P0828 Up and Down Shift Switch Circuit High

P0828 indicates a high signal in the up/down shift switch circuit. The manual shift request circuit is stuck high or has an open/high voltage condition.

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 interpret this as a commanded shift failure until the high switch circuit is corrected.

Symptoms of P0828

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 P0828

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

Measure switch signal voltage, pull-up behavior, ground integrity, and continuity while operating each manual shift control.
Inspect for open circuits, short-to-voltage faults, connector spread, corrosion, clock spring faults, and liquid damage at the shifter.
Compare high circuit behavior with gear display, manual-mode entry, and both upshift and downshift switch data.

Related OBD-II codes

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