General Information

Automatic Transaxle
P0731 Gear 1 Incorrect Ratio - General Information

Component Location





General Description

The ratio monitoring controls the nominal gear box ratio to the real gear box ratio. While driving in a gear (reverse, first second, third) there is a calibrated rationality check between turbine speed and output speed of the corresponding gear.
While up or down shifting from one gear to another there is a calibrated rationality check between turbine speed and output speed of the corresponding shift. While engaging the gear there is a calibrated rationality check between turbine speed and output speed of the corresponding shift if the actual output speed is higher or equal than a calibrated threshold.
While engaging the gear when the actual output speed is lower than the threshold there is a rationality check on the turbine speed.

DTC Description

TCM set this code if the value of input speed (turbine speed) is not equal to the value of the output speed, when multiplied by the 1st gear ratio, while the transaxle is engaged in 1st gear. If this code outputted, Check the Engine system first and then follow this procedure. (MIL ON : 2 driving Cycle)

DTC Detecting Condition





CAUTION :
1. The function with the higher priority will always take precedence. However, a low-priority is not overruled by a higher priority function.
2. Functions from different priority categories can also run in parallel. It is important to note which function will take precedence in this case.
3. In such an event it is possible for a substitute function with low priority not be carried out if a second, higher-priority function is present. This has been taken into account when compiling the priority list and is international.
4. The mechanical emergency run function must always have the highest priority, since from the electrical standpoint it is the only safe condition.

Signal Waveform & Data

Solenoid valve operating status according to gear position





-O- : variable control




















Fig 1) Solenoid valves in 1st gear
Fig 2) Solenoid valves in 1st gear-graph
Fig 3) Solenoid operating status - start to shift
Fig 4) Solenoid operating status - shifting
Fig 5) Solenoid operating status - down shift 2nd to 1st gear