And when's the last time the fluid and filters were changed?
Should be done no less than every 50k miles, despite what the manual says (120k).
P0730 info from the service manual below:
P0730-INCORRECT GEAR RATIO
Theory of Operation
The Transmission Control Module controls the gear ratio by the use of a Step motor that transfers electrical power to mechanical movement. The rationality is a continuous test that monitors the Step motor movement. If the Step motor is stuck at a certain position, the estimated ratio is increased or decreased continuously by the feedback value of the primary pulley speed difference. When the difference between the estimated and actual primary pulley speed has reached 1000 rpm, a DTC will set.
Ignition on, engine running with the transmission in a valid forward gear.
System voltage between 9.0 and 16.0 volts.
Accelerator Pedal Position (APP) greater than 12.5% with an engine rpm greater than 450 rpm.
Vehicle speed greater than 10 Km/h (6 mph).
Transmission fluid temperature greater than 20°C (68°F).
No active DTCs from the following:
Transmission Temperature Sensor
Transmission Range Sensor
Line Pressure Solenoid
Input or Output Speed Sensor
Primary or Secondary Pressure Sensor
If the difference between the transmission estimated pulley speed and the measured primary pulley speed is greater than 1000 rpm (belt slipping) for the continuous period of 5.0 seconds.
RELATED SPEED SENSOR DTCS PRESENT
STEP MOTOR PERFORMANCE
SHIFT VALVE STICKING
CVT BELT SLIPPING