Question

2007 Saturn Vue Hybrid with engine codes P1A9Z and P1A9B. What do these codes mean?

Answer 1

There is only P1A9B not P1A9Z 

the battery temp sensor may need to be replaced if there is no harness issue. (Sensor is $111 or so and labor is 0.7 hours to replace it.)

see information below 

Temp Sensor Below 

Harness picture below 

  

Answer 2

P1A9B SATURN Code - Starter/Generator Inverter Phase U Temperature Sensor Performance
Read more: https://www.autocodes.com/p1a9b_saturn.html