New, never used, GM “Tech 2” style scan tool for under $300 (part 1 of 2)

So many times I have seen people crying for help diagnosing mysterious problems and almost always, the first thing that should be done is to hook the car up to a scan tool. They are not just “code readers” – a decent scan tool lets you delve into the actual data stream and see what’s going on in the car’s little tin brain, saving time, money, sanity and probably the odd marriage.

But most people don’t have a real scan tool, because good used ones sell fast and new ones cost more than the current market value of a Roadmaster wagon. I have stumbled over a possible solution.

A bit of background: I have a dedicated scan tool, the OTC 4000E, but OTC stopped supporting it in 2001 with the advent of CAN, so it’s only useful for older cars. I have a laptop interface and software (AutoEnginuity) that is fully CAN capable, but I’ve discovered does not access all the available data streams on at least one of my cars. Neither can do dealer programming. Frustrated, I was prowling the net looking for an alternative when I discovered the Chinese have cloned the GM scan tool holy grail: the Bosch/Ventronix made Tech 2.

Apparently, Ventronix farmed out the manufacture to a Chinese firm for many years. When Bosch bought Ventronix, they shopped elsewhere for their parts, but Pandora’s box was already opened, and patent protection only lasts 20 years…  The net result is that a number of Chinese vendors are offering Tech 2 scan tools at hobbyist price levels.

Now, before you rush right out and buy one, here’s the good, the bad and the ugly. I’ll add my personal experience in Part 2, for those of you that prefer to skip the research:

These are clones, not made by Bosch for sale by GM. It doesn’t take much research to find a wide array of warnings that these are shoddy reverse-engineered copies that will fail prematurely, probably taking your car with it as it bursts into flames. Proofs are offered in the form of photos showing missing components like capacitors, heat sinks and even entire chips. I also came across a warning that people have been charged for having or selling counterfeits.

Well, I was able to verify that last one. Sort of. There is an official court record of one fellow who was charged with one count of trafficking in goods bearing counterfeit marks – implying that the crime was not in selling the tool, the crime was putting the GM logo on it. (I assume he was representing it as being “the real deal”).  

I did come across reports of failures. Hardware-wise, it seems the CANdi module is the most susceptible to failure (this may be caused by connecting to the AC power adapter with CANdi module still connected to the Tech 2. CANdi modules are designed to be powered by the OBD connector). One fellow reported that his Tech2 mysteriously died after 5 months of steady use. Certain vendors stop answering e-mails once the sale is completed. However, it also seems that at least some of the Chinese vendors are replacing/repairing defective product. I have not been able to find any verifiable instances of the tool causing damage. I did come across one thread where the car would not start after use, but it turned out that the user turned off the wrong option – the car started again after that option was re-enabled. In another thread, the Tech 2 display went haywire and the car would not start – turned out the vehicle battery had dropped to 9v while playing with his new toy.  A number of people report that the hinge on the case was broken, apparently during shipping.

On the other hand, I also came across numerous "success stories", like one mechanic who did a side by side comparison ending in the comment that functionally, he couldn't tell the difference. The clone behaves exactly like the original.

Actually, most problems I read about turn out to be either user error or a cable issue. One or two problems with the onboard battery – in one case, the battery holder was soldered in backwards, in another, removing and replacing the battery cleared some sort of a glitch. A few reports of corrupted software on the memory cards – reflashing the same software version on the same card cured the problem. Some tossed the supplied card and installed the software onto a high quality memory card purchased locally (must be linear, ATA won’t work). There are also reports that the pins of some connectors are easily bent and the supplied cat5 cable used by the RS232 interface may be a bit dodgy – some are actually missing one critical wire and cannot work.

I came across this recent post from an insider in China:

“Clearly, these T2s are all made in China, to be specific, in Shenzhen,Guangdong. I believe there're 2 or 3 factories producing them, as they vary a little. There're lots of sellers on Taobao.com, which is China's ebay. They seem to be very similar. No one can really tell the differences before trying out. Same here, some are good and some are bad, even from same supplier. From my point of view, these type of product is not too cheap for lots of factories to produce. Plus the technique. So, basically, all the T2's at low prices within 1000usd are quite similar ones. And they absolutely all come from China. Maybe an OEM factory produces geniun T2, in the meantime, produces some lower cost ones to meet other markets. Otherwise, it's not that easy to have the technique to produce it to work. To cut costs, some of the electronics are replaced with different brands, including the accessories like cards, candi, wires etc. However, no one dare to change design, so they function very normally when everthing's in order. The replaces items are cheaper and more unstable, without testing I guess. Thus, we all rely on lucks. I also think all the sellers are dealers, no manufacturer is selling this. May avoid legal issue.”

By far, the biggest headache seems to be getting the Tech 2 talking to the software supplied for your computer, called “TIS2000”. This is all old technology and while some have had success with various emulators and adapters, the most reliable method is an older computer, running WinXP, and equipped with a real serial port. The software works as-is for basic stuff like graphing snapshot data, but requires a security dongle to access advanced features like reprogramming a module. There is a software crack floating around, but it requires a physical parallel port (ie: “LPT1”) and installs a driver to fool TIS2000 into believing the dongle is present at the port. The supplied software only covers vehicles up to 2007.  

Alternatively, GM offers access to their “TIS2Web” internet service for as little as $55 for 2 days. There may even be updates for older cars that came out after they discontinued the CD service. You can check for available updates car by VIN number for free before purchasing access. Finally, there’s, “GlobalTIS” and off-line backup of TIS2Web that requires activation and Java 6u45 – it won’t run on Java 7. While it can be downloaded from various torrent sites, I suspect the contents may vary depending on when the backup was taken. It may even vary by vehicle brand.(note: I just found out that GlobalTIS does not apply to North American brands. There are specific versions for Opal, Saab, etc.)

Note that while the patent protection on the tool may have expired, I think the software is probably copyrighted, and I believe copyright protection lasts for either 50 or 75 years. So while purchasing access to TES2Web is perfectly legitimate, cracks and keygens are probably illegal. I'm not promoting them, just noting they exist.

Ok, so knowing all the above, I decided to take the plunge. I purchased through AliExpress, where the payment is held in escrow so the purchaser can inspect the goods and confirm they are as advertised. I opted to buy one without the massive plastic storage case, to reduce the costs of shipping (potentially both ways). I can get a nice foam block filled case locally that won’t have a broken hinge anyway. I opted for the cheapest price available, on the assumption that there doesn’t seem to be any quality control no matter what vendor is chosen -- GM sells the Tech 2 for about $4,000, if you want quality control, buy one of those.

The cost was just under $300, including free shipping, one year of free updates and a 3 year warranty. I figure the warranty is worth the paper it’s written on, and this is a paperless transaction. The taxman extracted another $25 on delivery. Delivery time was 4 business days via DHL, and DHL phoned the day before delivery was scheduled, offering the option of paying the tax online by CC, which I did. I then needed to print out the e-mailed receipt for the driver. It also included the choice of one vehicle type card. I chose North American Operations – English.

Everything was well packaged in bubble wrap. All promised parts were present and looked good on initial inspection. All the stickers with serial numbers and names were missing from the unit – packaged in a separate ziplock bag. Over each sticker was another black, opaque sticker, covering any text. At first I assumed this was laziness or poor quality control, but then I realized it was probably to prevent legal issues – the tool is not labelled, therefore the tool is not a counterfeit, it is a clone of something on which patent protection has expired. If you choose to add the stickers to your tool, that’s your problem, not theirs.

Anyway, after reading the horror stories, I kept expecting the worst, and it wasn’t long before my fears were apparently realized. I fired it up for the first time and noticed the display was crooked – obviously something was misassembled. I set the clock and paged through some of the available screens. It all seemed to work so I opened it up and found the display screen was just sitting loose on top of the circuit board. The 4 screws intended to secure the display to the case were missing. I also noticed the corner of the main circuit board was chipped off. However, the circuit traces were unaffected and the screws easily replaced.

Looking closely, the board appears reasonably well made and properly soldered. I found the spot for the missing chips, but that’s on the rear of the display board. Probably a circuit revision as some other component incorporated an on-board equivalent over time. Not uncommon in the world of electronics. Similarly, there were clearly a few other components that had been omitted on the main board, but at least two of them appeared to be programming jumpers and some other vacant holes were just vias (connections between the two board faces).

With the display secured and case reassembled, I installed the loopback connectors (one for RS232 and one for the vehicle interface cable) and ran the self-test. Again, I thought I found the evidence of failure when the self-test coughed up “RTC Failure” (RTC= Real Time Clock), which made no sense since the clock was keeping perfect time. Some more research led me to discover that this is normal if the loopback connectors are installed when the unit is powered up. It turns out that this is a false failure, the unit should be booted up before the loopback connectors are attached and tests run.

I installed the CD software on an old computer with RS232 serial ports. Initially the two couldn’t see each other but on rebooting the Tech 2, all suddenly started working and there has been no further communication issue. TIS2000 attempted to update the software that came on the Tech 2, but it turns out the Tech 2 came with a much later version number than TIS2000, which would seem to confirm the vendor’s claim that the card was up to date, capable of interfacing with vehicles up to 2013.

There is also a CANdi module self-test, so I hooked that to the cable and powered up. Ahah! My first problem! “CANdi module not connected”. Rebooted, reseated the connector, reseated the card, all to no avail. It was about that point I remembered reading that the CANdi module is powered by the OBD2 connector, and should not be powered through the AC adapter. Ooops. Chalk another one up to PEBKAC.

So off to the driveway to connect up to an OBD2 car. Now CANdi powers up the LED and clicks merrily away before passing the self-test. Every function works perfectly. I can page through all the sensors and datastreams. It will even generate a cheesy little graph of up to 6 items at a time on-screen. I can control all the outputs for the various modules, although I’m still not sure why you would want to use a Tech2 to trigger the turn signals when there is a nice little lever conveniently located on the side of the steering column.  

Time to try it out on some old-school tech, so over to the RMW I go. Remove the CANdi, swap in the provided connector end and add the lighter socket power cord (since OBD1 did not provide a 12v supply at the connector). Again, no problems. There are fewer options on the old stuff of course, but everything that is supposed to be there was there. I tried a short test drive and recorded a couple of snapshots for downloading to TIS2000. I also queried the PCM for the serial number.

Looking up the serial on GMs database revealed that there was one update for the PCM available. The same update is on the TIS2000 CD, so that’s up-to-date for our cars. Same with my 01 Regal. With some trepidation, I reflashed both PCMs with the latest and greatest. I have not yet checked to see if it still throws a code when the air pump is disabled. That was not mentioned in the description of the update, it may be a one-off specific modification that is not included in the regular update or it may just not be mentioned in the brief and somewhat vague description. FWIW, I have not noticed any difference in the way the car runs. I can understand how someone could kill the battery in the process – the electric fan and headlights were on the whole time on the RMW and I noticed the headlights of the Regal stayed on even after the key was shut off until I manually turned them on and off, each time I accessed the programming function screen. Weird.

The Tech 2 comes with two linear (NOT ATA) pcmcia flash memory card slots. The second can be used to hold a card for other GM makes or, apparently, a blank card can be used to store extended snapshot information. I have not yet tried that, but think I will get a good second card for that purpose. And if the software card dies prematurely, I will already have a backup I can load the required software on.

Compared to my other scan tool options, I am really liking the Tech 2. The update rate seems faster than my OTC. It also faster to boot up and navigate, although the OTC remembers the last few cars it was used on, where the Tech 2 has to be reminded each and every time. Overall, the Tech 2  display is nicer and can fit up to 9 sensors on screen simultaneously; although the OTC display is more configurable, it can only fit 6 at a time – 5 in playback mode. The OTC is limited to 30 frames of recorded data per snapshot, at about 1 or 2 per second (depending on the vehicle). The Tech 2 was capturing about 5 frames per second with no obvious limit other than memory capacity.  

It’s easier to take on a test drive than a laptop (and no battery life to worry about), and more complete than either of the two laptop based tools I have. And takes waaaay less time to get started – the laptop program sits there for a good minute scanning for all possible sensors where the Tech 2 must already know what to expect of the car.

By now, several of you are thinking “all right already, just get to the point: is this thing worth it?”

In the case of our B-bodies, there’s not a host of configurable options that require the desktop software and programming capability. Yes, you can configure things like auto-lock behaviour, but then, you can do that without a scan tool anyway. From a programming perspective, I think the greatest value would be the ability to marry a replacement PCM module and VATS system (which is why I bought it), but from a diagnostic perspective, the ability to monitor and record the various sensors is invaluable. For that, you don’t need the desktop software except maybe for graphing. Same goes for the CANdi module – our cars don’t have a CAN bus, so we don’t need the module (may be handy for your wife’s newer GM though).

For the average backyard mechanic that just needs to track down the occasional problem on a GM (or subsidiary like Opal, Saab, etc.), I think it’s well worth the money. You get the power of GM’s flagship diagnostic tool at less than a tenth of the price. It may or may not be as robust (and that’s questionable – they were made in China for GM for many years), so for a shop that relies on having a working unit at all times, it may not be worth the risk. Of course, at that price, a shop could buy two or three backup units.

That said, there is an element of risk. I would not rely on a Chinese vendor’s promised warranty -- I followed several relatively recent links to “page not found” errors. If you buy one, make sure you protect yourself by using a credit card, paypal or escrow. If they demand Western Union or bank transfer, keep looking, there’s lots of other vendors out there. Check it out carefully on receipt, make sure everything works. Take care when plugging in the various connectors to avoid pin damage. There’s virtually no risk to your car when using it to read the data. The risk of damage only arises in the event the unit dies midway through updating the PCM.

It would be nice to be able to set the timing advance on my 6.5 diesel my self ,..

Timing advance? On a diesel?


Ok then. Maybe this is not the tool for you. May I suggest a pair of dull scissors, a bottle of non-toxic glue and some construction paper?

I have the OTC 4000 E and you are right about the truly MASSIVE carrying case.Kinda of overkill but it does hold all those cables,cassettes and the 3 manuals so I guess its a necessary evil.Use it on my OCC and it works great,love the recording feature as well as way it runs diagnostics without my asking.Great tool but the "Inova 3130 works on OBD I and OBD II and has more features for about 150 bucks.Yes Dwayne I know you're reply will be lenthly as well as thourough,already cancelled all plans I had made for friday so I can read your reply.
Jim

I'll try to keep this short then

But maybe you can elaborate a bit on your Innova? Looking at their website, it appears the 3130 MSRP is about $400 and the OBD1 kit is another $150, so I assume you got yours used or a killer deal. The website says the data display is updated every 30 seconds. That seems far too slow to catch intermittent problems. But perhaps you can record the datastream while driving and then review it later on your PC in greater detail? I'm not in the market for another tool right now, but others will be. Tell us the good, the bad and the ugly about yours.

Nice write up. I had been eying these things for a while now buy decided against it after reading all the bad reviews. I see it being useful to actuate the ABS pump on my Riviera which has never had a proper brake bleeding.
With this, can you delete the AIR pump and change the speedo calibration? I had read on some forums functions such as that did not work on these knock off units.

buickwagon wrote:

I'll try to keep this short then

But maybe you can elaborate a bit on your Innova? Looking at their website, it appears the 3130 MSRP is about $400 and the OBD1 kit is another $150, so I assume you got yours used or a killer deal. The website says the data display is updated every 30 seconds. That seems far too slow to catch intermittent problems. But perhaps you can record the datastream while driving and then review it later on your PC in greater detail? I'm not in the market for another tool right now, but others will be. Tell us the good, the bad and the ugly about yours.

Dont have the Inova yet but the 3140 model reads both I and II with live data for OBDII.Its under 200 bucks on Amazon!

95BRMW wrote:

Nice write up.  I had been eying these things for a while now buy decided against it after reading all the bad reviews.  I see it being useful to actuate the ABS pump on my Riviera which has never had a proper brake bleeding.

It can do that, if that's a procedure on the Riviera. It can do it on the Roadmaster and the Regal.

Quote :

With this, can you delete the AIR pump and change the speedo calibration?  I had read on some forums functions such as that did not work on these knock off units.

I don't think it's a question of something working on the GM version vs the clone. If the clone works, it will do everything the GM version will. I believe it's a matter of being a GM dealer or not. There's two kinds of calibration uploads: "Normal" and "VCI". Normal configurations are on the TIS2000 cd. "VCI" configurations are special cases and the dealer has to request a VCI number to download it from GM. It is my understanding that each VCI number is unique for a specific problem on a specific vehicle.

"Normal" configurations also seem to be somewhat vehicle specific. I was curious about the AIR pump disable, and the service bulletin indicates that the programming change will be found "starting February 2001, on the TIS 2000 version TIS 2.0/2001 data update or later". Darned if I can find it. For my 95 RMW there were updates to the transmission shifting, EGR operation, some stuff for "chuggles" and "surges", something to do with the trailer towing package and a couple of erroneous DTCs, but nothing referencing the AIR system. I installed the latest update available for my VIN, but still get the error code if I unplug the relay.

I wonder if the AIR disable was not approved in Canada or something. I found a Texas 95 wagon on eBay, borrowed the VIN from that ad and TIS2000 does list an unspecified change to the AIR system. There were some others that were not available to me and a couple for my car that were not listed for that one.

So basically, while the Tech2 can reprogram the PCM, it can only do so with a file provided by GM. Actually, I shouldn't say that -- there is a pass-through programming mode so it might be possible to do something if one had the appropriate software, but I think most PCM programming programs are designed around their own hardware. If you want to make your own "unauthorized" changes, I think you are best off with one of those third party programs. As a diagnostic tool, the Tech 2 is great. As a custom tuning tool, at least for the 95 RMW, it's pretty much useless.

On the 01 Regal, there are a bunch of options that can be activated through the Tech 2. For example, auto-lock behaviour (on/off/driver's door only, etc.) Somehow after playing around with some of that stuff, now the headlights stay on for a while after the engine is shut off. I'm not quite sure how I did that...

If I can add something regarding the utility of a Tech-2 level scan tool for these cars...

Where I see big value in a tool like this is to be able to exercise items like the transmission for diagnostic reasons.  After my last 4L60E transmission rebuild, a new friend who was a GM master tech came over with his Tech2 and was able to extensively check out the transmission.  He could command any line pressure, check the shift times, command particular gears, etc.   I had a real pressure gauge hooked up at the time and we watched that gauge respond perfectly to his test inputs.   I believe that 95% of diagnostic tools will not let you do these sorts of operations, ostensibly to protect you from yourself.   But it was HIGHLY useful in these circumstances.

As to tuning, I agree 100% that a third-party tuning software like TunerPro is better suited for that type of activity.  I DID look at trying to reflash a PCM using the Tech2 and a custom tune and the problem was getting the tune onto the Tech2, as you indicated.  

It would be an interesting test to see if your Chinese unit (TekTu? hah) could unbrick a bricked PCM.

It's funny you mention that -- I was playing a bit with the transmission controls last night, just to see what it could do. I didn't have a pressure gauge hooked up but from what I saw, you are right -- it gives you absolute control. Potentially a valuable diagnostic not just for the transmission itself. For example, one could prevent an upshift when engaging drive with the wheels raised off the ground to check driveshaft or brake drum balance. However, "with great power comes great responsibility": one could conceivably cause damage by doing something stupid like commanding 4th gear and TCC lockup at idle.

As for recovering a bricked PCM, that might depend upon just how bricked it is. I know you can change the stored VIN and completely replace the calibration with another GM calibration file, however, I think the PCM would have to respond to input in some manner. I also know you cannot reprogram a BCM, just change certain options. I wouldn't want to place any bets on recovering a completely bricked PCM. But if someone has one, I'm willing to try in the name of science!

Please define "bricked".
Thanks

"bricked", literally, "turned into a brick", as in "that's all it's good for any more because I broke it real good trying to do something in software that I wasn't supposed to, and now I can't reverse the changes".

Usually the result of trying to upload new or modified firmware to an electronic device. Sometimes happens due to an electrical glitch while uploading (eg: power loss or spike). Usually due to changing some setting with unexpected repercussions that prevents the device from operating any more. In general, a bricked device cannot be fixed by ordinary means (ie: the means that bricked it in the first place) but may be recoverable, if you are really lucky, by some low level function usually involving a "jtag header" and mysterious USB to serial converters.

Thanks Dwayne for your thorough answer and for keeping it under a thousand words!

Flasheroo wrote:

Thanks ... for keeping it under a thousand words!

Hey, this is the internet. Nobody's forcing you to make eye contact here!

Flasheroo wrote:

.....Yes Dwayne I know you're reply will be lenthly as well as thourough,already cancelled all plans I had made for friday so I can read your reply.
Jim

I LOL'd

I've used the Tech 2 a few times and its pretty awesome. With those you can follow the FSM diagnostic flow charts step by step.

what I meant by a "bricked" PCM is that a failure occurs during a reflash. What then happens is the same problem you get if you have a BIOS update failure on a computer - when the computer first powers up, the place it goes to get instructions on what to do is blank, so it has no way to communicate with anything. 1994-1997 LT1 computers have two flash chips that contain this information - one chip gets rewritten then the second, but both are erased at first. I know from personal experience that if you get a failure during the second half of the write (that's when all my write failures occurred) - the PCM will not boot up.

Perhaps the Tech2 might be able serve as a boot information source during the load-up, thereby allowing the PCM to reload the necessary memory into those chips and enabling a restoration?

I did read something in the manual about what to do if an update fails. Seems to me step one was not to shut off the ignition, just try again. If that failed, then you go back to the TIS2000 and set up the Tech 2 as if to program a brand-new replacement PCM. So it might be that programming as a brand new replacement hooks in at a low level boot stage. But I don't know, never tried it, don't have a bricked PCM to try it on.

I got a PM from a member about this, which reminded me I was going to update you all on some details. (WARNING: Flasheroo should clear his schedule before proceeding!)

First off, I have run this thing for many hours now (chasing down a mysterious intermittent problem on the Regal) with no problems. It has worked as advertised thus far, so I guess I got a good one.

One problem that someone else ran into involved the onboard DC-DC converter power supply board. A few people have noted that it can run hot. His ran too hot, let out the magic smoke and even after replacement, he has had some issues with certain functions thereafter.

Research suggests this is one area where the Chinese cheaped out. The original design used a single solid-state converter. The clone has a daughterboard of discrete components. Here is the side visible when you open up the case:


The pins are located in a rather odd arrangement to match the mounting holes in the main motherboard -- positioned to accept the original converter.

Here is the component side:



I came across this blog from a fellow who has really been digging into these. From that, I learned that the original component was a Mornsun VRB1205LD-15W

Mine never got hot, but it did get slightly warm. So I bought one of the Mornsun converters on AliExpress for about $20 with shipping:



Installation requires opening up the case and disassembling everything, of course. Remove the card and the VCI module first, remove the 6 torx screws from the back, hold it face down, lift the top off, set the straps off to one side and gently lift the two ribbon cables for the keyboard straight up out of the connectors. Remove the 4 screws securing the screen and pull it straight up to disengage the pins from the motherboard. Remove the 2 screws securing the motherboard to the back. I found I had to lift one side slightly and pull the board sideways to release the RJ-45 connector out of the case before lifting the board out. Don't use a lot of force -- it's soldered directly to the motherboard and you don't want to crack something.

Replacing the daughterboard requires some basic soldering and de-soldering tools and equipment. One of the pins is located fairly close to a SMD component, so you will need a fine-tipped soldering iron rather than a big fat soldering gun. I prefer a spring-loaded solder sucker but a bulb or desoldering braid would work too. Desolder the 5 pins from the motherboard and remove the daughterboard. The new converter will only go in one way. You will notice that there are 6 pins on the replacement -- the extra is for a "trim" function used to fine-tune the exact voltage. I don't know if it was actually used by the motherboard, but the hole was there and I soldered it in.



Reassemble. Again, it takes some careful positioning to ease the RJ-45 connector back into place. Note that the card door springs rest against notches in the motherboard. Clean the inside of the top cover window before replacing the cover. Carefully align each of the two ribbon cables and press straight down into the connectors. If you forgot the straps, you can undo the velcro and feed them in afterwards, but it is easier to slip them over the posts and hold them in place while closing the case.

Once it's all together, install the two loopback connectors, power it up and run the diagnostics.

Speaking of loopback connectors, the above blog notes that the clones usually come with a MAX202 serial chip while the original came with a MAX232. He advocates swapping out the 202 for a 232, and suggests the 202 is inferior.

I disagree. The MAX202 is actually a newer chip with more robust specifications. MAXIM themselves recommend it over the earlier version. The two are pin- and voltage- compatible. However, the MAX202 requires smaller capacitors than the original -- 0.1 microfarad instead of 1 microfarad. In theory, slightly larger capacitors are not a problem, smaller ones are, however, if the data rate is too high, it is possible that the larger capacitors won't have time to fully charge and data could be corrupted.

My suggestion: if your clone passes all self-tests (and you can run the tests individually and repeatedly to make sure) then don't change anything. Either your 202 is fine with the larger caps, or your clone came with the smaller caps. If your clone fails the tests or has trouble communicating with your desktop via the RS-232 cable, then change the caps rather than the chip.

These components are SMD devices (Surface Mount Device). They are very tiny, the caps are hardly larger than most soldering iron tips. Working with SMD devices requires a high degree of skill (and very good eyesight!). Specialized soldering equipment is generally used. Even with a very fine-tipped soldering iron, it will be difficult to impossible for the average person to replace an SMD IC chip. The average Joe will be hard-pressed to change the caps, but at least he stands a fighting chance as there are only two connections per cap. But that's just my 2¢.

The end result: works perfectly. And an added bonus: the unit no longer re-boots when you start the engine. With the old daughter board, the voltage sagged too low when the starter engaged and the unit rebooted every time the engine was started. After the reboot, I had to go through the menus, reselect the system, year, make, model, engine, etc. It was annoying. The Mornsun VRB1205LD-15W is more tolerant of low input voltage, and keeps the unit running through an engine restart. (for fun, I tested it with a variable voltage power supply, and the Mornsun kept things going down to about 8 volts).

One other modification I have made: the door interferes with inserting a card into slot 1. If you only have 1 card, then just insert it into slot 2 -- no problem. But I slightly trimmed the metal door with a Dremel tool so that slot 1 is accessible for a second card.

buickwagon wrote:

I got a PM from a member about this, which reminded me I was going to update you all on some details. (WARNING: Flasheroo should clear his schedule before proceeding!)

He has plenty of time,..

Your technical skills and patience are impressive,.unfortunately my eyes glazed over after the first paragraph,.
and i couldn't finish up the whole thing,.If i have an electronic gadget, and it doesn't work,.it gets replaced,.

Careful Nick,I might make a video about you and put it on youtube.Oh wait,I dont know how!

I decided to take the plunge and ordered one of these units from Aliexpress.  Getting it ordered was a pain, they don't take paypal and rejected my first credit card.  Second try with a different card did get it processed and shipped.
It arrived only 2 days after shipping from Hong Kong in good shape.  Mine didn't have a crooked display, everything looks to be in good shape.  It powered on OK and passed the built in diagnostics.  I hooked it up to my Riviera and the tech 2 specific functions all worked.  I was also able to successfully flash the PCM on an 07 Lucerne to match up an ebay radio with it.  I'll try it out on a B-body soon and see what it does on those, so far I'm impressed and feel it was well worth the money.

I built a must have accessory for the Tech II (and tuning PCMs in general).  It's a fairly simple bench top tuner that I made needlessly complicated with interchangeable connectors for use with LT1 PCMS (both OBDI and OBDII) and LS based PCMs.  I just need an OBD I port to use this with tuner cats.

Thank you for spending so much time and effort into your write up.

I am used to working on vehicles "pre-computer", so most of this was Greek to me, but I read every single word of it!.....at work...during a time i should not have.

why,I got mine gm tech 2 one year ago from chinacardiags.com,cheap and good scan tool

Tuita: Interesting first post. Why do I suspect that your IP address is somewhere in China?


Please read the terms of service, in particular those regarding vendors:

Quote :

Vendors:
GM Longroof has a section specifically for those wishing to sell products or services related to the Longroof community. ALL vendors must be approved in advance by the Forum Admins. Any posts started in the Vendor section without approval will be deleted without warning. Additionally, the poster will be contacted and reprimanded for said post. Currently there is no charge to be a vendor on Longroof. This may change in the future and current vendors will be notified ahead of such change.