how to diagnose a Ford F-150 Fourteenth Generation (2021-present) with a B1681 code

Solution

1. Preparation

• Gather tools and components required for the repair.
• Ensure the vehicle is parked on a flat surface, and the ignition is turned off.
• Disconnect the negative battery terminal to prevent electrical shock.

2. Inspect and Replace the Ignition Switch

• Remove the steering column cover using a screwdriver.
• Disconnect the wiring harness from the ignition switch.
• Using a multimeter, test the ignition switch for continuity:
  • Turn the switch to each position (Off, On, Start) and check for continuity across the terminals.
• If the switch fails the continuity test, proceed to replace it:
  • Remove the mounting screws and replace the old ignition switch with a new one.
  • Reconnect the wiring harness securely to the new ignition switch.

3. Check and Replace Fuses

• Locate the fuse box and identify the fuse related to the ignition system.
• Remove the fuse and inspect it for continuity; replace with a new fuse of the same amperage if necessary.
• Reinstall the fuse box cover.

4. Reconnect Battery and Test

• Reconnect the negative battery terminal.
• Start the engine and check if the check engine light is still illuminated.
• Verify the functionality of the ignition system and accessories.