Using Second Hand Parts for Repairs

Michael from Clinton Mobile Technician Posted   Latest  

Yesterday I was called to a shop that had replaced the PK3 (TDM, Immobilizer) on a 2011 GMC Acadia. I used the VTD learn in TIS to Web only to find the immobilizer lamp remained on. I then attempted the lengthy manual process with the same result. In speaking with the owner, it was discovered that the module installed was a second hand part. In reading the codes, There was a B3031 Code in the module. It seems that the module was stuck in learn mode. In the service information it states that if the PK3 module does not exit learn mode in 10 minutes, then replace the module. In researching how the system works, it seems that the PK3 module is in some way married to the original vehicle it was installed. So even though I had gone through the process, the PK3 module rejected the keys I attempted to learn to it. Once a new replacement was installed, everything worked fine.

As we start to work on newer vehicles that are coming to the aftermarket, we see these situations more and more. In my business, we have seen this with the ECM/PCM/DME. Since about 2000 BMW has made it difficult to marry a used computer to their product line. Over the last year, my company has invested in tools that can overcome this. First BMW, then VAG and now Mercedes. I have been seeking some solutions for GM Global A cars. We have a couple of solutions for them. The list of vehicles goes on. We can now make a clone copy of may ECUs. This saves many $$$ on the Euro vehicles. It is still a work in progress.

In this "Green" society we live in, it makes little environmental sense to manufacture a "one time" part. We are told it is driven by the insurance industry. Some modules are just not worth it. The more expensive ones are worth working on.

So back to the PK3 module. I am wondering if we could all share the modules we have found that cannot be switched without having repercussions. Below is my list....

GM Global A PCMs. Do not seem to marry to new vehicle. revbase​.​com/BBBMotor/TSb/D…, youtube​.​com/watch?v=IeB3T…

GM Transmissions with integral modules. VIN Mismatch. 

BMW DME Approx 2001 and newer. Will not marry to Immobilizer. No Start.

BMW Transmissions Approx 2001 and newer. Will not shift into gear.

Mercedes Engine ECU Approx 2000 and newer. No Start.

Hyundai and KIA Engine ECUs 2004 and newer. No easy way to change VIN

Ford and Mazda Transmissions Approx 2010 and newer. Will work but VIN Mismatch.

VW/Audi ECU/PCM Approx 2004 and Newer. Component Protection, Rotating PIN code, VIN Mismatch.

VW/Audi Transmission Control Module. Starting around 2002. Component Protection, VIN Mismatch.

Chrysler WIN/WCM/SKIM Typically once the info is shared by ECU it cannot be edited with OEM tool. Some specialty tools can edit.

Chrysler PCM. Be aware that if connected an on too long the PCM will corrupt the WIN/WCM/SKIM module with the wrong VIN. Otherwise used can be mated. Tested up to 2014.

Dodge RAM w/Cummins Diesel. Not sure on years. By updating the module, the VIN is wiped clean. Must use DRBIII or DRBIII emulator to write VIN. Autoland Scientech tool can write VIN 

on some Cummins ECU.

Subaru ECUs. Can program keys to ECU but VIN is embedded.

Please share your experiences with second hand electronically controlled parts that would not work....


Craig from Watkinsville


Mobile Technician

Hi Michael,

Thanks for the post. Having a "field tested" database like this could be very valuable.

I did have one question concerning where you stated, "GM Transmissions with integral modules. VIN Mismatch". Is this in reference to the Global A Vehicles? 

The reason I ask is, I often get called out to program used GM 6 Speed Transmissions, where the TCM is mounted inside of the Transmission, and have never had a problem, as long as it is not a Global A Vehicle. Was just curious as what issues you have encountered.




Michael from Clinton


Mobile Technician


The vehicles I have run into are the smaller passenger cars. They may very well have been Global A. They worked fine and I don't recall a Check Engine lamp. Only that I could not force the VIN to take the VIN of the vehicle I was working on. Thank you for bringing this up. Maybe something to watch.


Jaime from Ocala




It's a well-known fact we are NOT to try and put used modules in GM Global A vehicles.

However, there recently was a discussion on iATN started by a mobile tech who apparently had more free time on his hands than most of us, and happened to have more smarts than I. He used a EEPROM Reader / Writer to force a used module to work properly in a GM Global A vehicle by erasing the stored VIN, then writing the correct VIN into the chip. I believe there was a video posted of his shenanigans on FaceBook too.

My latest experience was when a used car refurbishing company tried to put a used PSCM in a 2015 Cobalt. I told them prior to leaving my house about it but they insisted I try my best. I was able to successfully program that PSCM to the vehicle but when I went to perform VTD Relearn, the BCM "went offline". It LITERALLY took itself off the network, which meant there would be NO COMMUNICATION with anything but the PCM (in Generic OBDII only). It went into "protect mode" as I call it, to prevent the vehicle from being stolen is my guess as to what GM would say. My cynical statement is they do it to sell more modules, and ultimately cars when the modules become obsolete next week.

After dissipating all the capacitors in the Cobalt, all modules reported on the network again but the security light was again blinking and the VTD had not been learned. When I tried it again, the same results occurred.

So, when they say don't put used modules in a Global A vehicle, they mean it!


Michael from Clinton


Mobile Technician


Being able to virginize or clone used parts could be a great business. The curious guy that I am, I have been able to make clones of some VW/Audi and Mercedes ECUs. I have started experimenting with GM PCMs. Some the VIN is easy to find in the flash and others it is either encrypted or stored in a different spot in the PCM. For the $300 to $400 that a new PCM costs, it is not cost effective if it is not an easy process. Cracking the PSCM is worthwhile as they are very expensive. There is little information out there on the PSCM architecture, so an uphill battle there.

Remember the Toyota ECUs that married to the first 2 keys and were not re-programmable to additional keys after that? Some savvy techs figured out that one can rewrite the small memory chip and make the ECU virgin again. We will have solutions to the GM Global A problems. It will just take time to crack the security.


Jaime from Ocala



I agree Michael, that it WILL be a lucrative business, and it will most likely take off due to the forced obsolescence of parts. The description of the process used was rudimentary so it appeared the most difficult part these days was how to carefully open and reseal the ECU, not the rewriting of the EEPROM. I'd suspect the process wouldn't vary much whether it's a PCM or a PSCM. Once the VIN is blank, the security re-learn would go smoothly.

Yes, I remember well the $1,800.00 lost Master Key fob mistake one of my customers made.


Chris from Commack


Technical Support Specialist

Ford and Mazda Transmissions Approx 2010 and newer. Will work but VIN Mismatch?

Not sure which Ford transmissions this applies to, with the exception of the Diesel Super Duty the TCM should be integrated back into the PCM. There would be a solenoid strategy mismatch, but the VIN shouldn't be an issue and the Solenoid ID's can easily be written with IDS or FJDS. Some of the more recent ABS modules (2014 F150 specifically, I don't have a complete list of these) will not rewrite the vin without performing inhale from original module. Ford SRS modules will not accept a vin rewrite no matter what I try. Other than that I have been able to install used modules in just about any Ford I have tried.


Michael from Clinton


Mobile Technician

I have just figured out how to correct the VIN on KIA vehicles with Continental SIM-2K240 ECUs. I really wanted to be able to make them with a blank VIN so they could be rewritten easily. Tried a couple of methods but came up empty. It is more than just writing 0s to the HEX code. I think I would need a new ECU to figure it out.


Eric from Portland



I recently attended a class covering VW repair and the use of ODIS. The instructor mentioned that in the US, the steering lock module on many late model cars is a single use part, but in other parts of the world it isn't. Apparently, the protection isn't in the part, it's in ODIS. If you have a US based ODIS login, they just don't give you the option, but if you have a login from another country, you can do it. 

Apparently the going price is $80 for some chinese guy to remote into your computer and perform the procedure rather than buying a new lock module. 

I wonder how common this is? Are other manufacturers limiting our access to repairs simply because they think Americans can afford to replace rather than repair?


Michael from Clinton


Mobile Technician

I believe that the Abrites tool will marry a steering lock module. I did one on a Touareg a couple of years ago. Not sure about used. The Abrites does many VAG functions.