Gear Ratio Functional Check

Gear Ratio Functional Check Description

There are five gear ratio function diagnostic checks, an error is detected if:
1. All enabling conditions are satisfied and the ratio of engine speed to output shaft speed whilst 1st gear is engaged is out of range.
2. All enabling conditions are satisfied and the ratio of engine speed to output shaft speed while 2nd gear is engaged is out of range.
3. All enabling conditions are satisfied and the ratio of engine speed to output shaft speed while 3rd gear is engaged is out of range.
4. All enabling conditions are satisfied and the ratio of engine speed to output shaft speed while 4th gear is engaged is out of range.
5. All enabling conditions are satisfied and the transmission control unit has prevented a gearshift, which would have caused an engine over speed.

For the diagnostic table, please refer to the individual codes (i.e. P0721, P0731, P0732, P0733 or P0734).