P0758: Shift Solenoid "B" Electrical
The transmission control unit has detected an electrical fault in the shift solenoid B circuit.
Normal risk
Usually drivable, but shifting may be wrong or the gearbox may hold one gear. Have it checked soon.
Short answer · Can I keep driving with P0758?
Usually yes, at moderate speed. The gearbox may skip gears, shift harshly or stay in a fixed gear. Have it checked soon.
What does P0758 mean?
P0758 means the current or voltage in the shift solenoid B circuit is not plausible, for example because of an open circuit, a short or a failed solenoid coil. A damaged internal harness or a corroded connector are other typical causes. Which gears are affected depends on the transmission design.
What the car does when the code is set
The check engine light comes on. Depending on the transmission fault, shifting may be normal, harsh or delayed, or the transmission may stay in one gear (limp mode).
How the system works
An automatic transmission has its own control unit that reads speed sensors, the selector position and pressure sensors, and controls shifting through solenoids. When it detects a fault that can affect emissions, it asks the engine control unit to light the check engine lamp. Because the engine control unit stores a code for that request, a basic scanner often shows only this code, while the detailed code stays in the transmission control unit.
Common symptoms
Possible causes
Listed without ranking. The cause on your car depends on make, engine and mileage — see the maker notes below.
- Fault in the transmission control systemThis code only reports that the transmission control unit has stored its own fault.
- Low or old transmission fluidOften found together with shifting codes.
- Sensor or solenoid faultSpeed sensors, pressure solenoids and wiring.
- Communication problemBetween the engine and transmission control units.
How it is diagnosed
- Read the transmission control unitUse a scan tool that reads the transmission module: the real cause is stored there.
- Check the fluidCheck level and condition as the service data describes.
- Follow the specific codeDiagnose the code from the transmission module.
- Clear and test-driveClear codes from both modules and test-drive.
Questions about P0758
Can fresh fluid fix P0758?
If dirty fluid made a solenoid or valve stick, a fluid and filter change can help. An electrical fault needs the wiring or solenoid repaired.
Why does my basic scanner only show this code?
Many simple scanners read only the engine control unit. A scanner that reads the transmission module shows the real fault code.
Is P0700 a transmission failure?
Not necessarily. It only reports that the transmission control unit stored a fault. The real code there shows what is wrong.