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Post by admin » Fri Feb 14, 2020 5:56 pm

Where can I find the engine code of my car?
Check the label present in the service booklet or somtimes in the trunk:
Why my engine isn't present in the supported engine list?
2 possible reasons:
  • your engine uses the old diagnostic protocol and the app works only with the last one; in this case there are no possibility to use the app
    your engine was never tested by me neither by some user; in this case you can try to use the app using every engine group available (setting it manually in the options menu) looking for some of them who makes readable the 12 parameters
  • your adapter quality is too low and doesn't support well the CANBUS commands
What are the confirmed unsupported engines?
These engines use the old diagnostic protocol, please see the related question to understand why they can't be added.
  • all 1.9 TDI engines
How can I understand if my engine ECU uses the old diagnostic protocol VW TP-2.0?
Based on my experience, VW engineers changed the diagnostic protocol about in years 2010-2011, depending on car model and brand.
Probably your ECU uses the old protocol if after the VAG DPF connection process (also in case of errors), pink texts at the bottom of the screen are missing

What can I do to verify if the app works with my engine?
If you think your engine uses the last diagnostic protocol, or in any case if you want to verify (in case your engine isn't present both in the supported and in the unsupported engine list), you can connect the app anche check if at least one engine group let you read the parameters. You can change the engine group in the options menu. In case you find a working group, send me a screenshot so I can verify and add your engine to the group. to be automatically recognized by the app.

Why old diagnostic protocol support can't be implemented into the app?
I've tried to analyze the old protocol because I know that many users need to know how their car works after dieselgate scandal, but I've found many problems:
  • ELM327 firmware doesn't officially support that protocol (big problem)
  • I don't have a car to be used for test and debug (another big problem)
  • support and documentation about the protocol are pretty absent, I didn't find any useful website
  • my time to spend in android development is reducing day by day and this activity would be enormous
Actually I don't have a plan to introduce the compatibility with old protocol.

Why some parameters can't be read (showing nd), there is a red dot in the corner of the field and the error counter shows continuos increasing number?
Connecting the app to not fully tested engines or to engines with firmware just updated, some parameters could be unreadable; in this case you can verify if some other engine group lets you read all parameters, but in case no group gives you good results, the better choice is to disable the unreadable parameters clicling on them (field became grayed) to avoid errors and time wasted in every data update cycle.

Why, after working regularly, suddenly the app can't connect to the adapter?
Sometimes after android firmware update or app update, the pairing between the device and the adapter breaks. In this case the best way to solve is unpair the adapter and pair it again in the bluetooth menu of your device; also an app re-installation can help.

Why my adapter works well with tons of OBD apps but doesn't work with VAG DPF?
Other apps use the OBD2 protocol that uses only 2 bytes of data to communicate; VAG DPF uses the full length 7-bytes message communication allowed by the CANBUS ISO protocol, the same used by the official VW diagnostic tester. Almost all cheap china clone OBD adapter are based on a cracked old ELM firmware, modified to work decently just with ODB2 protocol using 2 bytes and a reduced set of instructions. This is the reason why they work with all other apps.
VAG DPF requires a good adapter that fulfill the ELM327 firmware specs. Unfortunately, all vendors declare the compliance with all worldwide existing standards for their cheap products, lying shamelessly.

What's a good adapter working with VAG DPF?
Usually I recommend a good quality and not expensive adapter like:
  • Carista
  • Vgate iCar 2 Bluetooth (please note that is requires to press a button to be powered on)
  • Konnwei KW902
I don't recommend a professional adapter like ODBLink because for this kind of application its quality and speed would be wasted

Can this app force a regeneration?
VAG DPF app was developed as a read-only diagnostic tester. This because I want to avoid any kind of problem due to wrong procedures due to mistakes made by user or introduced by programming errors. The forced regeneration is a high risk process because of the risk of fire, I prefer to let this function to real professional softwares.

Why the regeneration process doesn't end with 0 grams of soot mass?
The regeneration process is based on the soot burning, started increasing the exhaust gas temperature with additional post injections. The temperature required for an active regeneration is between 550°C and 650°C and a big help comes from the self burning of the soot that increases the temperature even more. When the regeneration is near the end, the soot quantity inside the filter is very small and its self burning help is much lower than before, so to keep the same temperature range, the ECU should increase the fuel injected with the post injections. The more the soot is reduced, the more diesel must be injected, but the duration of this last regeneration phase would increase a lot and more diesel would go into the oil sump.
To avoid this very long regeneration, wasting fuel and increasing oil pollution, the ECU is programmed to interrupt the process at a reasonable soot mass value, balancing the duration and the soot reducing.
More or less, this value is near 2-6 grams, depending on the engine type.