P0827 Up and Down Shift Switch Circuit Low

P0827 points to a low signal in the up/down shift switch circuit. The manual shift request circuit is pulled low or missing expected voltage.

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 replace the shifter assembly until the low circuit has been isolated with electrical testing.

Symptoms of P0827

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 P0827

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 up/down switch voltage, reference feed, ground, signal return, connector fit, and possible short-to-ground conditions.
Compare scan-tool switch status with actual paddle, lever, or button operation in both upshift and downshift directions.
Inspect shifter or steering-wheel wiring, clock spring paths where applicable, and shared circuits with other manual-mode inputs.

Related OBD-II codes

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