LMP91000EVM: I am using LMP91000 Eval Kit with PIC32MM0064GPL036 microcontroller and I am having issue in measuring Vout

I am new to LMP91000 boards, I am trying to communicate with LMP91000 using PIC32MM0064GPL036. I am using I2C bit bang code, since this PIC doesn't have hardware modules. I do not have any sensor connected to LMP91000 eval board. I am just trying to change the bias value and check the Vout for different bias value. Even when I change the bias, the voltage at all electrodes and Vout is not changing [CE, RE: 1.57,, WE: 1.1, Vout: 2.88]. I am not sure if there is an issue with the code or LMP91000. I am simply using resistor network between CE, RE, WE. I am attaching a picture of the resistor network. Here's some lines of my code:

IO_RA1_SetValue(0); //MENB Low
TX_BUFFER_I2C3[0]= 0x00;
DRIVERI2C3__F_writeI2C3(0x90,0x01,(1),(uint8_t *)&TX_BUFFER_I2C3[0]); //Unlock
IO_RA1_SetValue(1);///MENB High
DELAY_microseconds(1000);

IO_RA1_SetValue(0);
TX_BUFFER_I2C3[0]= (0x30|0x0D); //change 0x00 to 0x0D;
DRIVERI2C3__F_writeI2C3(0x90,0x11,(1),(uint8_t *)&TX_BUFFER_I2C3[0]); //set bias REFCN
IO_RA1_SetValue(1);
DELAY_microseconds(1000);

IO_RA1_SetValue(0);
TX_BUFFER_I2C3[0]= (0x03);
DRIVERI2C3__F_writeI2C3(0x90,0x12,(1),(uint8_t *)&TX_BUFFER_I2C3[0]); //set MODECN to 3-lead cell
IO_RA1_SetValue(1);
DELAY_microseconds(1000);