Here is a
LINK to the OBD II codes.
To read your fault code you will need a OBD II code reader connected to your OBD II port. You can borrow OBD II Scan Gauage from most auto parts stores.
You connect the reader up to the OBD II port in your coach. Federal law requires all vehicle manufactures to locate the OBD II port within one foot of the steering column on the inside of the vehicle. On my Ford F53 my port is to the right of the steering column and up under the dash. The port may have a cover and may be difficult to identify.
It may be easier to locate your port by taking digital pictures up and under your dash and then look for the port in the pictures.
Safe travels.
JD