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 P062A 00: Fuel Pump Relay Control Circuit Open

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Relay Coil Control | P0628 00, P062A 00 | P0627 00 | P0629 00 | --
Relay Coil Ground | -- | -- | -- | --

### Circuit/System Description

The engine control module (ECM) provides ignition voltage to the coil side of the fuel pump relay whenever the engine is cranking or running. The ECM enables the fuel pump relay as long as the engine is cranking or running, and ignition system reference pulses are received. If no ignition system reference pulses are received, the ECM turns OFF the fuel pump. The fuel pump relay control circuit is equipped with a feedback circuit that is pulled up to voltage within the ECM. The ECM can determine if the control circuit is open, shorted to ground, or shorted to a voltage by monitoring the feedback voltage.

### Conditions for Running the DTC

• | The ignition is ON or the engine is running.

• | The power stage is active.

• | The DTCs run continuously once the above conditions are met.

### Conditions for Setting the DTC

The ECM detects that the fuel pump relay control circuit temperature is too high for greater than 1 s.

### Action Taken When the DTC Sets

DTC P062A is a Type A DTC.

### Conditions for Clearing the DTC

DTC P062A is a Type A 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

1. Ignition ON, command the Fuel Pump Relay ON and OFF with a scan tool. You should hear and feel an audible click.
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. Test for less than 5 Ω between the ground circuit terminal 9 X3 and ground

⇒ | If greater than the specified range, test the ground circuit for an open/high resistance

3. Connect a test lamp between the control circuit terminal 13 X3 and ground.
4. Ignition ON, 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.

⇒ | If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the K20 Engine Control Module (ECM).

⇒ | If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module (ECM).

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

### Component Testing

1. Ignition OFF, disconnect the fuel pump relay.
2. Test for 70-110 Ω of resistance between terminals 85 and 86.

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

3. Test for infinite resistance between the following terminals:

• | 30 and 86

• | 30 and 87

• | 30 and 85

• | 85 and 87

⇒ | If not the specified value, replace the KR23A Fuel Pump Relay.

4. Install a 20 A fused jumper wire between relay terminal 85 and B+. Install a jumper wire between relay terminal 86 and ground. Test for less than 2 Ω between terminals 30 and 87.

⇒ | If greater than the specified range, replace the KR23A Fuel Pump Relay.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for ECM replacement, setup, and programming