How to modify BAFX OBD2 in to add the HS/MS CAN switch?
OBD2 connector pinout
BAFX OBD2 supports HS CAN from the stock, because Ford HS CAN completely matches to the OBD2 standards. It occupies pins 6 and 14. MS CAN bus occupies pins 3 and 11. The picture below illustrates the thing (Notes: the OBD2 jack on the picture means vehicle one, “female”. BAFX adapter one is “male”, so it is “mirrored”. Pins are often mixed up because of this. Always note pins’ numbering of the adapter’s jack!)
MSCAN and HSCAN switch scheme
The simplest way to implement the MS CAN support is to add a switch that will shift between MSCAN to HSCAN. The scheme below explains the modification (Notes: the OBD2 jack on the picture means vehicle one, “female”. Bafx adapter is male, so it is mirrored. Pins are often mixed up because of this. Always note pins’ numbering of the adapter’s jack!).
What are your need?
- Purchase a 6 pin mini-switch of ON-ON type (for example, MTS-202-A2) in any shop that sells electronic components, also prepare a wire.
- Disassemble BAFX OBD2 (carefully remove the label that hides 4 screws, unscrew them)
- Find a place for the mini-switch (most complex part of the whole operation for some devices that are extremely compact).
- Unsolder wires from pins 6 and 14 of the OBD2 jack and solder them to the 2 middle pins of the mini-switch.
- Solder 2 new wires from 2 outer mini-switch pins to pins 6 and 14 of the OBD2 jack.
- Solder 2 other new wires from 2 other outer mini-switch pins to pins 3 and 11 of the OBD2 jack.
- Check the work (it is very important to do not mix CAN-L and CAN-H wires up!) and assembly the BAFX OBD2 adapter, mark the MSCAN and HSCAN position on the device box to avoid confusion.
FORScan with MSCAN support
FORScan Version2 has support of MS CAN bus and optimized for using the HS/MS CAN switch. There is no necessity to adjust any BAFX adapter parameters for MS CAN. FORScan makes all the necessary changes in an automated mode. When FORScan establishes a vehicle connection, it analyses the vehicle configuration. Module MS CAN bus are supported, FORScan will ask user about HS/MS CAN switch.
It means FORScan doesn’t expect a presence of MS CAN and is not going to look for it. If user confirms the MS/HS switch presence, FORScan will ask user to shift the bus, for example:
Using the HS/MS CAN switch (minimize number of necessary shifts) with FORScan version 2. For example, reading DTCs in all of 5 HS CAN modules and 2 MS CAN modules will always require only 1 shift. Please share it, if this article helps you.
reference from forscan.org
- bafx mscan
- modify mscan bafx
- modify bafx ford mazda
- bafx switch
- baxf mscan hscan