I remember that the L6 doesn't give out the same Error codes as that of the L8...

Perhaps that is saying something.....

Level 1 and level 6 ECU's share the same codes:

Code Fault / faulty part
1+1 Inductive REV/TDP sensor
1+2 Inductive distributor phase sensor
1+3 Ignition timing signal (ECU internal)
2+1 Inlet air temperature sensor (short circuited)
2+2 Inlet air temperature sensor (open circuit)
2+3 Coolant temperature sensor (short circuited)
3+1 Coolant temperature sensor (open circuit)
3+2 MAP sensor (short circuited)
3+3 MAP sensor (open circuit)

Level 8 ECU's have these codes:

Code Fault / faulty part
1+1 Inductive REV/TDP sensor
1+2 Inductive distributor phase sensor
1+3 Ignition timing signal (ECU internal)
2+1 Inlet air temperature sensor
2+2 Knock sensor
2+3 Coolant temperature sensor
3+1 Heated HEGO sensor (lambda sonde)
3+2 MAP sensor
3+3 Throttle position sensor