P2111 code and fail safe mode

Just got my rebuilt 2005 prius after an accident. Everything seems to be fine except i'm getting P2111 throtlle body stuck open code and Prius gets into fail safe mode. According to diagnostic manual computer cuts of power to the throttle body motor and i'm stuck at driving at 1mph speed. After turning engine off and waiting for couple of minutes - everything is back to normal for next several miles. Seems like if i'm driving fast - above 42m/h using gas engine - everything is fine. It is happening when my motor switches to battery power and ....
Anyways - i did the regular clean your throttle body, watch out for MAF sensor, pull back the spring controling the butterfly. No impact - took it ot the dealer - of course they scan P2111 - manual tells them to replace throttle body - $1000. I told them no way. They cannot check anything else like power, resistance and other things i guess. I found some tutorials online - removed throttle body, cleaned up throttle sensor, looked at the gears inside. Looked normal no major damage to the plastic wheel inside. Put it back together - no more check engine light. ...Well it lasted couple of miles... back to square one.

This is what i noticed - i ran rev my car now after starting engine, in parking mode. My car starts fine - throttle body is opening up and down during revving. My issues starts happening after prius switches to battery power and cannot engage throttle. Makes sense that computer prevents battery power to be used when p2111 is showing up ( gas engine doesn't care).

My issue is obvious i guess - something with throttle body - wires, intermitten throttle body motor, bad sensor - how do i diagnose it without replacing the whole thing? Could it be something else?

 

My next steps are to check resistance on the harness to the throttle sensor and back.

Throttle Control Motor Connector
Tester Connection Specified Condition

M– (1) – M+ (2) 0.3 to 100
W at 20 C (68 F)

CHECK HARNESS AND CONNECTOR
Standard: (check for open)
Tester Connection Specified Condition

Throttle control motor (2) – M+ (E5 –6) Below 1
W
Throttle control motor (1) – M– (E5 –5) Below 1
W

Standard: (check for short)
Tester Connection Specified Condition
Throttle control motor (2) or M+ (E5–6)
– Body ground
10 kW or higher
Throttle control motor (1) or M– (E5–5)
– Body ground
10 k W or higher