Diagnosis and Repair Approaches for GM Multiple Diagnostic Interface (MDI) Tool Hanging during POST

In this video we review, diagnose, and attempt board level repair for three defective GM Multiple Diagnostic Interface (MDI) J2534 units. All three fail the power on self test (POST). One is a Chinese replica (aka clone) of the GM MDI scan tool interface, and two are genuine Bosch ETAS manufactured units for GM. If you have an MDI unit where one of the green LEDs stays stuck during POST, or you get the red error LED lighting up during POST, then this video may be helpful for diagnosis and repair techniques. We were able to successfully repair all three MDIs thru board substitution techniques, but only two thru actual board level secondary reflow approaches.
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Chapters:
0:00 - Overview of failure cases
0:21 - Case of red error LED on power up
1:01 - Case of red error LED and no beep on power up
1:37 - Case of hanging on green PC icon LED on power up
2:14 - Diagnosing root cause of POST errors using a serial interface cable
6:38 - Disassembly of a clone MDI design
8:30 - Diagnosing root cause thru CPU board substitution
9:41 - CPU board components and specifications
11:05 - Disassembly of PC and vehicle interface boards (clone version)
12:48 - Repair approaches for this case
13:54 - Disassembly of a genuine MDI
14:49 - Diagnosing root cause thru CPU board substitution
18:27 - Disassembly of PC and vehicle interface boards (genuine version)
19:56 - Diagnosing root cause thru vehicle interface (FPGA) board substitution
21:44 - Revision differences on both PC and vehicle interface boards
25:28 - Some corrections on the previous CPU board substitution test
27:34 - Datasheet details for secondary reflow repair attempt
31:20 - Serial port diagnostic cable pinout
32:42 - Secondary reflow repair attempt on CPU board
39:04 - Secondary reflow repair attempt on vehicle interface (FPGA) board
#drshock
Disclaimer: DrShock, the alias for the human content creator for this KZbin channel, is not responsible for any damages, injuries, losses, or liabilities associated with any repairs, upgrades, or maintenance performed on yours, or any other, product whatsoever. No warranty, express or implied, is made as to the accuracy or completeness of any information provided within this channel. Viewing and using the “as-is" information of this channel is totally at your own risk. Always wear personal protection equipment and follow appropriate product manufacturer service manual guidelines with original manufacturer parts only when performing any repairs, upgrades, or maintenance upon any product.

[@creverett9]

These types of videos are awesome. love your channel epically for the tech2 stuff!

[@jonaswstrand9720]

Hello! Interesting to see how they are constructed on the inside and how to troubleshoot them. I am thinking of buying one soon. Thanks! Do you have any experience with VNCI MDI2?

[@DrShock]

Thanks, I only use OEM type tools like the GM Tech2, or the GM MDI. So I am not familiar with the aftermarket brand you mention. But there is no such thing, currently, as a 100% clone of the OEM GM MDI2 interface made by Bosch. None of the tools labeled as _MDI2_ and claiming to be such can actually handle the new special protocols that the real GM MDI2 tool provides, so they are all really just original MDI level functionality, first generation J2534 interfaces. I covered this here kzbin.info/www/bejne/oqWVq2aMmJxkabM

[@lcypher5579]

For me in particular, I find your videos MOST helpful. I've upgraded my Tech2 power supply per one of your vids. Thanks for that one. I digress...I have picked up a MDI clone (with the WIFI card). I'm looking to program modules on a 2010 SRX. What version of Windows have you found to work for the MDI using GM's SPS? Thanks again, Doc.

[@DrShock]

Thanks. Currently I use Windows 10 64bit. GM keeps a PDF of what Techline Connect supports here gsitlc.ext.gm.com/userguides/Aftermarket%20Infrastructure%20Guideline%20v1.0.pdf

[@lcypher5579]

@@DrShock Thanks for your reply. 1. Do you have to be concerned with the vehicle shutting off (push button start type) which could possibly "brick" the module? 2. I saw in an excellent vid you did on programming using an MDI. In that video, your MDI was powered from the OBD port and NOT the 12vdc external power supply? Is that correct? Thanks again, Doc for all your vids!

[@DrShock]

When you are doing an SPS2 action, you need to have a battery maintainer (not a charger) to deal with voltage drops. I have a video on the one I use in the channel. The engine should _not_ be on for an SPS2 calibration event, unless the service information specifically instructs otherwise. So shutting off is not normally of any concern, just the battery level. On power supply for MDIs I only power direct from the DLC.

[@lcypher5579]

@@DrShock I should have clarified a bit better. Realizing that the engine isn't required to be running (as you stated, unless SPS requires it) my concern is whether or not the ignition shuts itself off after so many minutes. I did watch your vid on the Powermax battery maintainers....very informative as usual. I'm looking at the 55amp version thinking that a peak draw of 55 amps would be sufficient. Look forward to your videos. Thanks again for your reply, Doc.

[@GMguy01]

I have had sd card issues with the clones, they come loose in the holder, they have a bit of glue from new but obviously not enough. Whip the sd out, quick format to fat32 and then reglue and boot the mdi in recovery mode

[@DrShock]

Yeah that can be an issue as well. Obviously _not_ what we had going on here with any of these three, but worth a try for sure.

[@danielb-c9100]

Who makes GM sending units? DEL pie.?

[@DrShock]

idk, depends on the model year, make, and vehicle. Delphi makes some, but not all.

[@danielb-c9100]

2008 chevrolet silverado

[@DrShock]

Just buy ACDelco OE and you'll get the OEM grade part. I have no idea offhand who that particular supplier would be and it could even vary within the same model year.