Generic fault code

P0458 — EVAP system purge control valve A, circuit: signal low

The control unit stores code P0458 when it detects this fault: “EVAP system purge control valve A, circuit: signal low”.

Indicative severity: MediumEmission control

Reviewed by Daniel Morales, founder of Reprorace SL, on

What does code P0458 mean?

The catalytic converter, oxygen sensors, EGR, fuel vapor system (EVAP), particulate filter and NOx reduction clean the exhaust. A fault here raises pollution and may make the car fail its inspection; left alone, some end in a bigger fault or in limp-home mode.

System
P · Powertrain
Area
Emission control · Car system: Exhaust and emissions
Type
Generic (SAE J2012 / ISO 15031-6): the same meaning on every make
Indicative severity
Medium. Diagnose soon: it may raise emissions or consumption, or trigger limp-home mode.

What usually causes code P0458?

  1. Short circuit to ground
  2. Loose or corroded connector, backed-out terminals
  3. Damaged, chafed or pinched wiring

The most likely causes come first. Only a check on the car confirms which one is yours.

What are the symptoms of code P0458?

  • Usually nothing you notice while driving
  • Sometimes a smell of gasoline near the car
  • In some cases, trouble refueling

These are the usual symptoms of this kind of fault: not all of them always appear, and sometimes you notice nothing.

Can I keep driving with code P0458?

With care, and not for long. You can take the car to a workshop, ideally without long trips or heavy loads, and without putting it off: fuel use or emissions may rise and the car may go into limp-home mode (less power). If the light flashes, a red warning light comes on, the temperature rises or you notice a loss of power, noises or smoke, stop as soon as it is safe.

This is guidance only: only someone who checks the car can say whether it is safe to drive.

An indicative description of the code's generic meaning. Each manufacturer may give it a different meaning, conditions or tests: always follow its service information and your workshop's advice.

What you can do yourself

For this kind of fault

Check that the fuel cap closes properly, until it clicks, and that its seal is not damaged. Afterwards the light may take a few days of driving to go out.

  1. Read the code and keep the report: with an ECO-LITE in the OBD socket you see it on your phone or computer, with the data captured when the fault happened.

  2. Look for anything obvious: a loose connector, a disconnected hose, a fuel cap not closed properly or a low fluid level. Do not take apart anything you do not know.

  3. Clear the code only after writing it down or after the repair. Clearing turns the light off, but it also deletes the freeze-frame data and the readiness monitors used at the inspection.

  4. Drive normally for a few days and read the codes again. If the code comes back, the fault is still there: book the workshop and bring the report.

Read your car's fault codes on your phone

With an ECO-LITE in the OBD socket you see the codes in your account, with the data captured when the fault happened, and your workshop can check them remotely, always with your permission.

Related codes

  • P0453EVAP system pressure sensor/switch A, circuit: signal high
  • P0454EVAP system pressure sensor/switch A, circuit: intermittent
  • P0455EVAP system: large leak detected
  • P0456EVAP system: very small leak detected
  • P0457EVAP system: leak detected (fuel cap loose or missing)
  • P0459EVAP system purge control valve A, circuit: signal high

P04xx codes: auxiliary emission controls

All fault codes

In the glossary

Read more: Remote OBD diagnostics: what it is, how it works and what it can't do

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