P0730 – Incorrect Gear Ratio

P0730 Possible Symptoms

Engine Light ON (or Service Engine Soon Warning Light),Incorrect transmission shifting

P0730 Possible Causes

Low transmission fluid level,Dirty transmission fluid,Shift solenoids,Transmission mechanical problems,Transmission hydraulic control circuit

P0730 Description

This diagnosis monitors actual gear position by checking the torque converter slip ratio calculated by Transmission Control Module (TCM) as follows: Torque converter slip ratio = A x C/B A: Output shaft revolution signal from speed sensor (revolution sensor) B: Engine speed signal from Engine Control Module (ECM) C: Gear ratio determined as gear position which TCM supposes If the actual gear position is higher than the position supposed by TCM, the slip ratio will be more than normal. In case the ratio exceeds the specified value, TCM judges this diagnosis malfunction.