P1634 Data Output Link Circuit Failure

Category: Powertrain - Computer and Auxiliary Controls
Severity: Check Engine Light
Applies to: F-150, Mustang, Explorer, Ranger

What does P1634 mean on a Ford?

P1634 — Data Output Link Circuit Failure. This Ford-enhanced code applies to F-150, Mustang, Explorer, Ranger.

Common causes of P1634

Open data output link wiring
Failed output driver
Corroded data connector
Aftermarket device loading the link
PCM fault

How to fix P1634

Remove aftermarket devices from the link
Test link continuity
Inspect connectors
Verify scan tool communication
Repair wiring per findings