EV Diagnostics
Source-backed diagnostic reference

P1820 EV diagnostic code

Internal Mode Switch Circuit A Low

Reference status: This page preserves source-backed code definitions for discovery. Manufacturer/model applicability, repair steps and safety conclusions are not treated as verified unless a manufacturer-specific verified report is available.

Reference definitions

  • BUICK: Internal Mode Switch Circuit A Low Source
  • CADILLAC: Internal Mode Switch Circuit A Low Source
  • CHEVY: Internal Mode Switch Circuit A Low Source
  • FORD: Transmission Transfer Case Clockwise Shift Relay Coil Circuit Failure Source
  • GM: Internal Mode Switch Circuit A Low Source
  • GMC: Internal Mode Switch Circuit A Low Source
  • LINCOLN: Transmission Transfer Case Clockwise Shift Relay Coil Circuit Failure Source
  • MERCURY: Transmission Transfer Case Clockwise Shift Relay Coil Circuit Failure Source
  • OLDSMOBILE: Internal Mode Switch Circuit A Low Source
  • OTHER: Transmission Transfer Case Clockwise Shift Relay Coil Circuit Failure Source
  • SATURN: Internal Mode Switch Circuit A Low Source
  • VOLKSWAGEN: Pressure Control Solenoid 2 Short To B+ Source

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