Probleme interruption PIC24F

#define USE_AND_OR
#include "constante.h"
#include "p24FJ128GA106.h"
#include "pps.h"
#include "uart.h"
#include "uart_pc.h"
#include "rs485.h"
#include "global.h"
#include "var.h"
#include "timer.h"
#include "action.h"
#include "ports.h"

#if defined(__PIC24FJ256GB110__)
_CONFIG1( JTAGEN_OFF & GCP_OFF  & GWRP_OFF & BKBUG_OFF & FWDTEN_OFF & ICS_PGx1 & FWPSA_PR32 & WDTPS_PS1024 & WINDIS_OFF)
_CONFIG2( IESO_ON & FNOSC_FRCPLL & FCKSM_CSDCMD & OSCIOFNC_ON & IOL1WAY_OFF & POSCMOD_NONE )
#endif

unsigned char DataAvailable=0,caractere='0';

void ExtInt1(void);
void Transmission (unsigned char);
unsigned char lecture(void) ;

//************************ Interrupt service routine for INT1 ****************************
void __attribute__((interrupt,no_auto_psv)) _INT1Interrupt(void)
{
	Int1_Clear_Intr_Status_Bit;					//Clear interrupt status bit
	DataAvailable = 1;							//Set DataAvailable flag bit
	_LATB15 = 0;
}

void main(void)
{
	AD1PCFGL = 0xFFFF; //Désactive les entrée Analogique
	// Unlock Registers                                                                                                                                                                              	asm volatile ( 
		"MOV 	#OSCCON, w1	\n"
  		"MOV 	#0x46, w2 	\n"
  		"MOV 	#0x57, w3 	\n"
  		"MOV.b 	w2, [w1] 	\n"
  		"MOV.b 	w3, [w1] 	\n"
		"BCLR 	OSCCON,#6" );

	// Lock Registers
	asm volatile ( 	
		"MOV 	#OSCCON, w1	\n"
		"MOV 	#0x46, w2 	\n"
		"MOV 	#0x57, w3 	\n"
		"MOV.b 	w2, [w1] 	\n"
		"MOV.b 	w3, [w1] 	\n"
		"BSET 	OSCCON, #6" );

	TRISGbits.TRISG6 = 0;	// GG6 as output RX_ENABLE
	TRISGbits.TRISG7 = 0;	// GG7 as output TX_PC
	TRISGbits.TRISG8 = 0;	// GG8 as output DX_ENABLE
	TRISGbits.TRISG9 = 0;	// GG9 as output ON_PC
	TRISE=0xFF;				// PORTE en entrée (configuration)

	ON_PC=1;				// LTC1387 ON
	RX_ENABLE=1;			// récepteur ON
	DX_ENABLE=1;			// Emetteur ON	
	RS232_422=MODE_RS232;	// RS232 vers PC

	REN1=0;
//	DEN1=0;
	REN2=0;
//	DEN2=0;
	REN3=0;

	_TRISB15 = 0;	// RB15 as output (P5)
	_LATB15 = 1;
	_TRISB4 = 1;

	Int1_Clear_Intr_Status_Bit;

while(1)
{

 	ExtInt1();
	//Config2Int1();	
}
}

void ExtInt1(void)
{
    CloseINT1();											//Disable INT1 if enabled previoulsy
    iPPSInput(IN_FN_PPS_INT1,IN_PIN_PPS_RP12);    			//Confgiure INT1 on RP12 pin using PPS featue
	ConfigINT1(INT_ENABLE | FALLING_EDGE_INT | INT_PRI_7);	//Enable INT1 interrupt on falling edge with priority 4; INT_ENABLE=0x0008; FALLING_EDGE_INT = 0x0010; 
											
	
	while(!DataAvailable);									//wait till INT1 interrupt
	DataAvailable = 0;										//Clear the flag bit

}

void Config2Int1(void)
{
	_TRISB4 = 1;
	CloseINT1();
	iPPSInput(IN_FN_PPS_INT1,IN_PIN_PPS_RP12); 
	_NSTDIS = 0;		// Interrupt nesting is enabled(0)
	_INT1IE = 1;		// Interrupt request enabled
 	_INT1EP = 1;		// Interrupt on negative edge
	_INT1IF = 0;		// Flag

	_INT1IP0 = 1;		//Priorité
	_INT1IP1 = 1;
	_INT1IP2 = 1;
}