Autotune not start on 4S battery

ArduCopter Copter 3.4
1

Autotune not start on 4S battery but when change to 3s it work autotune started.

my quad auw 1.8kg
pixhawk
4010 850kv
10x4.5 prop
4s and 3s battery

2

now i update firmware to 3.5.2 and try autotune in PosHold mode it Work!!!