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 Descriptors

DTC P0458: Evaporative Emission (EVAP) Purge Solenoid Control Circuit Open
DTC P0459: Evaporative Emission (EVAP) Purge Solenoid Control Circuit Shorted

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Ignition 1 Voltage | * | P0458 | -- | --
EVAP Canister Purge Valve Control Circuit | P0458 | P0458 | P0459 | --
* Engine cranks but does not run and the fuse for the ignition 1 circuit opens.

### Circuit/System Description

The evaporative emission (EVAP) canister purge valve is used to purge fuel vapor from the EVAP canister to the intake manifold. The EVAP canister purge valve is pulse width modulated (PWM). Ignition voltage is supplied directly to the EVAP canister purge valve. The engine control module (ECM) controls the solenoid by grounding the control circuit with a solid state device called a driver. The driver is equipped with a feedback circuit that is pulled-up to a voltage. 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 engine is running.

• | The ignition voltage is between 11-16 volts.

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

### Conditions for Setting the DTC

#### P0458

The ECM detects the EVAP purge solenoid control circuit is open or shorted to ground.

#### P0459

The ECM detects the EVAP purge solenoid control circuit is shorted to voltage.

### Action Taken When the DTC Sets

DTC P0458 and P0459 are Type B DTCs.

### Conditions for Clearing the DTC

DTC P0458 and P0459 are Type B DTCs.

### Reference Information

#### Schematic Reference

Engine Controls Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Evaporative Emission Control 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 for scan tool information

### Circuit/System Verification

1. Engine running, command the EVAP Purge Solenoid to 100 percent, and back to 0 percent with a scan tool. The EVAP Purge Solenoid should respond to the scan tool commands.
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 harness connector at the EVAP purge solenoid.
2. Ignition ON, verify a test lamp illuminates between the ignition 1 voltage circuit terminal 2 and ground.

⇒ | If the test lamp does not illuminate, test the ignition 1 voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition 1 voltage circuit fuse is open, test all components connected to the ignition 1 voltage circuit and replace as necessary.

3. Ignition OFF, connect a test lamp between the control circuit terminal 1 and the ignition 1 voltage terminal 2.
4. Ignition ON, command the EVAP Purge Solenoid to 100 percent, and back to 0 percent with a scan tool. The test lamp should respond to the commanded state.

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

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

5. If all circuits test normal, test or replace the EVAP purge solenoid.

### Component Testing

1. Ignition OFF, disconnect the harness connector at the EVAP purge solenoid.
2. Test for 18-28 ohms of resistance between the ignition 1 voltage terminal 2 and the control terminal 1.

⇒ | If not within the specified range, replace the EVAP purge solenoid.

3. Test for infinite resistance between each terminal and the EVAP purge solenoid housing.

⇒ | If not the specified value, replace the EVAP purge solenoid.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Evaporative Emission Canister Purge Solenoid Valve Replacement

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