Matt,
Normally you had to calibrate the steering, by swopping the boxes you created a new error.
You need the Zapi handheld to make it drive again.
02A errors are the CombiAC errors and 06A from the EPS box.

This is the Yale version!

Technical Description:
On the above-mentioned truck series, the configuration file is present on both controllers (Combi AC1 and EPS AC0).
Swapping a controller from another truck (i.e. in order to make a troubleshooting), the configuration file stored in the controllers will be different and the error "Wrong config" will be shown (checking with Zapi Handset, otherwise 02AL33 will appear on the Full Mdi).
No errors will be immediately visible with standard BDI, all truck functions will be present, only traction will be reduced to 2Km/h.
This error / behaviour informs you that the controller connected to the node 2 or node 6 has a wrong configuration file.
With the following procedure you will be able to copy the configuration file from the controller already installed on the truck to the new one.