P0730 - INCORRECT GEAR RATIO

The vehicles that use automatic transmission, have the torque converter, between the transmission and the motor, so that the output torque of the engine is higher and pushes the rear wheels of the vehicle. This DTC code is set on vehicles that have automatic transmission, and it means that there may be a problem of driving at any speed. In addition, this code does not exactly indicate a failure in relation to the transmission.

The automatic transmission is controlled by the vehicle’s computer and uses the multiple transmission ratio, in order to increase the vehicle’s speed, in addition to giving the maximum output of the engine’s power output. These vehicles can have up to 4 transmission ratios in order to save fuel.

The computer orders the moment when the change is made between the gears. Either down or up, depends on throttle position and engine speed.

Both the ECM, the PCM and the Transmission Control Module (TCM), use the input of several sensors to ensure that the transmission with its components work in the correct way The speed of the engine is usually defined against the Vehicle Speed ​​Sensor, to specify the transmission ratio and the slip torque converter. If this calculation does not the expected value, the DTC code P0730 is set.

• Turn on the service light on the Check Engine board.
• At the time of change is delayed or does not change.
• Slip of the transmission.
• Fuel consumption is more than usual.

A diagnostic code P0730 can have one or more of the following problems:

• The transmission fluid may be dirty.
• The fluid filter may be clogged.
• The pump may show wear.
• The clutch torque converter may be blocked.
• The transmission may have a mechanical malfunction.
• Perhaps there is an internal obstruction in the main control of the transmission.
• Shift solenoids may be faulty, or even their wires.
• The TCM (Transmission Control Module) may be defective.

To fix the DTC code P0730 you can check the following components:

• Verify the status of the fluid and its level. Change if you find elements that contaminate it.
• Perform a torque converter speed test using the manufacturer's references. There may be a problem with the torque converter or an internal transmission problem when the engine stall speed is not as specified. If this is the case, you can obtain additional codes to P0730.
• The solenoid that controls, internal clutches, the torque converter and the bands can have a bad electrical connection, but similarly gives another DTC code, so it solves first if it is the case.
• Perhaps the torque converter has a mechanical problem, the main control of the transmission or some problems in the pressure. Check and repair if necessary.
• With the help of a scanning tool, you must first locate the motion that commands the transmission and check if the motor speed matches the output speed calculated from the transmission sensor.