P0958 Auto Shift Manual Mode Circuit High

P0958 points to a high auto shift manual mode circuit. The mode-enable signal is open, shorted to voltage, or above the expected range.

Code details

Generic OBD-II · P0

System: Transmission
Code type: Generic (SAE / ISO controlled)
Standard: SAE J2012 / ISO 15031-6

Diagnostic boundary

A diagnostic trouble code reports that a monitored test failed. It does not prove one specific part is bad, and manufacturer logic can add vehicle-specific conditions.

Do not condemn the transmission controller until the high manual mode input is isolated from switch and wiring faults.

Symptoms of P0958

Harsh, delayed, or slipping shifts, or being stuck in one gear.
Check-engine light, sometimes with limp-home mode.
Flaring RPM or a shudder under load.

Common causes of P0958

Low or degraded transmission fluid.
A failing speed sensor, shift solenoid, or pressure-control circuit.
Wiring, connector, or internal hydraulic/mechanical faults.

Useful checks before replacing parts

Check manual mode signal voltage, ground path, open circuits, short-to-voltage faults, connector fit, and switch transition data.
Inspect shifter wiring, console connectors, spilled-liquid damage, recent trim work, and related upshift or downshift inputs.
Compare high input behavior with manual mode entry, gear display, range sensor data, and freeze-frame voltage conditions.

Related OBD-II codes

These nearby transmission entries can help compare wording and pin down the fault area.