P1933 Fuel Additive Pump Control Circuit Low (Diesel)

Category: Powertrain - Fuel/Air Metering
Severity: Check Engine Light
Applies to: Ford diesel models with additive systems

What does P1933 mean on a Ford?

P1933 — Fuel Additive Pump Control Circuit Low (Diesel). This Ford-enhanced code applies to Ford diesel models with additive systems.

Common causes of P1933

Pump circuit shorted to ground
Failed pump pulling the line low
Chafed harness
Corroded connector
Module fault

How to fix P1933

Test for shorts to ground
Isolate the pump
Inspect harness routing
Clean the connector
Repair or replace per findings