Arduino joystick control car bug

Hello
A friend of mine have made a car module with an Arduino that have previously worked. I have connected the arduino to a joystick, trying to program the arduino so that the joystick controls the car. The joystick works, and sends the information back that is needed. I also have an ultrasonic sensor on it, which also works.However the car does not move no matter what I do. I do not know what is the issue, please help!

#define FR 9 //turn right side wheels forward
#define BR 10//turn rights side wheels backwards
//Joystick control
#define xAxis A4
#define yAxis A5
//
#define FL 5//turn left side wheels forward
#define BL 6//turn left side wheels backward
//
#define HC_SR04_VCC 0
#define HC_SR04_TRIGGER A1
#define HC_SR04_ECHO A2
#define HC_SR04_GND 0

int Xval,Yval,Dis;
void setup(){
  pinMode(12, INPUT_PULLUP);
  pinMode(HC_SR04_VCC, OUTPUT);
  digitalWrite(HC_SR04_VCC, HIGH);
  pinMode(HC_SR04_GND, OUTPUT);
  digitalWrite(HC_SR04_GND, LOW);
  pinMode(HC_SR04_TRIGGER, OUTPUT);
  pinMode(HC_SR04_ECHO, INPUT);
  pinMode(xAxis,INPUT);
  pinMode(yAxis,INPUT);
    

  delay(5000); 
  
  pinMode(FR,OUTPUT);
  pinMode(BR,OUTPUT);
  pinMode(FL,OUTPUT);
  pinMode(BL,OUTPUT);
  Serial.begin(9600);

}

void loop(){
  controll();
}

void controll(){
  FindVal();
  go();
  dis();
  if(Dis<15){
    Serial.print("WARNING, SHORT DISTANCE");
    Serial.print(Dis);
    Serial.println("cm");
  }
  else{
    Serial.print("distance is");
    Serial.print(Dis);
    Serial.println("cm");
  }
  
}
void FindVal(){
  Xval=map(analogRead(xAxis),0,1023,-255,255);
  Yval=map(analogRead(yAxis),0,1023,-255,255);
  Serial.print(Xval);
  Serial.print(";");
  Serial.println(Yval);
}


/////////////////////////////////////////////////////////////////////////////////////////////////////////////
void go(){
  int lf,rf,lb,rb;
  if(Xval<0){
    lb=Xval;
    rb=0;
    lf=0;
    rf=Xval;
  }
  else if(Xval==0){
    lb=0;
    rb=0;
    lf=0;
    rf=0;
  }
  else if(Xval>0){
    lb=0;
    rb=Xval;
    lf=Xval;
    rf=0;
  }
  lb=lb+Yval;
  rb=rb+Yval;
  lf=lf+Yval;
  rf=rf+Yval;

  if(lb<5){
    lb=0;
  }
  if(rb<5){
    rb=0;
  }
  if(lf<5){
    lf=0;
  }
  if(rf<5){
    rf=0;
  }
  
  analogWrite(FR,rf);
  analogWrite(BR,rb);
  analogWrite(FL,lf);
  analogWrite(BL,lb);
}


//////////////////////////////////////////////////////////////////////////////
void dis(){//works
  long duration, inches, cm;
  pinMode(HC_SR04_TRIGGER, OUTPUT);
  digitalWrite(HC_SR04_TRIGGER, LOW);
  delayMicroseconds(2);
  digitalWrite(HC_SR04_TRIGGER, HIGH);
  delayMicroseconds(10);
  digitalWrite(HC_SR04_TRIGGER, LOW);
  pinMode(HC_SR04_ECHO, INPUT);
  duration = pulseIn(HC_SR04_ECHO, HIGH);
  cm = microsecondsToCentimeters(duration);
  Dis=cm;
}
long microsecondsToCentimeters(long microseconds)
{
  return microseconds / 29 / 2;
}

What Arduino, what motor driver, what motors, what are you powering it all with?

Have you tried a simple test sketch that just runs the motors forward for a second or two then back?

Steve