Technical Description of OBD-II Trouble Code
The Shift Solenoid B is stuck in the “on” position.
What does that mean?
This is a generic diagnostic trouble code (DTC) for transmission issues and is typically found in OBD-II vehicles with automatic transmissions.
This can apply to various vehicle brands such as Chrysler, Ford, Dodge, Hyundai, Kia, Ram, Lexus, Toyota, Mazda, Honda, VW, etc. However, the specific repair steps may vary depending on the year, make, model, and powertrain configuration.
Most automatic transmissions have three solenoids: A, B, and C. The trouble codes related to the “B” solenoid are P0755, P0756, P0757, P0758, and P0759. These codes indicate specific malfunctions that trigger the PCM to set the code and illuminate the Check Engine Light. These codes can also be associated with the A, B, or C solenoid circuit. If your vehicle has an Overdrive or other transmission warning lamp, it may also be illuminated.
The purpose of the Shift Solenoid Circuit is for the PCM to monitor the shift solenoids, manage fluid movement between hydraulic circuits, and change the transmission gear ratio at the appropriate time. This process optimizes engine performance at the lowest RPM possible.
Automatic transmissions rely on bands and clutches to change gears. This is achieved by maintaining fluid pressure in the right place at the right time. The transmission solenoids open or close valves in the valve body to allow transmission fluid to flow to the clutches and bands, enabling smooth shifting as the engine accelerates.
When the Powertrain Control Module (PCM) detects a malfunction in the Shift Solenoid “B” Shift Circuit, various codes can be triggered depending on the specific vehicle, transmission, and number of gears. In this case, the P0757 OBD-II trouble code indicates a detected stuck on transmission Shift Solenoid “B”.
Example of shift solenoids:
What is the severity of this DTC?
This code typically starts as moderate in severity but can rapidly progress to a more severe level if not corrected promptly.
What are some of the symptoms of the code?
Symptoms of a P0757 trouble code may include:
What are some of the common causes of the code?
Possible causes for this P0757 transmission code may include:
What are some P0757 troubleshooting steps?
Prior to troubleshooting, it is recommended to research the Technical Service Bulletins (TSB’s) for the specific vehicle by year, model, and transmission. This can save time by providing guidance in the right direction. It is also important to check the vehicle records to determine when the filter and fluid were last changed, if possible.
Fluid & Wiring Inspections
The first step is to ensure the fluid level is correct and inspect the fluid for contamination. Then, visually inspect the associated wiring for any obvious defects such as scraping, rubbing, bare wires, or burn spots.
Next, check the connectors and connections for security, corrosion, and damaged pins. This includes all wiring and connectors to the transmission solenoids, transmission pump, and the PCM. Additionally, inspect the transmission linkage for security and binding issues, depending on the configuration.
Advanced Steps
The advanced steps are vehicle-specific and require appropriate advanced equipment for accurate diagnosis. These procedures involve using a digital multimeter and referencing the specific technical data for the vehicle. Voltage requirements will vary based on the specific year and model. It is important to follow the specific troubleshooting chart for the vehicle.
Continuity Checks
Continuity checks should always be performed with the power removed from the circuit. Normal readings for wiring and connections should show 0 ohms of resistance, unless otherwise specified by the technical data. Resistance or no continuity indicates faulty wiring that is open or shorted and must be repaired or replaced.
What are some common repairs for this code?
We always recommend seeking professional service to address this issue. However, if that is not possible, we offer the option to permanently delete this specific DTC while keeping all other codes active. If you are interested in this option, please upload your ECU file to our portal.
