The evaporative emission (EVAP) control system traps volatile organic compounds (VOCs) and prevents HC emissions from escaping into the atmosphere. The system consists of a fuel tank filler cap with a built-in pressure-vacuum relief valve that lets fresh air circulate inside the entire structure. When the powertrain control module (PCM) detects an issue with the valve, it will log a code P0498.
What Does the P0498 Code Mean?
Diagnostic trouble code (DTC) P0498 stands for “Evaporative Emission System Vent Valve Control Circuit Low.”
Modern EVAP systems have a vent valve that opens whenever the pressure or vacuum exceeds a calibrated value and closes when the pressure or vacuum has been relieved.
When the PCM detects that the valve is venting when it should not, on-board diagnostics (OBD) will log a P0498 code.
Note: The definition of code P0498 might be different depending on the vehicle manufacturer. Consult the appropriate repair manual or repair database for the exact code definition.
What are the Common Causes of the P0498 Code?
- EVAP vent valve failure
- Wiring issues or a blown fuse
- Faulty PCM
What are the Common Symptoms of the P0498 Code?
- Illuminated check engine light
- Rough idling
- Stalling
How to Diagnose the P0498 Code
Diagnosing DTCs like the P0498 typically involves using a scan tool and conducting visual inspections to check for damaged vapor hoses that could create vacuum leaks. However, keep in mind that the steps for diagnosis and repair can vary, depending on your vehicle’s specifications.
If you’re not familiar with the process of diagnosing trouble codes and mapping out the EVAP system, it’s best to have a professional inspect your vehicle. Otherwise, you can go ahead and do the job yourself.
To help you out, here are a couple of videos that can give you an idea of what the process might involve.
How to Fix the P0498 Code
Attempting to fix a P0498 code can be confusing if you don’t have the right technical knowledge and tools. Under these circumstances, it’s best to leave the job to a certified mechanic to ensure that all steps and protocols are followed correctly.
But if you’re confident that you can address the code on your own, keep in mind that the steps for diagnosis and repair can vary from one vehicle to another. So before you proceed, make sure you’re equipped with the right guides and equipment.
Online auto repair resources like those from Chilton or an ALLDATA subscription contain vehicle-specific repair information, which will come in handy when fixing the P0498 code.
Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.
