P0758 is a transmission control system code indicating an electrical malfunction in Shift Solenoid B (also known as Shift Solenoid 2). This solenoid is responsible for directing hydraulic fluid to engage specific gears during shifts. The 'Electrical' designation means the powertrain control module (PCM) or transmission control module (TCM) has detected a circuit problem—such as an open, short, or abnormal resistance—rather than a hydraulic failure.
The solenoid coil has internally failed, causing an open or short circuit that prevents proper electrical operation.
Wiring to the solenoid is chafed, melted, broken, or shorted to ground or power, often due to heat or age.
The connector at the solenoid or TCM is corroded, bent, or has broken pins, causing high resistance or intermittent connections.
Severely degraded fluid or low fluid level can cause solenoid malfunction codes, though this is more common for hydraulic faults.
The TCM itself may have failed, though this is relatively uncommon compared to external circuit issues.
The engine computer rarely causes this code; it should only be considered after all other causes are definitively ruled out.
Almost never. The PCM/ECM is the least likely cause of this code. In the vast majority of cases, the problem is the solenoid itself, its wiring, or the connector. Replacing the PCM is a common misdiagnosis that wastes money.
Driving is not recommended. The transmission may shift harshly, slip, or enter limp mode, leaving you with limited gear selection. Continued driving can cause additional transmission damage.
P0758 occurs across many vehicle makes and models, particularly in older vehicles with higher mileage. It is one of the more common transmission solenoid codes.
It might if the fluid is severely contaminated or low, but this is relatively uncommon for an 'Electrical' code. More often, the solenoid or wiring is the actual culprit.