Fuel Pump Speed Control Circuit Malfunction
Findings, check these first
- Open or shorted speed control circuit
- Failed speed controller
- Failing pump not responding to speed commands
- Corroded connector
- PCM command fault
Standard procedure
- Command different pump speeds and verify response
- Test the speed control circuit
- Check pump current at each speed
- Inspect the connector
- Replace the controller or pump per response
Code lookup
Type a code above, or start from a symptom or a common code.
Press / to jump to the box. Ford-enhanced powertrain, body, chassis and network codes. Generic P0xxx codes live on OBD Codes List.
Sources and review
Review: checked against the recorded source material.
- OBDII.pro: P1644 Ford definition
live reference page (obdii.pro)
Supports: Ford-family meaning for P1644: Fuel Pump Speed Control Circuit Malfunction
Fetched directly. obdii.pro is a publisher independent of the engine-codes family.
- P1644 FORD Code: Meaning, Causes, and Symptoms | OBD2 Codes
live reference page (obd2-codes.co)
Supports: Ford meaning for P1644: Fuel Pump Speed Control Circuit Malfunction
Fetched directly. obd2-codes.co phrasing matches the engine-codes family, so it counts as one publisher.
Last updated 2026-09-06.
Report a correction for P1644. Include your vehicle, the issue and a source if you have one.
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