What does code P1781 mean?

Q: What does code P1781 mean?

4x4 Low Switch is Out of Self-Test Range. P1781 on Ford vehicles means the four-wheel-drive (4x4) control module ran its power-on self-test and found the 4x4 Low range switch signal outside the voltage window it expects for a valid switch position. The module compares the switch input against known good low and high limits, and when the reading falls outside that range it commands the 4x4 system into a default or disabled state and stores this code.

DTC codes / Ford codes / P1781

P1781 · Ford4x4 Low Switch is Out of Self-Test Range

P1781 on Ford vehicles means the four-wheel-drive (4x4) control module ran its power-on self-test and found the 4x4 Low range switch signal outside the voltage window it expects for a valid switch position. The module compares the switch input against known good low and high limits, and when the reading falls outside that range it commands the 4x4 system into a default or disabled state and stores this code.

SystemPowertrain

Code typeFord specific

SeverityMedium

Fix difficultyIntermediate

AreaTransmission

Guidance is general and written for Ford vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.