Code Definition

P0628 — Fuel pump power (monitoring) circuit low - circuit A

System: Powertrain  |  Type: Generic (OBD-II Standard)  |  Make: Generic

About P0628

P0628 is a generic (obd-ii standard) powertrain diagnostic trouble code. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

When P0628 is stored, the module has detected a signal or supply voltage lower than the expected operating range.

Scanning & clearing: A generic OBD-II scan tool will usually read and clear powertrain (P) codes. For live data, freeze-frame capture, and bi-directional tests you may need a more capable scan tool that supports the vehicle's ECM protocol.

Because P0628 is a generic OBD-II code, its base definition is shared across manufacturers. The specific diagnostic steps, reference values, and repair procedures can vary by vehicle, and the TaT Diagnostic Assistant includes verified procedures submitted by working technicians.

Code Information

The P0628 fault code is triggered when the Engine Control Module (ECM) or Powertrain Control Module (PCM) detects a low voltage condition in the fuel pump power monitoring circuit, specifically in circuit A. This circuit monitors the voltage being supplied to the fuel pump to ensure it is within the specified range for proper pump operation. A low voltage condition in this monitoring circuit may indicate insufficient power being supplied to the fuel pump, which could affect fuel delivery and engine performance.

Quick Facts