P1857 — Volkswagen — Load Signal Error Message From Engine Control

P1857 (Volkswagen): Load Signal Error Message From Engine Control — what it means, the affected system and what to check before replacing parts.

Meaning, symptoms, causes and checks

Load Signal Error Message From Engine Control. Source catalogue definition; confirm applicability using vehicle service information.

Affected system: Powertrain

Symptoms

  • Illuminated check engine light
  • Erratic or harsh gear shifting
  • Engine stalling or reduced power
  • Transmission entering limp mode
  • Noticeable hesitation during acceleration

Possible causes

  • Faulty Mass Air Flow (MAF) sensor
  • Damaged or corroded wiring harness for engine-to-transmission communication
  • Incorrect load signal data from the Engine Control Module (ECM)
  • Faulty throttle position sensor
  • Vacuum leaks affecting engine load calculation

What to check

  • Inspect the engine wiring harness for chafing or corrosion
  • Scan the engine control module for additional fault codes related to sensors
  • Verify the mass air flow sensor signal with a diagnostic tool
  • Check live data for consistent throttle position and engine load values
  • Clear the fault code and perform a test drive to verify if the issue persists