hello you don't have steering F01 means
Ps Powersteering main circuit open
This is a AC truck but only the steering motor is A DC motor, the problem are the brusch of motor
When you change them and still got F01 You have problem wit SAS print Leftside of truck in the back There mounted transistor on it they blow away(defect) hopefull the print is okay,
Always check the brush of this type of truck
when you need more help let me no

Kindly regards
John.