Powertrain, generic · Transmission

P0854 Drive Switch Input Circuit Low

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. P0854 means the D signal stays at a low level: a short to ground or a contact stuck in its grounded state. Which range then appears wrongly depends on how the contact is wired.

Likely causes

Signal wire shorted to ground
Contact stuck closed
Module input

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

P0853P0855P0851P0705

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