moDiag - Frequently Asked Questions
F: Is it possible to connect to older cars with moDiag?
A: moDiag is an OBD-2 scan software. This means moDiag uses the standardized and manufacturer independent protocols, which have been implemented for emission related diagnostics. These protocols have been implemented in the EU for cars with Otto engines from the year 2000/2001 on (Diesel 2003/2004).
Because OBD-2 standards where originally implemented in the USA in cars (Otto engines) from the year 1996 on, there are some vehicles in the EU (those which have been exported to the USA), which already use OBD-2 although they have been built before 2000.
But generally spoken: In the EU Otto engines before 2000/2001 and Diesel before 2003/2004 do not have OBD-2 - this means: moDiag is not suited for them! But: no rule without exception!
You can find a (incomplete) list of OBD-2 compatible cars under the following link:
F: When connecting, moDiag reports „No OBD compliant ECU found“ – what can I do?
A: There are a few reasons for this
F: Can I reset the service indicator light with moDiag?
A: No! OBD-2 protocols are standardized for "emmisions related" diagnostics. The service indicator is not emmisions related! It is a function which is implemented by the manufacturer. And every manufacturer has a different way to reset it.
F: Can I read/erase trouble codes of Anti-Lock-Brake system (Climate Control, Airbag...)?
A: No! These are not "emmissions related" systems. Therefor for these systems no standardized communication protocols exist! Every manufacturer has his own way of communication to these systems!
F: But the workshop also uses the OBD-2-connector to communicate with the Anti-Lock-Brake system (Climate control; Airbag...)?
A: The OBD-2 connector has more pins than neccessary for OBD-2-diagnostics. The manufacturer specific testers of the work shop are using other pins of the connector and - more important - different and manufaturer specific communication protocols.
F: Why can I read only the "Engine Speed" ("Vehicle Speed"...) with moDiag and not more?
A: Because the manufacturer did not allow to read more sensors over OBD-2! Like all OBD-2 scan tools, at the start of a communication moDiag will request the list of supported parameters (PIDs) from the vehicle. Based on the response to this request, moDiag builds the sensor table. The OBD-2 standards contain a lot of possible parameters, BUT most of these parameters are optional, which means, the car manufacturer is not obliged to report these values via OBD-2! Especially cars built in the first years of OBD-2 in the EU often report only a few parameters. There are even some cars which report an empty parameter table!
LPG adjustment with moDiag professional
F: Will moDiag work together with all LPG softwares?
A: Yes, moDiag will work with all Windows-based LGG softwares!
F: Do I still need the LPG adjustment software / the interface to the LPG kit?
A: Yes! moDiag is just an OBD-2 scan software and communicates to the Engines Control Unit of the car - not to the LPG kit! For the communication/adjustment of the LPG kit you will need the software and interface of the LPG kit´s manufacturer!