P0735 Gear 5 Incorrect Ratio

P0735 indicates gear 5 incorrect ratio. The controller sees input and output speed relationship outside fifth gear limits.

Code details

Generic OBD-II · P0

System: Transmission
Code type: Generic (SAE / ISO controlled)
Standard: SAE J2012 / ISO 15031-6

Diagnostic boundary

A diagnostic trouble code reports that a monitored test failed. It does not prove one specific part is bad, and manufacturer logic can add vehicle-specific conditions.

Do not assume fifth gear clutch failure until sensor and hydraulic data support it.

Symptoms of P0735

Harsh, delayed, or slipping shifts, or being stuck in one gear.
Check-engine light, sometimes with limp-home mode.
Flaring RPM or a shudder under load.

Common causes of P0735

Low or degraded transmission fluid.
A failing speed sensor, shift solenoid, or pressure-control circuit.
Wiring, connector, or internal hydraulic/mechanical faults.

Useful checks before replacing parts

Review commanded fifth gear, actual ratio, input speed, output speed, shift timing, pressure data, and fluid temperature.
Check speed sensor data, solenoid commands, pressure-control behavior, fluid condition, and companion ratio codes.
Identify whether the fault occurs during the 4-5 shift, steady cruise, or only under higher load.

Related OBD-II codes

These nearby transmission entries can help compare wording and pin down the fault area.