For 1990-2009 cars

### 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 | P0230 | --
Fuel Pump Ground | -- | ² | -- | --
¹Open fuel pump fuse, cranks no start ²Cranks no start ³Fuel pump operates continuously, then discharged 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 is ON.

• | The system 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 DTCs.

### Conditions for Clearing the MIL/DTC

DTC P0230 is a Type B DTCs.

### Reference Information

#### Schematic Reference

Engine Controls Schematics

#### Connector End View Reference

• | Engine Control Module Connector End Views

• | Engine Controls Connector End Views

• | Electrical Center Identification Views

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

• | Scan Tool Data List

• | Scan Tool Data Definitions

• | Scan Tool Output Controls

#### Special Tools Required

J 43244 Relay Puller Pliers

### Circuit/System Verification

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

### Circuit/System Testing

1. Ignition OFF, remove the fuel pump relay from the underhood electrical center.
2. Connect a test lamp between the control circuit and a good ground.
3. Command the fuel pump relay ON and OFF with a scan tool. The test lamp should turn ON and OFF with each command.

⇒ | If the test lamp is always OFF, test the control circuit for an open/high resistance or a short to ground. If the circuit tests normal, replace the ECM.

⇒ | If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the ECM.

4. Connect a test lamp between the control circuit and the ground circuit of the fuel pump relay. Command the fuel pump relay ON and OFF with a scan tool.

⇒ | If the test lamp is always OFF, repair the open/high resistance in the ground circuit of the fuel pump relay.

⇒ | If the test lamp does turn ON and OFF, test for an intermittent and for a poor connection at the fuel pump relay, or a faulty fuel pump relay.

### Component Testing

1. Measure for 70-110 ohms of resistance between terminals 85 and 86 of the fuel pump relay.

⇒ | If the resistance is not within the specified range, replace the fuel pump relay.

2. Measure for infinite resistance between the following terminals of the fuel pump relay:

• | 30 and 86

• | 30 and 87

• | 30 and 85

• | 85 and 87

⇒ | If continuity is detected, replace the fuel pump relay.

3. Connect a 15-amp fused jumper wire from the positive terminal of the battery to relay terminal 85. Connect a jumper wire from the negative terminal of the battery to relay terminal 86. Measure for less than 2 ohms between terminals 30 and 87 of the relay.

⇒ | If the resistance measures more than 2 ohms, replace the fuel pump relay.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Control Module References for ECM replacement, setup, and programming

• | Relay Replacement