P1891 Transfer Case Contact Plate Ground Return Open Circuit

What does P1891 mean on a Ford?

P1891 — Transfer Case Contact Plate Ground Return Open Circuit. This Ford-enhanced code applies to F-150, Super Duty, Explorer.

Common causes of P1891

• Open plate ground wire
• Corroded ground splice
• Disconnected plate connector
• Broken ground pin
• Harness damage

How to fix P1891

1. Test plate ground continuity
2. Reseat the plate connector
3. Inspect ground splices for corrosion
4. Repair the ground circuit
5. Verify position readings return