P0729

DTC P0729 Gear 6 Incorrect Ratio

DESCRIPTION
The ECM uses signals from the output speed sensor SP2 and input speed sensor NT to detect the actual gear position (1st, 2nd, 3rd, 4th, 5th or 6th gear). Then the ECM compares the actual gear with the shift schedule in the ECM memory to detect mechanical problems of the shift solenoid valves, valve body or automatic transmission (clutch, brake or gear, etc.).

P0729:

HINT:
^ Gear positions in the event of a solenoid valve mechanical problem:





^ Gear position during fail-safe operation:
If any malfunction is detected, the ECM changes into the fail-safe mode to shift into the gear positions as shown in the table.





MONITOR DESCRIPTION
The ECM commands gear shifts by turning the shift solenoid valves "ON/OFF" and switching oil pressure to the valves in the valve body.

The DTC indicates that the sequence valve is locked in the direction the spring stretches and that shifting to the 6th gear is impossible.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS





TYPICAL MALFUNCTION THRESHOLDS





INSPECTION PROCEDURE

Steps 1-2(Part 1):

Steps 2(Part 2)-3(Part 1):

Steps 3(Part 2)-4: