20/40 MHz Coexistence in 2.4 GHz

hello. pls help.  How change coexistence bit in stock factory firmware 

# wl obss_coex_action
   send OBSS 20/40 Coexistence Mangement Action Frame
   Usage: wl obss_coex_action -i <1/0> -w <1/0> -c <channel list>
    -i: 40MHz intolerate bit; -w: 20MHz width Req bit;
    -c: channel list, 1 - 14
    At least one option must be provided

but  
# wl obss_coex_action -i 0 -w 1 -c 6

wl: Undefined error

# wl obss_coex_action -i 0 -w 1 -c 6

wl: Undefined error

# wl obss_coex_action -i 0 -w 1 -c 6