Child Acceleration & Vehicle Fall Sensor to KILL Engine

int obstaclePin3 = 3;  // This is our input pin (Rotation)
int obstaclePin4 = 4;  // This is our input pin (Hand Sensor 1of4)
int obstaclePin5 = 5;  // This is our input pin (Hand Sensor 2of4)
int obstaclePin6 = 6;  // This is our input pin (Hand Sensor 3of4)
int obstaclePin7 = 7;  // This is our input pin (Hand Sensor 4of4)

int hasObstacle3 = HIGH;  // HIGH MEANS OBSTACLE (Rotation)
int hasObstacle4 = LOW;  // LOW MEANS NO OBSTACLE
int hasObstacle5 = LOW;  // LOW MEANS NO OBSTACLE
int hasObstacle6 = LOW;  // LOW MEANS NO OBSTACLE
int hasObstacle7 = LOW;  // LOW MEANS NO OBSTACLE
int fall = HIGH; // HIGH MEANS VEHICLE HAS NOT FALLEN

void setup() {
  pinMode(LED_BUILTIN, OUTPUT);
  pinMode(obstaclePin3, INPUT);
  pinMode(obstaclePin4, INPUT);
  pinMode(obstaclePin5, INPUT);
  pinMode(obstaclePin6, INPUT);
  pinMode(obstaclePin7, INPUT);
  pinMode(8, OUTPUT);
  pinMode(9, INPUT_PULLUP);
  Serial.begin(9600);  
}
  
void loop() {
  hasObstacle3 = digitalRead(obstaclePin3); //Reads the output of the obstacle sensor from the 7th PIN of the Digital section of the arduino
  hasObstacle4 = digitalRead(obstaclePin4);
  hasObstacle5 = digitalRead(obstaclePin5);
  hasObstacle6 = digitalRead(obstaclePin6);
  hasObstacle7 = digitalRead(obstaclePin7);
  fall = digitalRead(9);

  if (fall == LOW)
  {
    Serial.println("Engine Killed - fall");
    digitalWrite(LED_BUILTIN, HIGH); // Open the main scooter KEY circuit
    digitalWrite(8, LOW); // no power to relay
    delay (5000);
    digitalWrite(LED_BUILTIN, LOW);
    digitalWrite(8, HIGH); // no power to relay
  }
  else if (hasObstacle3 == HIGH)
  {
    Serial.println("Engine is in running condition1");
    digitalWrite(LED_BUILTIN, LOW);//Illuminates the 13th Port LED
    digitalWrite(8, HIGH); // no power to relay
  }
   else if (hasObstacle3 == LOW && hasObstacle4 == HIGH && hasObstacle5 == HIGH && hasObstacle6 == HIGH && hasObstacle7 == HIGH)
  {
    Serial.println("Engine is in running condition1");
    digitalWrite(LED_BUILTIN, LOW);//OFF the 13th Port LED
    digitalWrite(8, HIGH); // no power to relay
  }
  
  else
  {
    Serial.println("Engine Killed");
    digitalWrite(LED_BUILTIN, HIGH); // Open the main scooter KEY circuit
    digitalWrite(8, LOW); // no power to relay
    delay (5000);
    digitalWrite(LED_BUILTIN, LOW);
    digitalWrite(8, HIGH); // no power to relay
 }
}