PIC24FJ128GA202 UART2 und UART3 funktionieren nicht?

Ich arbeite in einem Mikrocontroller pic24fj128ga202 mit L80- und M95-Modul. hier L80-Modul verbunden mit uart2 und M95-Modul verbunden mit uart3. Jetzt funktioniert uart1 normal, aber uart2 und uart3 funktionieren nicht (dh) ich habe keine gps- und gprs-Daten erhalten. Unten habe ich sowohl die uart.h- als auch die ioconfig.h-Datei main.c angehängt

#include "p24FJ128GA202.h"           
#include <stdio.h> 
#define led PORTAbits.RA2
#include "UART.h"
#include "IOCONFIG.h"
int main()
{
    GSMPwrkey=1;
    init_processor();
    uartx1( uart2rx());
   return 0;
}

UART.h
#include<stdio.h>
/* transmit a character in uart1 */
void uartx1(char in_c)
{
    while(U1STAbits.UTXBF == 1);
    U1TXREG = in_c;
}
/* transmit a character in uart1 */
void uartx2(char in_c)
{
    while(U2STAbits.UTXBF == 1);
    U2TXREG = in_c;
}
/* transmit a character in uart3 */
void uartx3( char in_c)
{             
    while(U3STAbits.UTXBF == 1);
    U3TXREG = in_c;       
}
/* Receive a character in uart1 */
char uart1rx()
{
    char c;
    while(U1STAbits.URXDA == 0);
    c = U1RXREG;
    return c;       
}
/* Receive a character in uart2 */
char uart2rx()
{
    char c;
    while(U2STAbits.URXDA == 0); 
    c =U2RXREG; 
    return c;
}
/* Receive a character in uart3 */
char uart3rx()
{  
    char c;
    while(U3STAbits.URXDA == 0); 
    return U3RXREG; 
    return c;
}
/* transmit a string in uart1 */
void uartstr1( char *s)
{
    while(*s!='\0')
    {
        uartx1(*s);
        s++;
    }
}
/* transmit a string in uart3 */
void uartstr3( char *s)
{
    while(*s!='\0')
    {
        uartx3(*s);
        s++;
    }
}


IOCONFIG.h

#include<stdio.h>
#include<stdint.h>
#define GSMPwrkey PORTBbits.RB12
#define GPSreset PORTBbits.RB15
void Timer1DelaymsInit(void);
void Delayms(uint16_t delay);
void init_Processor(void);
void Timer1DelaymsInit(void)
{
    T1CONbits.TCKPS = 0; //Timer1 Prescale Select bit
    T1CONbits.TCS = 0;   //Timer1 Clock source(FOSC/2)
    PR1 = 3760;
    TMR1 = 0;
    IEC0bits.T1IE = 0;
    T1CONbits.TON = 1;

}
void Delayms(uint16_t delay)
{

    while(delay>0)
    {
        TMR1 = 0;
        IEC0bits.T1IE = 0;  //Reset interrupt flag
        while(!IEC0bits.T1IE);// Wait here for timeout
        delay--;
    }

}
void init_Processor(void)
{

  /* uart1 Tx and Rx pin setup */ 
    RPINR18bits.U1RXR = 7;      //portB RB7 RX pin
    RPOR4bits.RP8R   = 3;       //portB RB8 TX  pin
 /* uart2 tx and rx pin setup */    
    RPINR19bits.U2RXR = 14;     //portB RB14 RX pin
    RPOR6bits.RP13R   = 5;      //portB RB13 TX pin
 /* uart3 tx and rx pin setup */    
    RPINR17bits.U3RXR = 10;     //portB RB10 RX pin
    RPOR5bits.RP11R   = 19;     //portB RB11 TX pin
    //Congifure analog and digital 
    ANSA = 0x0003;                                                  
    ANSB = 0x0000;
    PORTA = 0x0000;                                                 
    TRISA = 0X001B;                                                 
    PORTB = 0x0000;                                                 
    TRISB = 0x4680;
    // Init UART1
    U1MODE = 0x8000;                                                 
    U1STA = 0x3400;
    U1BRG = 25;                                                     
    // Init UART2
    U2MODE = 0x8000;                                                
    U2STA = 0x3400;
    U2BRG = 25;                                                     
    // Init UART3
    U3MODE = 0x8000;                                                
    U3STA = 0x3400;
    U3BRG = 25;
    IFS5bits.U3RXIF   = 0;            
    IEC5bits.U3RXIE   = 1;            
    U3MODEbits.UARTEN = 1;            
    U3STAbits.UTXEN   = 1;
    // Init ADC
    Timer1DelaymsInit();
    GSMPwrkey=1;    
}