Powertrain, generic (extended)

P2C04 Fuel Pressure Regulator D Control Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2C04 covers the opposite electrical fault to P2C03: the switched ground end of the regulator D circuit is connected to battery voltage. In GM's 23OBDG07 and 24OBDG07 tables the circuit belongs to the second fuel quantity control valve, counterpart of P0092 on the first. The ECM detects it while the driver is switched on: the line should then be pulled down, and if the voltage stays high, the module assumes a short of less than 0.5 ohm to the injector supply. Enable conditions are supply above 10.9 V and engine speed above 80 rpm; 20 failed events set the code on the first trip. As long as the short exists the valve cannot be switched, so pump output for that circuit is lost. Look for insulation damage where the harness runs near hot or moving parts, and for moisture in the connector.

Likely causes

Low-side wire shorted to a supply voltage
Moisture or corrosion bridging pins in the valve connector
Faulty output stage in the engine control module

Symptoms

  • Check engine light on
  • Reduced power, possibly limp mode
  • Engine may hesitate under load

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€60–1,200
Time0.5–3 h

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

Parts involved

fuel pressure regulator dhigh pressure fuel pumpwiring harness

Related codes

P2C02P2C03P0092P233C

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