Engine Speed Input Circuit Malfunction
Our emissions expert has put together the following information about the P0725 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
- OBD II P0725
Fault Code Definition
- Engine Speed Input Circuit Malfunction
- 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 uneven shifting or slipping between gears.
Common Problems That Trigger the P0725 Code
- Defective Input/Turbine Speed Sensor
- Defective Input/Turbine Speed Sensor Wiring or Connection
- Defective Shift Solenoids
- 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
P0725 Diagnostic Theory for Shops and Technicians
There may be greater than a specified RPM difference between the rotational speed of the Input RPM Sensor and the Transmission Output RPM Sensor. This can occur during shifting or when driving at steady speeds in the same gear. It often implies that the transmission is slipping.
When diagnosing a P0725 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 P0725 can be difficult to detect.