Powertrain, generic · Transmission

P0855 Drive Switch Input Circuit High

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

The drive switch input reports to the engine or gearbox module that range D is selected, usually through its own contact in the range switch or selector next to the park/neutral contact. No maker documents these codes; GM's tables up to 2025, Ford's summaries and Saab service data were searched. The description follows California's rule for inputs, circuit and plausibility checks, and the documented park/neutral input, which is checked against the gearbox module's range. P0855 means the D signal stays at a high level: an open wire with the pull-up lifting the input, a short to voltage or a contact that no longer closes.

Likely causes

Signal or ground wire open
Contact worn or misadjusted, does not close
Short to voltage

Symptoms

  • Fault stored, MIL depending on maker
  • Gear indicator wrong
  • Cruise control not working

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€60–400
Time0.5–2 h

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

Parts involved

transmission range sensorgear lever switchswitch wiringengine control module

Related codes

P0853P0854P0852P0705

References: law.cornell.edu, saabwisonline.com.