BQ34210-Q1: BQ34210 register configuration

Hello,

In my current design I'm using the fuel gauge  BQ34210 and I am having issue in the software side when it comes to the configuration/update the design capacity.  I believe the issue is in the way the checksum is calculated but I don't seem to find where the error is. Attached is a snipped of my code.

void BQ34210_updateDesignCapacity(int newDesignCapacity){
    uint8_t MSB = 0;
    uint8_t LSB = 0;
    uint8_t CNFGUPDATE = 0;
    uint16_t value=0;
    uint16_t DesignCapacity=0;
    uint16_t Old_DC=0;
    uint8_t oldMACDataSum=0;
    uint8_t MACDataLen=0x24;
    uint8_t Temp;
    uint8_t New_Chksum;
    uint8_t Old_Chksum;
    uint8_t OLD_DC_MSB;
    uint8_t OLD_DC_LSB;
    uint8_t wait=0;
    uint8_t DeltaCHK=0;
    char adc_value[18];
  
    // Unseal
     CyDelay(1);
    BQ34210_writeRegister(0x00,0x1404);  
    CyDelay(1);
     BQ34210_writeRegister(0x00,0x7236);
    CyDelay(1);
    //Enter Config Update Mode
     BQ34210_writeRegister(0x00,0x0090);
    CyDelay(1);
   //  BQ34210_writeRegister(0x00,0x7236);
    //while
    while((CNFGUPDATE!=1)||(wait<12)){
    value=BQ34210_readRegister(0x3B);
    CNFGUPDATE = ((value>>8) & 0x04);
  
    CyDelay(10);
    wait++; 
    
    CyDelay(10);//prevent from getting stuck in the loop
    }
    
    //Get access to Design Capacity
    BQ34210_writeByteRegister(0x3E,0x49);
    CyDelay(1);
    BQ34210_writeByteRegister(0x3F,0x93);

    
    //Read Old Chksum sum
    Old_Chksum=BQ34210_readByteRegister(0x60);
    CyDelay(1);
    //Read MAC Data lenght
    MACDataLen=BQ34210_readByteRegister(0x61);
    CyDelay(1);
    //Get access to Design Capacity
    BQ34210_writeRegister(0x3E,0x4993);  
    CyDelay(1);
    //Get Design Capacity from MACData (0x40) 
    OLD_DC_MSB=BQ34210_readByteRegister(0x40);
    CyDelay(1);
    //Read MAC Data lenght
    OLD_DC_LSB=BQ34210_readByteRegister(0x41);
    CyDelay(1);

  //Calculate new checksum (nned to figure out this)
    Temp=Old_Chksum;
    Temp=255-Temp;
    Old_DC= (OLD_DC_MSB + OLD_DC_LSB)%256;
    DeltaCHK=Old_DC-newDesignCapacity;
    Temp=abs(Temp-DeltaCHK);
    New_Chksum=255-Temp;
    
    
   // (255-Old_Chksum-OLD_DC_MSB-OLD_DC_LSB)%256;
  //  New_Chksum=255-256%(Temp+0x04+0xB0);
    
    
     //Write new Design Capacity
    BQ34210_writeRegister(0x40,newDesignCapacity);  
    
  CyDelay(1);
    //Write new checksum
   BQ34210_writeByteRegister(0x60,New_Chksum);   
CyDelay(1);
  //Write MAC Data len  
   BQ34210_writeByteRegister(0x61,MACDataLen);   

CyDelay(80);
//Get access to Design Capacity
    BQ34210_writeRegister(0x3E,0x4993);
    CyDelay(1);
       //Read the Design Capacity
   DesignCapacity= BQ34210_readRegister(0x40);
 
    CyDelay(1);
 }

From the datasheet:

Thank you,

Sam