<Tr> <Th_colspan="2"> Chronology </Th> </Tr> <Tr> <Th> Predecessor </Th> <Td> <Ul> <Li> Cadillac High Technology engine (V8) </Li> <Li> LQ1 (V6) </Li> </Ul> </Td> </Tr> <Ul> <Li> Cadillac High Technology engine (V8) </Li> <Li> LQ1 (V6) </Li> </Ul> <Li> Cadillac High Technology engine (V8) </Li>

What year did cadillac fix the northstar engine