Powertrain, generic (extended)

P2776 Upshift Switch Circuit Low

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

P2776 means the upshift switch input has dropped below the lowest voltage the module accepts. In GM's 2023 twin-clutch TCM the TAPUP input is supposed to stay above 2.519 V even with the paddle pulled; a lower reading, held for at least 150 ms with battery voltage between 8.75 and 18 V and the engine not cranking, sets P2776 as Type C without MIL. Ford's 2024 TR9070 summary assigns P2776 to the out-of-window-low case of the upshift paddle. A low reading normally means the signal wire is touching ground, for example chafed at the clock spring, or the switch is shorted inside. Compared with P2775 the value is clearly outside the band, and P2777 is the mirror image. Tap upshifts stop working while normal automatic driving continues.

Likely causes

Signal wire shorted to ground, e.g. in the clock spring area
Paddle switch shorted internally
Liquid in switch or connector creating a leak path to ground

Symptoms

  • Upshift paddle or tip function inoperative
  • Manual mode message, no check engine light on GM

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€60–500
Time0.5–2 h

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

Parts involved

upshift switchwiring harness

Related codes

P2775P2777P2778P0815P2780

References: gsi.ext.gm.com, fordservicecontent.com.