Gear 2 Incorrect Ratio
Our emissions expert has put together the following information about the P0732 fault code. We have also included diagnostic procedures you can take to your repair shop if the mechanic is having difficulty analyzing the code.
OBD II Fault Code
Fault Code Definition
What does this mean?
The purpose of the automatic transmission is to match the engine's optimum power and torque characteristics to the driver's desired rate of acceleration and speed by auto-selecting different gear ratios or 'speeds' to power the wheels.
Code P0732 When the code P0732 is set in the Powertrain Computer, it means that the Powertrain Computer or PCM is seeing a greater than a specified RPM difference between the rotational speed of the Input RPM Sensor and the Transmission Output RPM Sensor when the vehicle is in 2nd gear. This can occur during shifting or when driving at steady speeds. It often implies that the transmission is slipping.
- Check Engine Light will illuminate
- Vehicle will not shift properly
- Decrease in fuel economy
- In unusual cases, there are no adverse conditions noticed by the driver
- In some cases, there may be performance problems, such as dying when coming to a stop after driving on the freeway and/or misfire-like symptoms
Common Problems That Trigger the P0732 Code
- Defective 2nd gear shift solenoid
- Defective 2nd gear related gear set or clutch pack
- Defective Engine Coolant Temperature Sensor
- Defective Valve Body
- Dirty transmission fluid that restricts the hydraulic passages
- Engine Misfire problem
- Internal Transmission problem
- Driveline problem
Polluting Gases Expelled
- HCs (Hydrocarbons): Unburned droplets of raw fuel that smell, affect breathing, and contribute to smog
- CO (Carbon Monoxide): Partially burned fuel that is an odorless and deadly poisonous gas
- NOX (Oxides of Nitrogen): One of the two ingredients that, when exposed to sunlight, cause smog
P0732 Diagnostic Theory for Shops and Technicians
When diagnosing a P0732 code, it is important to record the freeze frame information and then to duplicate the code setting conditions with a test drive. Pay close attention to the engine load, throttle position, RPM, and road speed because a P0732 can be difficult to detect.
One should monitor the RPM input speed and compare that to output speed RPM on a smooth, flat surface after the vehicle is warmed up and the fuel system is in a closed loop. Monitor how the 2nd gear solenoid configuration responds to an increased amount of throttle. The 2nd gear related solenoid should stay in 2nd gear and the transmission should NOT slip.
Possible causes- Low transmission fluid level
- Dirty transmission fluid
- Faulty shift solenoid D valve
- Shift solenoid D valve harness or connectors
- Shift solenoid D valve circuit is open or shorted
Tech notesWhen the a transmission solenoid is stuck off, in most cases the problem is not the electrical part of the solenoid; the problem is foreign material obstructing the mechanical function of the solenoid or the flow of the fluid through the transmission valve body. If the transmission fluid is very dirty, it is recommend changing the transmission fluid and if possible removing the transmission pan for further diagnosis. Excessive debris or metal particles on the transmission pan could be an indication that there is a transmission mechanical failure and that the transmission will need to be rebuilt or replaced. When is the code detected?The P0766 code is detected when the ECM has detected a mechanical fault with the solenoid energized, valve stuck off P0766 Description Shift solenoid valve D is turned ON or OFF by the Transmission Control Module (TCM) in response to signals sent from the park/neutral position (PNP) switch, vehicle speed and Engine Control Module (ECM
) (throttle opening). Gears will then be shifted to the optimum position.