P0731

P0731 - INCORRECT 1ST GEAR RATIO





The Transaxle Control Module (TCM) calculates gear ratio based on the transaxle input and output speeds. The TCM compares the known gear ratio to the calculated ratio for the selected range. When the TCM detects an unknown gear ratio when 1st gear is commanded, then the DTC P0731 sets.

DTC PARAMETERS
One of the following conditions occurs for 4 seconds:
- The gear ratio is greater than 3.50:1.
- The gear ratio is between 2.23:1 and 2.87:1.
- The gear ratio is between 1.71:1 and 2.02:1.
- The gear ratio is between 1.07:1 and 1.54:1.
- The gear ratio is between 0.72:1 and 0.91:1.
- The gear ratio is less than 0.60:1.

When the following conditions have been met:
- Engine speed is between 200 RPM and fuel cut-off.
- Ignition voltage is between 8 and 18 volts.
- TP angle is greater than 15%.
- TFT between 50° C (122° F) and 130° C (266° F).
- Engine torque greater than 2 Nm (1.5 ft. lbs.).
- Commanded ratio = 1st gear.
- No engine torque default.
- Time since last manual range change greater than 6 seconds.
- TFP not in PARK or NEUTRAL.
- Vehicle speed greater than 5 km/h (3 mph).

No ISS, OSS, TFP or TP sensor DTCs have been set.
P0731 is a type C DTC.

DIAGNOSTIC AIDS
- Check for improper transaxle operation.
- Check for an incorrect calibration.