Mazda RX-8 Workshop Manual page 4111

Engine coolant temperature
Less than 40 °C {104 °F}
40 °C {104 °F} or more and less than 70 °C {158 °F} 6,500 rpm
70 °C {158 °F} or more
If the variable red zone is not displayed normally, verify if the PCM and
instrument cluster DTCs are output using the M-MDS.
Fuel gauge
Using the input/output check mode
1. Inspect the fuel gauge by setting it to check code 23 of the input/output check mode. (See
INSTRUMENT CLUSTER INPUT/OUTPUT CHECK
Using M-MDS
1. Connect the M-MDS to the DLC-2.
2. Measure the fuel amount in the fuel tank using the PCM data monitor item "FLI".
If any DTCs are output, perform the corresponding DTC
inspection.
If any DTC is not output, replace the instrument cluster.
6AT
5,000 rpm
7,500 rpm
MODE.)
6MT
5,000 rpm
7,000 rpm
9,000 rpm