GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC P0230: Fuel Pump Relay Control Circuit

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Fuel Pump Relay Coil Ignition Voltage

P0230

P0230

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Fuel Pump Relay Control

P0230

P0230

P0230

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Circuit/System Description

The engine control module (ECM) provides a ground to the coil side of the fuel pump relay. When the ignition switch is first turned ON, the ECM energizes the fuel pump relay, which applies power to the fuel pump. The ECM enables the fuel pump relay as long as the engine is cranking or running, and crankshaft reference pulses are detected. If no crankshaft reference pulses are detected, the ECM turns OFF the fuel pump relay after about 3 seconds.

Conditions for Running the DTC

    • The engine is operating.
    • The ignition voltage is between 11-18 volts.
    • DTC P0230 runs continuously when the above conditions are met.

Conditions for Setting the DTC

The ECM detects that the commanded state of the driver and the actual state of the control circuit do not match for greater than 2 seconds.

Action Taken When the DTC Sets

DTC P0230 is a Type B DTC.

Conditions for Clearing the MIL/DTC

DTC P0230 is a Type B DTC.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Fuel System Description

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

  1. Ignition ON, command the fuel pump relay ON and OFF with a scan tool. You should hear the relay click when commanded ON and OFF.
  2. Ignition ON, command the fuel pump relay ON and OFF with a scan tool while observing the following control circuit status parameters:
  3. • Fuel Pump Relay Ckt Short Gnd Test Status
    • Fuel Pump Relay Ckt Open Test Status
    • Fuel Pump Relay Ckt Short Volts Test Status
    • Each parameter should display OK or Not Run.
  4. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

  1. Ignition OFF, disconnect the fuel pump relay.
  2. Verify a test lamp illuminates between the relay ground circuit terminal 85 and B+.
  3. If the test lamp does not illuminate, repair the ground circuit for an open/high resistance.
  4. Ignition ON, test for 2-3 V between the control circuit terminal 86 and ground.
  5. If less than the specified range, test the control circuit for a short to ground, or an open/high resistance. If the circuit tests normal, replace the ECM.
    If greater than the specified range, test the control circuit for a short to voltage. If the circuit/connections test normal, replace the ECM.
  6. Command the fuel pump ON with a scan tool. The DMM should transition from 2-3 V when commanded OFF to greater than 10 V when commanded ON.
  7. If the circuit voltage does not correspond to the specified values, replace the ECM.
  8. If all circuits test normal, test or replace the fuel pump relay.

Component Testing

  1. Ignition OFF, disconnect the fuel pump relay.
  2. Test for 70-110 Ω between terminals 85 and 86.
  3. If not within the specified range, replace the relay.
  4. Test for infinite resistance between the following terminals:
  5. • 30 and 86
    • 30 and 87
    • 30 and 85
    • 85 and 87
         ⇒If not the specified value, replace the relay.
  6. Install a 20 A fused jumper wire between relay terminal 86 and 12 V. Install a jumper wire between relay terminal 85 and ground. Test for less than 2 Ω between terminals 30 and 87.
  7. If greater than the specified range, replace the relay.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Relay Replacement
    •  Control Module References for ECM replacement, setup, and programming