P0459
PowertrainEvap Systemlow severityEvaporative Emission System Vent Valve Control Circuit High
What P0459 Means
The PCM detected high voltage in the EVAP purge/vent valve control circuit. This typically indicates an open circuit or a short to power.
Symptoms
- Check engine light on
- EVAP purge not functioning
- Failed emissions test
Common Causes
- Open control circuit wiring
- Faulty EVAP purge/vent valve
- Short to power in circuit
- Poor connector contact
Diagnostic Steps
- Inspect valve connector and wiring
- Check for open in control circuit
- Test for short to voltage
- Replace valve if faulty
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