Mazda RX-8 Workshop Manual page 2373

Diagnostic procedure
STEP
INSPECT POWER SUPPLY VOLTAGE USING M-
1 MDS
Turn the ignition switch off.
Connect the M-MDS to the DLC-2.
Turn the ignition switch to the ON
position (engine off).
Access B+ PID.
Is the voltage normal?
INSPECT BATTERY
2
Inspect the battery.
INSPECTION
YesMalfunction may be temporary. Go to Step 6.
No Go to the next step.
YesGo to the next step.
ACTION