bueno buscando esta mañan alguna solucion e confirmado que en c18 la libreria stdio.h no soporta numeros float
esto esta sacado del datasheep, por lo que entonces ay alguna otra solucion.
2.7.4 stdio.h Functions
The output functions defined in stdio.h differ from the ANSI defined versions with
regards to data in program memory, floating-point format support, and MPLAB C18
specific extensions.
The functions puts and fputs expect the output string to be stored in program
memory. The functions vsprintf, vprintf, sprintf, printf, fprintf and
vfprintf expect the format string to be stored in program memory.
The functions vsprintf, vprintf, sprintf, printf, fprintf and vfprintf do
not support floating-point conversion specifiers.
The MPLAB C18 specific extensions for 24-bit integers and data in program memory
are described in Section 4.7 of MPLAB® C18 C Compiler Libraries.