Evaporative Emission System Vent Control Circuit Shorted Low
There's a short circuit in the vent control for the evaporative emission system.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The computer sees that the vent control for the fuel tank isn’t functioning right, almost like it's stuck telling the system that it's always open when it shouldn't be.
What the computer is actually seeing
The ECM monitors the voltage at the vent control circuit. It should typically see around 12V when the circuit is active, but it’s reading close to 0V, indicating a short circuit.
What a healthy reading looks like
The vent solenoid should operate with a resistance of about 20-60 ohms, and the voltage should be near battery level (12V) when activated.
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 11. Inspect the wiring and connectors to the vent valve for damage or corrosion. If found, repair or replace them. Decision: If wiring/connectors are good, proceed to step 2. If damaged, repair/replace and retest.
- 22. Check the resistance of the vent valve. Disconnect the valve and measure resistance. Expected range: 20-60 ohms. Decision: If out of range, replace the vent valve. If within range, proceed to step 3.
- 33. Use a scan tool to command the vent valve ON and OFF. Check voltage at the valve connector. Expected voltage: ~12V when ON. Decision: If voltage is present, but valve doesn't operate, replace the vent valve. If no voltage, investigate ECM or harness.
Common causes
- Wiring harness damage between ECM and vent valve
- Faulty vent valve
- Connector issues at the vent valve or the ECM
- Moisture intrusion causing corrosion in connectors
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's drivable, but the vehicle may have increased emissions.
Will this code come back after clearing?
If the issue isn't resolved, yes, it will likely return.
Does this code pair with other codes?
Yes, codes like SPN 4424 and SPN 4425 can show up with it, indicating related issues in the evaporative system.
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