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 status

Needs verification

Not yet verified against SAE J2012_202509 / J2012DA. Treat unverified rows as a lookup aid, not repair authority.

System: Transmission
Scope: iso-sae-controlled-p0
Standard: SAE J2012 / ISO 15031-6
Source: legacy-import

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.

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 fault area. They may share the same verification status as the source database.