Ford Codes List

Ford-enhanced trouble code lookup
for Ford, Lincoln and Mercury.

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655 Ford-enhanced codes on file

Code
P1840

Transfer Case Shift Motor Short to Battery

Category
Powertrain - Transmission
Severity
Check Engine Light
Applies to
F-150, Super Duty, Explorer, Ranger

Findings, check these first

  • Motor circuit shorted to power
  • Failed motor shorting internally
  • Chafed harness
  • Corroded connector
  • Module driver stuck on

Standard procedure

  1. Test for shorts to power
  2. Isolate the motor to see if the short follows
  3. Inspect harness routing
  4. Clean the connector
  5. Repair or replace per findings

Code lookup

Type a code above, or start from a symptom or a common code.

Press / to jump to the box. Ford-enhanced powertrain, body, chassis and network codes. Generic P0xxx codes live on OBD Codes List.

Sources and review

Review: checked against the recorded source material.

  • OBDII.pro: P1840 Ford definition

    live reference page (obdii.pro)

    Supports: Ford-family meaning for P1840: Transmission Transfer Case Shift Motor Short Circuit To Battery

    Fetched directly. obdii.pro is a publisher independent of the engine-codes family.

  • P1840 FORD Code: Meaning, Causes, and Symptoms | OBD2 Codes

    live reference page (obd2-codes.co)

    Supports: Ford meaning for P1840: Transmission Transfer Case Shift Motor Short Circuit To Battery

    Fetched directly. obd2-codes.co phrasing matches the engine-codes family, so it counts as one publisher.

Last updated 2026-09-06.

Report a correction for P1840. Include your vehicle, the issue and a source if you have one.

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