P0732 Code: Gear 2 Incorrect Ratio

Diagnostic trouble codes (DTC) are activated when there’s a problem with your car. DTCs starting with “P” are powertrain trouble codes and are set when there are mechanical or electrical failures surrounding the engine or transmission.

Diagnosing and fixing DTCs are not as easy as they sound. You need to have proper and sufficient knowledge regarding the specific code you’re dealing with. If you’re getting the P0732 code on an OBD scanner, this guide will provide the important facts you’ll need for addressing the code such as its definition, causes, and symptoms.

What Does the P0732 Code Mean?

Diagnostic trouble code (DTC) P0732 stands for “Gear 2 Incorrect Ratio.” It is commonly seen in vehicles with automatic transmissions—specifically problems shifting into or driving in 2nd gear.

This code is triggered once your PCM detects that the RPM difference between the rotational speed of your input speed sensor and the transmission output speed sensor doesn’t match what the ECM/PCM expects to see in 2nd gear.

(The P0732) code is triggered once your PCM detects that the RPM difference between the rotational speed of your input speed sensor and the transmission output speed sensor doesn’t match what the ECM/PCM expects to see in 2nd gear.

–Richard McCuistian, ASE Certified Master Automobile Technician

The gear ratio in transmissions is the ratio between the rotational speeds of two gears, which vary due to different diameters set for each gear. You can calculate the gear ratio by dividing the output speed by the input speed. But to determine the values of the two, there needs to be speed sensors for both the input and the output of the transmission. These sensors are used by the powertrain control module (PCM) or transmission control module (TCM) to compare speeds while making sure that every gear has the optimal gear ratio.

The PCM calculates transmission input shaft speed with transmission output shaft speed to get the proper gear ratio and torque converter slip. If the PCM detects that the calculation did not match its projected value, code P0732 may be set and the check engine light might be activated.

You can learn more about how codes like P0732 are set in our technical discussion about gear ratios.

Note: The definition of code P0732 may be different depending on the vehicle manufacturer. Consult the appropriate repair manual or repair database for the exact code definition.

What are the Possible Causes of the P0732 Code?

There are varying causes for code P0732, which means not all cases can be diagnosed using one method. Here are the common causes of the P0732 code to take note for proper diagnosis:

• Internal transmission failure
• Valve body issue
• Low transmission fluid level
• Contaminated transmission fluid
• Faulty shift solenoid
• An issue with the shift solenoid’s circuit
• Malfunctioning transmission control module or powertrain control module

What are the Common Symptoms of the P0732 Code?

If your OBD-II scanner is reading the P0732 code, you’re at risk of experiencing one or more of these symptoms:

• Illuminated check engine light
• Delayed shifting or difficulty shifting into 2nd gear
• Transmission slipping
• Poor fuel economy

How to Diagnose the P0723 Code

It is important to take note that incorrect ratio DTCs typically require advanced mechanical experience and special diagnostic tools. This is because there’s more than a single way of diagnosing the P0732 code. Consider consulting or bringing your car to a certified mechanic for proper diagnosis.

How to Fix the P0732 Code

One has to be cautious when diagnosing or troubleshooting a car with a running DTC, especially if it’s directly concerning the engine or other critical components like the transmission. Having proper DIY skills helps in successfully clearing any code, including P0732. If you think you don’t have enough experience and knowledge, you can bring your vehicle to a certified mechanic to clear the code.

If you’re eager to fix your car yourself, repair manuals or an ALLDATA subscription may help you. Subscribing to ALLDATA will give you access to valuable information about different problems you might encounter with your car, including the P0732 code.

Products Mentioned in this Guide

Transmission Control Module Valve Body