Powertrain, generic · Transmission

P0815 Upshift Switch Circuit

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

Tap-up and tap-down switches let the driver choose gears on an automatic (selector gate, buttons or paddles). GM, Ford and Saab all treat a shift request that appears where it is impossible – in park or neutral, at Ford also reverse – or that stays on implausibly long as a stuck switch. P0815 is the upshift switch. GM's 2019 and 2025 tables set it when 'tap up' stays on for more than 1 s in P or N, or permanently in a drive range; the 2018 hybrid table uses 2 s in P/N and 655 s in drive; type C without MIL. Ford's 6R80 and 6F35 SelectShift report a switch closed in P, R or N without MIL. On Saab's 9-4X with the 6T70 a Hall switch feeds a resistor network on one wire: a short to positive sets P0815 or P0816, a short to ground or an open sets P0826. Manual shifting is then disabled.

Likely causes

Tap switch or paddle sticking or faulty
Signal wire shorted to positive
Selector assembly (Hall sensor, resistor network) faulty
Clockspring or steering wheel wiring (paddles)

Symptoms

  • Manual up shifting not working
  • Transmission stays in the normal automatic mode
  • No check engine lamp

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–600
Time0.5–2.5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

tap shift switchgear selectorswitch wiringtransmission control module

Related codes

P0816P0826P0827P0828P0819

References: gsi.ext.gm.com, gsi.ext.gm.com, gsi.ext.gm.com, newtonnet.co.uk.