What causes P1820 on a Ford?

Failed clockwise shift relay Open relay coil circuit Blown transfer case fuse Corroded relay socket 4WD module driver fault

How do I fix P1820 on a Ford?

Check transfer case fuses Swap the shift relay with a known-good unit Test coil resistance Inspect the socket Verify range shifting returns

P1820 Transfer Case Clockwise Shift Relay Coil Circuit Failure

Q: What does P1820 mean on a Ford?

P1820 — Transfer Case Clockwise Shift Relay Coil Circuit Failure. Applies to F-150, Super Duty, Explorer with electric shift transfer cases.

Category: Powertrain - Transmission
Severity: Check Engine Light
Applies to: F-150, Super Duty, Explorer with electric shift transfer cases

What does P1820 mean on a Ford?

P1820 — Transfer Case Clockwise Shift Relay Coil Circuit Failure. This Ford-enhanced code applies to F-150, Super Duty, Explorer with electric shift transfer cases.

Common causes of P1820

Failed clockwise shift relay
Open relay coil circuit
Blown transfer case fuse
Corroded relay socket
4WD module driver fault

How to fix P1820

Check transfer case fuses
Swap the shift relay with a known-good unit
Test coil resistance
Inspect the socket
Verify range shifting returns