BQ76952: Custom PCB, FETs stay closed no matter what

Tool/software:

Hi, 

I'm quite new to electrical engineering and the TI platform, please excuse any mistakes I make in formating, documentation etc.

I designed custom PCB as a BMS and used the BQ76952 chip, below you can see the schematic, also with cell wiring, and a source code I test on esp32 in Arduino IDE with I2C communication. I searched web, talked to chatbots, but still could get a software solution to my problem, the charge and discharge gates are closed. Do you think there may be a problem in my schematic or cell wiring? Is there some better way to test it out than with my code? Not sure if BQSTUDIO would work? Thanks so much for your help. I appreciate every answer. 

This is the output from the code in the console

Cell 1 voltage: 3.686 V
Cell 2 voltage: 4.102 V
Cell 3 voltage: 3.686 V
Cell 4 voltage: 3.666 V
Cell 5 voltage: 0.000 V
Cell 6 voltage: 0.000 V
Cell 7 voltage: 0.000 V
Cell 8 voltage: 0.000 V
Cell 9 voltage: 0.000 V
Cell 10 voltage: 0.000 V
Cell 11 voltage: 0.000 V
Cell 12 voltage: 0.000 V
Cell 13 voltage: 0.000 V
Cell 14 voltage: 0.000 V
Cell 15 voltage: 0.000 V
Cell 16 voltage: 3.839 V
FET Status: 1110000

SCH_Schematic1_2025-04-03.pdf

#include <Wire.h>

// BQ76952 I2C address (7-bit)
#define BQ76952_I2C_ADDR 0x08

// Command addresses
#define CONTROL_STATUS 0x00
#define BATTERY_STATUS 0x12
#define CELL1_VOLTAGE_L 0x14
#define CELL1_VOLTAGE_H 0x15
#define FET_STATUS 0x7F

// Variables to track communication status
bool commEstablished = false;
int retryCount = 0;
const int maxRetries = 5;

void setup() {
  Serial.begin(115200);
  Wire.begin(21, 22, 400000);  // Initialize I2C with default pins (SDA=21, SCL=22)
  
  // Try to establish communication
  while (!commEstablished && retryCount < maxRetries) {
    if (checkCommunication()) {
      commEstablished = true;
      Serial.println("Communication with BQ76952 established successfully!");
    } else {
      retryCount++;
      Serial.print("Communication failed, retry ");
      Serial.print(retryCount);
      Serial.println("/5");
      delay(1000);
    }
  }
  
  if (!commEstablished) {
    Serial.println("Failed to establish communication with BQ76952");
    while(1); // Halt if communication fails
  }
}

void loop() {
  // Read and print cell voltages (example for cells 1-4)
  for (int cell = 1; cell <= 16; cell++) {
    float voltage = readCellVoltage(cell);
    Serial.print("Cell ");
    Serial.print(cell);
    Serial.print(" voltage: ");
    Serial.print(voltage, 3);
    Serial.println(" V");
  }
  
  // Read and print FET status
  uint8_t fetStatus = readRegister(FET_STATUS);
  Serial.print("FET Status: ");
  Serial.println(fetStatus, BIN);
  
  // Check if FETs are enabled
  bool chgEnabled = (fetStatus & 0x01) != 0;
  bool dsgEnabled = (fetStatus & 0x02) != 0;
  
  Serial.print("CHG FET: ");
  Serial.println(chgEnabled ? "ENABLED" : "DISABLED");
  Serial.print("DSG FET: ");
  Serial.println(dsgEnabled ? "ENABLED" : "DISABLED");
  
  Serial.println("---------------------");
  delay(1000); // Delay between readings
}

bool checkCommunication() {
  // Try to read the Battery Status register
  Wire.beginTransmission(BQ76952_I2C_ADDR);
  Wire.write(BATTERY_STATUS);
  if (Wire.endTransmission(false) != 0) { // Send repeated start
    return false;
  }
  
  // Request 2 bytes (Battery Status is 16-bit)
  if (Wire.requestFrom(BQ76952_I2C_ADDR, 2) != 2) {
    return false;
  }
  
  // If we got data, communication is working
  uint16_t batteryStatus = Wire.read() | (Wire.read() << 8);
  return true;
}

float readCellVoltage(int cellNumber) {
  // Calculate register addresses for the cell
  uint8_t regLow = CELL1_VOLTAGE_L + (2 * (cellNumber - 1));
  uint8_t regHigh = regLow + 1;
  
  // Read low and high bytes
  uint8_t lowByte = readRegister(regLow);
  uint8_t highByte = readRegister(regHigh);
  
  // Combine bytes and convert to voltage (mV to V)
  int16_t voltage_mV = (highByte << 8) | lowByte;
  return voltage_mV / 1000.0;
}

uint8_t readRegister(uint8_t reg) {
  Wire.beginTransmission(BQ76952_I2C_ADDR);
  Wire.write(reg);
  Wire.endTransmission(false); // Send repeated start
  
  Wire.requestFrom(BQ76952_I2C_ADDR, 1);
  while (Wire.available() < 1); // Wait for data
  return Wire.read();
}