Powertrain, generic · Fuel and air metering (injector circuit)

P023F Fuel Pump Secondary Circuit/Open

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

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.

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

Symptoms

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

Repair estimate

DifficultyMediumDIY possible
Parts and labour€30–900
Time0.5–3.5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

fuel pumpfuel pump control modulefuel pump wiring

Related codes

P0230P0231P0232P0233P2635P0627

References: law.cornell.edu, gsi.ext.gm.com, gsi.ext.gm.com, saabwisonline.com.