DRV8243-Q1: DRV8243 SDO voltage

Hi team,

Customer found in VM=1.5V, DRVOFF=5V, nSleep=0V, IC no output. 

When pull up nSleep to 5V, SDO=3V

Because in customer system DRV8243 SPI is combined with TCAN1145 (SDI/SDO/SCLK), because SDO is abnormal (3V), the SPI communication is lost. Could you help share what's the possible reason SDO voltage is not normal (3V rather than 5V)? And if any way to make IC SDO normal as 5V?

Thank you

Scarlett