P023F: Fuel Pump Secondary Circuit/Open

The fuel pump circuit has two sides: the primary circuit is the engine module's output to the fuel pump relay coil (or to a pump control module), the secondary circuit is the power circuit from relay contact or module to the pump itself. P023F means the power circuit to the pump is open. GM pumps with their own power module, whose speed is controlled by rail pressure, measure the pump current: if it stays below 1 A (older modules 0.5 A) although the pump is commanded, the code sets with the warning light in the first trip, and fuel pressure diagnostics are suspended. The cause lies in the wire from module to pump or its return, the pump connector or the pump motor itself. The pump stops, so the engine will not start or dies – there is no limp mode.

Symptoms

• Engine does not start, no pump noise
• Engine stalls while driving
• Check engine light on

Most likely causes

• Pump connector at tank flange or pump module open or corroded
• Fuel pump open internally (brushes, winding)
• Wire from module to pump or return wire open
• Pump control module faulty

What to check, in order

Start with the simplest. You can tick off each step.

1. Check the pump's fuse, relay, and connector
2. Check the continuity of the wire between the component and the control module.
3. Replace the filter if it is due for maintenance
4. Compare commanded and actual pressure in live data
5. Measure the pressure with a suitable gauge
6. Check the sensor and regulator before replacing the pump

Good to know

• Repair difficulty: medium
• It affects emissions.

What each character of P023F means

• P: Powertrain: engine and transmission
• 0: Generic code: same on every make
• 2: Fuel injection
• 3F: Specific fault in that system

Frequently asked questions

Can I keep driving with code P023F?

Avoid long trips and hard acceleration. If you smell fuel or the car stalls, do not continue.

What causes code P023F?

The most common causes are: pump connector at tank flange or pump module open or corroded; fuel pump open internally (brushes, winding); wire from module to pump or return wire open.

Related codes

• P0230Fuel Pump Primary Circuit
• P0231Fuel Pump Secondary Circuit Low
• P0232Fuel Pump Secondary Circuit High
• P0233Fuel Pump Secondary Circuit Intermittent
• P2635Fuel Pump A Low Flow/Performance
• P0627Fuel Pump A Control Circuit/Open

Sources

• law.cornell.edu: 13 CCR 1968.2
• gsi.ext.gm.com: 18OBDG03A Engine Diagnostics
• gsi.ext.gm.com: 16OBDG06 Engine Diagnostics
• saabwisonline.com: dtc p0231 p0232 or p023f

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.