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

Battery Voltage - Relay Switch Side

¹

²

--

--

Fuel Pump Supply Voltage

¹

²

³

--

Fuel Pump Relay Control

P0230

P0230

P0230

--

Fuel Pump Relay Ground

--

P0230

--

--

Fuel Pump Ground

--

²

--

--

¹Open fuel pump fuse, cranks no start

²Cranks no start

³Fuel pump operates continuously, then discharges battery

Circuit/System Description

The control module enables the fuel pump relay when the ignition switch is turned ON. The control module will disable the fuel pump relay within 2 seconds unless the control module detects ignition reference pulses. The control module continues to enable the fuel pump relay as long as ignition reference pulses are detected. The control module disables the fuel pump relay within 2 seconds if ignition reference pulses cease to be detected and the ignition remains ON.

The control module monitors the voltage on the fuel pump relay control circuit. If the control module detects an incorrect voltage on the fuel pump relay control circuit, a fuel pump relay control DTC sets.

Conditions for Running the DTC

    • The ignition voltage is between 9-18 volts.
    • DTC P0230 runs continuously when the above conditions are met.

Conditions for Setting the DTC

    • The control module detects that the commanded state of the driver and the actual state of the control circuit do not match.
    • The above condition is met for a minimum of 2.5 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

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

Important: An open or a short to voltage in the control circuit will cause both the Ckt. Open Test Status and the Ckt. Short Volts Test Status parameters to display Fault.

Ignition ON, command the fuel pump relay ON and OFF with a scan tool while observing the following control circuit status parameters:

    • 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 toggle between OK and Not Run or Not Run and OK.

Circuit/System Testing

  1. Ignition OFF, disconnect the fuel pump relay.
  2. Ignition ON, verify that a test lamp illuminates between the ground circuit terminal and B+.
  3. If the test lamp does not illuminate, test the ground circuit for a short to voltage or an open/high resistance.
  4. Verify that a test lamp does not illuminate between the ground circuit terminal and the control circuit terminal.
  5. If the test lamp illuminates, test the control circuit for a short to voltage. If the circuit tests normal, replace the ECM.
  6. Remove the test lamp.
  7. Command the fuel pump relay ON with a scan tool. Verify the scan tool fuel pump relay Ckt. Short Grnd Test Status parameter is OK.
  8. If not the specified value, test the fuel pump relay control circuit for a short to ground. If the circuit tests normal, replace the ECM.
  9. Install a 3A fused jumper wire between the fuel pump relay control circuit terminal and the ground circuit terminal. Command the fuel pump ON with a scan tool. Verify the scan tool fuel pump relay Ckt. Short Grnd Test Status parameter is Fault.
  10. If not the specified value, test the fuel pump relay control circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
  11. If all circuits test normal, test or replace the fuel pump relay.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

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