switch to the ignition lead, now it works fine. So really, I used the PCM connector and the DLC only, but I did get my truck done.

Check your wires