DRV8809 shutting down

Hello:  I am an FAE with Arrow in Los Angeles.  I have a major customer using 100k/yr (in multiple designs) of the DRV8810.  They are seeing the chip shut down in their products in the field.  I was directed for support to the forum, although the customer would rather get someone direct. 

They are using this part with the motor configuration 0 (two steppers).

1. In the TPIC70600 datasheet pg 2, there is an example connection for one Stepper and 2 DC motor and the customer reads this as "clearly showing the VM and Vdin are different voltage sources".  But then they look at the test board (see attached pdf) and it shows these connected to the same source.   

2. Secondly, these questions are for their latest design (both in the field and in build/production):

a. VDIN1, VDIN2, VDIN3 (pins 26, 27, 28 respectively), VCP (pin 22) , and  VM (pin 29) are all connected to 24V, and all the ground pins are properly connected

b. The 8 pins RSA (pins 4, 5), RSB (10 and 11), RSC (38 and 39), and RSD (44 and 45) are connected to another 24V source that they can control ON and OFF

They want to know if the two sources method can be violated for the TPIC's internally so the TPIC can shut down

3. Lastly, they want to understand if there is any leakage between the pins VCP (pin 22) , and VM (pin 29) to all the RSx (A, B, C, and D) pins

Copying here an earlier email from TI apps to the customer: 

1. Internally, are these pins (VM, RSA, RSB, RSC, RSD) connected together?  --   Answer: Internally, V_M and R_sense are not shorted together, but connected with a resistor and diode either way.  They are not isolated, but there is some impedance in the connection.
2. During the testing, we lifted the pin VM(pin#29) without connecting anything, and we still be able to measure the voltage of the pin is 22V.  Does this pin is connected to any Vdd input to this TPIC device?  --  Answer:  Does ‘without connecting anything’ mean no power was applied to VDIN?  It is difficult to comment on what voltage the pin ‘should’ be without knowing the status of all the other pin connections and external components.   ------    Customer then responded with these connections:  
   1. VDIN1, VDIN2, and VDIN3 (pin#26, pin#27, and pin#28 respectively) are connected to 24V, all the ground pins are proper connected.
   2. VCP (pin#22) is connected to 24V
   3. V_M (pin#29) floating (not connected to anything)
   4. The 8 pins RSA (pin#4 and 5), RSB (pin#10 and 11), RSC (pin#38 and 39), and RSD (pin#44 and 45) are floating
3. The 8 pins RSA (pin#4 and 5), RSB (pin#10 and 11), RSC (pin#38 and 39), and RSD (pin#44 and 45) as the spec stated, they are the input pins.  At the time the TPIC is power, if the pins didn’t connect to the input source, what is the expected voltage that we can measure from these pins?  -- You may observe a voltage close to V_M, due to the connections mentioned in #1. However, during normal operation there should be a sense resistor between V_M and R_sense.

This is extremely urgent -- please comment on every issue --  thanks for the support. 

regards, George Biner, FAE Arrow LA