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, starts but does not run

²Starts but does not run

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

    • Ignition ON.
    • The system voltage is between 11-18 volts.
    • Engine speed is more than 0 RPM.
    • 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.
    • It occurs 8 times during the 10 tests.
    • DTC P0230 is set when the above conditions are met.

Action Taken When the DTC Sets

DTC P0230 is a Type B DTC.

Conditions for Clearing the DTC

DTC P0230 is a Type B DTC.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

    •  Engine Controls Connector End Views
    •  Engine Control Module Connector End Views

Electrical Information Reference

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

DTC Type Reference

Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

    •  Scan Tool Data List
    •  Scan Tool Data Definitions
    •  Engine Control Module Scan Tool Information

Special Tools

J 43244 Relay Puller Pliers

Circuit/System Verification

Ignition ON, command the fuel pump relay ON and OFF with a scan tool output. Listen/ feel for the relay to click and for the fuel pump to turn ON and OFF.

Circuit/System Testing

  1. Ignition OFF, disconnect the fuel pump relay.
  2. Test for less than 5 ohms between the ground circuit and ground.
  3. If more than the specified range, test the ground circuit for an open/high resistance.
  4. Connect a test lamp between the control circuit and the ground circuit of the fuel pump relay.
  5. Command the fuel pump relay ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
  6. If the test lamp remains illuminates, test the control circuit for a short to voltage. If the circuit test normal, replace the ECM.
    If test lamp remains OFF, test the control circuit for a short to ground, or an open or high resistance. If the circuit test normal, replace the ECM.
  7. 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 ohms between terminals 85 and 86.
  3. If not within the specified range, replace the relay.
  4. Test the following terminals for infinite resistance:
  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-amp fused jumper wire between relay terminal 85 and 12 volts. Install a jumper wire between relay terminal 86 and ground. Test for less than 2 ohms 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.

Control Module References for ECM replacement, setup, and programming