P2403 Evaporative Emission System Leak Detection Pump Sense Circuit/Open
P2403 is a generic OBD2 powertrain code. It means “Evaporative Emission System Leak Detection Pump Sense Circuit/Open” — the same on every make and model, because the definition comes from the SAE J2012 standard rather than from the carmaker.
Ask the AI about P2403 on your car- System
- Powertrain (P)
- Code type
- Generic (SAE)
- Range
- P24xx
What the wording tells you
“Open” means the module found a break in the circuit — no current flowing where there should be. Check the connector (unplugged, corroded, a pushed-back pin), the wire, the fuse and the component’s own coil or element.
Can I keep driving with P2403?
The rule of thumb for this area (auxiliary emission controls): Most codes here don’t change how the car drives — you can keep going and fix it before the next emissions test. The exceptions are the cooling-fan codes (watch the temperature gauge), particulate-filter codes on diesels, and anything that comes with a flashing lamp or a rotten-egg smell.
How P2403 breaks down
Powertrain. Engine, transmission, fuel and emissions — the codes behind the check engine lamp.
Generic code: defined by SAE, the same on every make.
Auxiliary emission controls.
The specific fault within this range.
Where to look: Auxiliary emission controls
The systems that clean up exhaust and fuel vapor: exhaust gas recirculation (EGR), secondary air injection, catalytic converter monitoring, the evaporative emissions (EVAP) system with its purge and vent valves — plus exhaust temperature sensors, the particulate filter and some cooling-fan circuits.
Typical causes in this area
- A loose or faulty gas cap and other EVAP leaks
- Carbon-clogged EGR valves and passages
- Worn catalytic converters or lazy oxygen sensors
- Stuck purge and vent valves
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Read and clear P2403 on your iPhone
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Frequently asked
What does P2403 mean?
P2403 is a generic OBD2 powertrain code. It means “Evaporative Emission System Leak Detection Pump Sense Circuit/Open” — the same on every make and model, because the definition comes from the SAE J2012 standard rather than from the carmaker.
Can I drive with P2403?
The rule of thumb for this area (auxiliary emission controls): Most codes here don’t change how the car drives — you can keep going and fix it before the next emissions test. The exceptions are the cooling-fan codes (watch the temperature gauge), particulate-filter codes on diesels, and anything that comes with a flashing lamp or a rotten-egg smell.
What causes P2403?
“Open” means the module found a break in the circuit — no current flowing where there should be. Check the connector (unplugged, corroded, a pushed-back pin), the wire, the fuse and the component’s own coil or element. Typical causes in this area: A loose or faulty gas cap and other EVAP leaks; Carbon-clogged EGR valves and passages; Worn catalytic converters or lazy oxygen sensors; Stuck purge and vent valves.
How do I clear P2403?
Fix the cause first, then clear it with any OBD2 scanner or app. Once the fault is gone the car also clears it on its own: the check engine lamp goes off after the self-test passes on three drive cycles in a row, and the stored code ages out after about 40 warm-ups. Clearing without a repair only hides it for a while — and resets the readiness monitors an emissions inspection looks at.
Is P2403 the same on every car?
Yes. P2403 is a generic SAE J2012 code, so its definition is identical on every make and model. What differs is the cause behind it and the repair procedure, which depend on the engine — that’s why the assistant on this page asks for your car.
Guides
Definitions: the generic SAE J2012 codes from Brimly’s offline dictionary (data version 2026.09). Causes and advice are general guidance for all makes — the service information for your car has the last word.