I am unable to get my OBD2 adapter to connect with the app it is blinking on SPD and says "Waiting for OBD...", do you have any help on this issue?

Post date: 30-Oct-2015 15:21:48

The connection eventually timed out with the following message:

When we examined the diagnostic logs we found the following entries:

10-29 17:06:52.837 E/ObdCommand(28156): 01 0D
10-29 17:06:52.837 E/ObdCommand(28156): SEARCHING...
UNABLETOCONNECT

This indicates that the adapter was unable to connect to the vehicle's ECU.  Usually this is the result of not having had the ignition turned to position 2 but in this case the ignition was in position 2 with the engine running so what went wrong?

It transpires that the majority of cheap Chinese OBD2 adapters you will find on eBay are missing the components needed to support the pre-2008 OBD2 protocols SAE J1850 VPW, and SAE J1850 PWM.  In this case the vehicle was a 2006 Dodge Caravan which uses the SAE J1850 VPW protocol.

All internal combustion engine (ICE) vehicles sold in the US from 2008 onwards must support the ISO 15765-4 CAN protocol so these adapters generally work with these vehicles but before then, GM/Chrysler/Dodge and Ford tended to make use of the J1850 VPW and J1850 PWM protocols respectively.  You can read about the missing components here:  http://torque-bhp.com/forums/?wpforumaction=viewtopic&t=5155.0

If you are considering purchasing a cheap Chinese adapter and your car is pre-2008, check with the supplier that it is compatible with your make, model, and year of vehicle.