What Are The Common Causes Of P0498 Honda Accord Error?

The P0498 Honda Accord trouble code usually signifies a problem with the vent shut valve in the evaporative emission control (EVAP) system. This system is responsible for preventing fuel vapors from escaping the fuel system and entering the atmosphere.

The vent shut valve (VSV) seals off the EVAP canister, where fuel vapors accumulate from the outside air. When closed, it forces evaporated fuel to be purged into the engine and burned off. If it fails to operate properly, you’ll get the P0498 Honda Accord code.

While a faulty VSV is most common, the P0498 Honda Accord can also be caused by wiring issues, PCM faults, or other EVAP component failures. Let’s look at the most likely culprits.

Table of Contents

Common Causes Of P0498 In Honda Accord

Here are the most common reasons you’ll see P0498 Honda Accord:

  1. Faulty Vent Shut Valve
  2. EVAP System Leaks
  3. Circuit Wiring Issues
  4. PCM Failure

Faulty Vent Shut Valve

The vent shut valve is essentially a solenoid-controlled gate between the EVAP canister and outside air. If it fails to operate when commanded, you’ll get the P0498 Honda Accord code.

On Honda Accord models, the VSV is prone to failure and must be replaced when diagnosed as faulty. Fuel residue, cracks, damage, or corrosion can prevent the vent from operating normally.

EVAP System Leaks

Leaks in EVAP hoses, the canister, or other components allow fuel vapor to escape the system. This trips the P0498 Honda Accord code.

Inspect all EVAP plumbing for cracks, damage, or disconnects. The canister should be checked for cracks or holes, too.

Circuit Wiring Issues

Problems with the wiring between the PCM and the vent shut valve can cause the P0498 Honda Accord. Shorts, high resistance, opens, and poor connections can affect the circuit.

Carefully inspect wiring and connectors for corrosion, damage, etc. Check for continuity and resistance on circuits.

Common Causes Of P0498 In Honda Accord
Common Causes Of P0498 In Honda Accord

PCM Failure

In rare cases, a PCM failure leads to improper vent valve operation and P0498 Honda Accord. But this is very unlikely unless you have other PCM-related faults too.

Symptoms Of P0498 Honda Accord

The P0498 Honda Accord might not produce any noticeable symptoms by itself. But here are a few things that may occur:

  1. Slightly increased fuel consumption
  2. A small decrease in engine performance
  3. Mildew or musty smells from EVAP leaks
  4. Check Engine Light illumination

Most of the time, the only sign of the issue will be the stored P0498 Honda Accord code.

How To Diagnose P0498 Honda Accord?

Pinpointing the root cause requires proper diagnostic testing. Here is the general process for troubleshooting P0498 Honda Accord:

Read and Clear Codes

Use a scan tool to read engine codes. Look for the P0498 Honda Accord and any other related EVAP codes that may be present. Clear all codes once noted.

Inspect for Leaks, Damage, and Corrosion

Check under the hood for obvious leaks in the EVAP system hoses and components. Look for any damage, loose connections, or corrosion as well.

Check Wiring

Inspect wiring and connectors in the vent shut valve control circuit. Perform resistance and continuity tests on wires. Check for shorts to power/ground.

Vent Shut Valve Testing

With the valve disconnected, use a DVOM to check its coil resistance. Refer to factory specs. Also verify the valve opens and closes when commanded via the scan tool.

Additional EVAP System Testing

Further, pinpoint EVAP leaks using smoke testing or tank pressure testing if needed. Follow factory service procedures.

Testing the valve, circuitry, and EVAP system helps narrow down the P0498 Honda Accord cause.

Fixing P0498 In Honda Accord

Once properly diagnosed, P0498 Honda Accord can be repaired with one or more of these procedures:

  1. Replace Faulty Vent Shut Valve
  2. Repair Wiring & Connectors
  3. Fix Leaks
  4. Inspect PCM

Replace Faulty Vent Shut Valve

If valve resistance is out of spec or it fails to operate when energized, replace it. This applies the 12V power to open/close it. Be sure to clear codes after replacement to see if it fixed the P0498 Honda Accord.

P0498 Honda Accord
P0498 Honda Accord

Repair Wiring & Connectors

Any wiring faults found during diagnosis need to be repaired. Splice or solder damaged wires. Fix corroded or loose connectors. Clear codes afterward and confirm the operation.

Fix Leaks

Replace any leaking EVAP hoses, gaskets, or other components. Use Honda-approved parts to maintain a sealed system. Retest after repairs.

Inspect PCM

If no other fixes resolve the P0498 Honda Accord, the PCM itself may be faulty. Try reflashing the ECU to update it before replacing the PCM module outright.

With the proper troubleshooting and repairs, the P0498 Honda Accord can be eliminated for good.

Also Read:


Does P0498 Disable The Vehicle?

No, P0498 Honda Accord is considered a non-critical emission related fault. It will illuminate the Check Engine light but won’t disable the vehicle or prevent it from operating normally in most cases.

How Much Does It Cost To Fix The P0498 Honda Accord?

Repair costs vary depending on the cause but typically run $150-$350 in total parts/labor to resolve P0498 Honda Accord. Vent shut valve replacement and wiring repairs make up most of these expenses. Proper diagnosis is key to an economical repair.

Is It Safe To Drive With A P0498 Honda Accord?

Yes, the P0498 Honda Accord alone won’t make the vehicle unsafe to drive. No critical engine or drivetrain functions are affected. However, the underlying issues that caused it should be diagnosed and repaired promptly. Driving long-term with EVAP faults could lead to check engine light troubles or failed emissions testing down the road.

Can P0498 Return After Being Deleted?

It’s possible for the P0498 Honda Accord to come back after clearing if the underlying condition wasn’t properly repaired. Erasing the code alone without diagnostic testing won’t resolve the root cause. Any leaks, wiring faults, or defective parts must be addressed to avoid it returning.


P0498 Honda Accord is a common trouble code related to the EVAP vent shut valve on Accord models. While not inherently dangerous, it points to an issue in the evaporative emissions controls that should be addressed promptly.

Faulty vent valves, leaks, wiring faults, and PCM problems are the main causes, with the vent valve being the most common. Accurate diagnostics of the valve, circuitry, and overall EVAP system are needed to pinpoint the root cause of your particular vehicle. From there, valve replacement, leak repairs, wire repairs, or PCM updates can clear the P0498 Honda Accord for good.

Author's Image

Ammar Masoud

I have had a long and fulfilling career in the automotive industry, primarily with Honda and Acura. With 15 years of experience as a Honda service technician, I became highly skilled in repair and maintenance, gaining a deep understanding of these vehicles. After many years in the automotive field, I decided to embark on a second career in industrial manufacturing. It was a significant change, but I found that the skills I had honed in the automotive industry were incredibly valuable in my new role. In my current position in industrial manufacturing, the demand for quality workmanship and meticulous attention to detail is paramount. Fortunately, these are traits that I have cultivated throughout my years in the automotive industry. I take pride in applying these skills to meet the high standards expected in the manufacturing sector.