What is the P0458 fault code and why does it matter? What causes the Evaporative Emission System purge Control Valve Circuit Circuit Low malfunction? How can you fix P0458 fault code What are the causes and symptoms for the P0458 fault code
What is the P0458 fault code? What does it mean
P0458 is a code that indicates that a part of the EVAP System purge control valve circuit has failed, causing a voltage reading not in accordance with the manufacturer’s specifications.
The evaporative emissions control system (EVAP), whose task it is to stop the release unburned fuel vapors in the atmosphere, has its primary purpose. Its purpose is to reduce vehicle emissions. Although design features can vary, the majority of systems include the fuel tank, fuel cap and vacuum lines, canister and relief valves, pressure and flow sensors, various control solenoids/valves and fuse, relay, electrical wiring and connectors. Some applications may not require all these components, or contain different components.
The vent valve and canister are closed when the engine is turned off. This prevents fuel vapors from escaping into atmosphere by storing them in the canister. The relief valve opens, and the fuel vapours from the canister are pulled into the intake funnel. The vent valve also opens, allowing air to pass through the canister and mix with fuel vapors. The system pressure is measured using a sensor, and then sent as a voltage to the powertrain controller module (PCM). The PCM will close the valves again if fuel vapors are sent directly to the engine. If system pressure falls, the sensor sends a voltage signal to the powertrain control module (PCM). Fuel vapors are not sent to the engine if fuel demand rises or if the vapor pressure in EVAP exceeds predetermined levels.
The PCM continuously monitors the drain valve circuit and its circuit. The code P0458 is set if the PCM detects lower than expected voltage signals from the drain valve circuit.
P0458 fault codes can be found on vehicles made by Subaru, Mini Volvo and Ford.
What is the P0458 Fault Code?
These are the most common reasons that P0458 fault codes are triggered:
- – Missing or damaged fuel filler cap
- Canister canisters that are broken, clogged, or deficient
- – Defective purge control solenoid/valve
- – Defective pressure/flow sensor
- – Damaged or melted cables and/or connectors
- – Defective vacuum hoses
- – Defective fuel vapor hoses
- – A blown fuse, or faulty relay
- – Defective PCM
What are the symptoms of the P0458 Malfunction code?
These symptoms may be present in vehicles with code P0458.
- – Illumination for the check engine light
- – EVAP is not working
- If the relief valve is left open, the engine’s idle quality can deteriorate. The engine might run unevenly at certain throttle settings or stall unexpectedly.
- – A slight increase in fuel consumption
- If the canister becomes clogged, excess pressure could build up. A “puffing sound” may be heard when you open the fuel tank cap.
- If the vehicle is left in direct sunlight for long periods of time or if the vacuum hoses become dislodged, it may emit a strong fuel smell.
- – Setting related fault codes
How do I fix the P0458 fault code?
When diagnosing code P0458, the most common error is to replace component parts without first checking for leaks or improper installation. Before replacing system components, a thorough diagnostic must be done.
Here are some of the possible repairs that could resolve the P0458 fault codes:
- – Replacement or correction of a damaged fuel cap
- – Repair or Replace all damaged wiring and connectors to system components and circuits
- – Replacing a defective purge control solenoid/valve
- – Clean or replace a faulty, clogged, or broken canister canister
- – Replacing defective vacuum hoses
- – Replacing faulty fuel vapor hoses
- – Check the flow/pressure sensor and replace it if necessary
- – Replacing a faulty relay or fuse
The code must be removed from the PCM after each repair and the system must then be retested. This will reduce the possibility of code errors and make it easier to locate the source.
How serious is the P0458 Fault code?
P0458 by itself is not a problem. This code is usually associated with the EVAP system. You should immediately fix any problems with the vehicle’s pressure system. The EVAP system is primarily designed to reduce vehicle emissions. Failing to install an EVAP system can cause your vehicle to be less environmentally-friendly, and you may have your emissions test fail.
