Diesel Trouble Codes

P0230 — Fuel Pump Primary Circuit (7.3 Power Stroke)

Fuel Pump Primary Circuit

Updated September 2, 2026

What it means

The engine control module has detected an electrical fault in the primary control circuit of the fuel pump. On the 7.3L Power Stroke (1999-2003 Super Duty/Excursion) this is the low-pressure supply side only; the engine uses HEUI injection with no high-pressure fuel pump or rail pressure. P0230 is low-pressure supply circuit only.1

Most likely causes

  1. Open or short in the fuel pump power/ground circuit or wiring harness — Inspect the wiring, connectors, and grounds for the frame- or tank-mounted electric supply pump. Look for chafing, corrosion, or loose terminals that interrupt the primary control circuit.1
  2. Faulty fuel pump relay or fuse — Check the relay and fuse that supply power to the low-pressure pump. A stuck or burned relay, or a blown fuse, will set a primary circuit fault.1
  3. PCM driver fault for the fuel pump circuit — If power and ground to the pump are correct but the PCM cannot energize the circuit, the PCM driver may be faulty. Verify control signals before condemning the PCM.1
  4. Fuel pump motor failure causing abnormal current draw — A seized or shorted pump motor can pull excessive current and trigger a primary circuit fault. Confirm pump operation and current draw with a test light/amp clamp.1

How to diagnose

  1. Verify code and freeze-frame data; confirm P0230 is present on a 1999-2003 7.3L Power Stroke.
  2. Check battery voltage and chassis grounds; poor grounds cause false circuit faults.
  3. Inspect fuel pump relay, fuse, and related wiring for damage, corrosion, or loose connections.
  4. Command the fuel pump on with a scan tool and listen/feel for pump operation; check voltage at the pump connector.
  5. Measure current draw of the pump; excessive draw indicates a failing pump motor.
  6. Inspect the fuel filter bowl wiring and water-in-fuel sensor harness for chafing that can affect pump circuit integrity.

Parts and tools you may need

Rough cost and difficulty

Parts and labor vary by region and whether the pump is frame-mounted or in-tank. Relay/fuse replacement is low cost; pump replacement is higher due to access and fuel system handling.

When to see a pro

If the PCM driver is suspected, or wiring faults are inside the harness, have a qualified diesel technician perform circuit testing and PCM evaluation. Do not attempt high-pressure fuel line work on this HEUI system.

Sources

  1. Curated DTC seed — 7.3 Power Stroke (curated) ↩︎ ↩︎ ↩︎ ↩︎ ↩︎