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 provide an overview of each diagnostic category.

### DTC Descriptor

DTC P0230 00: 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 00 | P0230 00 | -- | --
Fuel Pump Relay Control | P0230 00 | P0230 00 | P0230 00 | --

### 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 s.

### Conditions for Running the DTC

• | The engine is operating

• | The ignition voltage is between 11 to 18 V.

• | The airflow into the engine is greater than 3 g/s.

• | The DTCs run continuously once 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 s.

### Action Taken When the DTC Sets

DTC P0230 00 is a Type C DTC.

### Conditions for Clearing the DTC

DTC P0230 00 is a Type C 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

### 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. 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 KR23A Fuel Pump Relay.
2. Ignition ON, verify that a test lamp illuminates between the KR23A Fuel Pump Relay coil ignition circuit terminal 85 and B+.

⇒ | If the test lamp does not illuminate, repair the ground circuit for an open/high resistance.

3. Ignition ON, test for 2-3 V between the KR23A Fuel Pump Relay control circuit terminal 86 and ground.

⇒ | If less than the specified range, test the KR23A Fuel Pump Relay control circuit for a short to ground, or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module (ECM).

⇒ | If greater than the specified range, test the control circuit for a short to voltage. If the circuit/connections test normal, replace the K20 Engine Control Module (ECM).

4. Command the Fuel Pump Relay ON with a scan tool. The DMM should transition from 2-3 V when commanded OFF to greater than 10 V when commanded ON.

⇒ | If the circuit voltage does not correspond to the specified values, replace the K20 Engine Control Module (ECM).

5. If all circuits test normal, test or replace the KR23A Fuel Pump Relay.

### Component Testing

#### Static Test

1. Ignition OFF, disconnect the KR23A Fuel Pump Relay.
2. Measure for 70-110 Ω between terminals 85 and 86 of the KR23A Fuel Pump Relay.

⇒ | If the resistance is not within the specified range, replace the KR23A Fuel Pump Relay.

3. Measure for infinite resistance between following terminals of the KR23A Fuel Pump Relay:

• | Terminals 30 and 86

• | Terminals 30 and 87

• | Terminals 30 and 85

• | Terminals 85 and 87

⇒ | If continuity is detected, replace the KR23A Fuel Pump Relay.

4. Connect a 20 A fused jumper wire from the positive terminal of the battery to the appropriate KR23A Fuel Pump Relay terminal 86 and B+. Connect a jumper wire from the negative terminal of the battery to KR23A Fuel Pump Relay terminal 85. Measure for less than 5 Ω between KR23A Fuel Pump Relay terminal 30 and terminal 87.

⇒ | If the resistance measures more than 5 Ω, replace the KR23A Fuel Pump Relay.

### Repair Instructions

Perform the Diagnostic Repair Verification

• | Relay Replacement

• | Control Module References