What this code means
P0498 may indicate low voltage in the EVAP canister vent shut valve circuit as seen by the ECM or PCM.
What the vehicle may do
- The vehicle may turn on the check engine light.
- It may have little or no noticeable drivability complaint.
- The EVAP monitor may not complete normally while the fault is present.
Possible fault areas
- Possible EVAP canister vent shut valve concern.
- Possible power feed concern to the valve.
- Possible control wire concern between the valve and PCM.
- Possible connector or terminal condition.
- Possible PCM software or PCM control concern.
Diagnostic path
Opening context
On this 2010 to 2016 Honda CR-V with the 2.4 gas engine, P0498 is for low voltage on the EVAP canister vent shut valve circuit. In plain terms, the ECM or PCM may not be seeing the vent shut valve control circuit behave the way it expects. The vehicle may have a check engine light with little or no drivability complaint, and the fault area can be the vent shut valve, its power feed, the control wire back to the PCM, connector or terminal condition, or in some cases PCM software or PCM control. Before getting into pinpoint checks, start with the basic system checks and make sure the general troubleshooting basics are handled.
Confirm whether P0498 is active
Start by turning the vehicle to the ON mode. Clear the DTC with the HDS, then check for Pending or Confirmed DTCs with the HDS. If P0498 comes right back, go straight into the circuit checks. If it does not come back, run the EVAP test through the inspection menu and command EVAP CVS ON in the single solenoid test with the HDS. Then check again for Pending or Confirmed DTCs. If P0498 sets during that test, the failure is duplicated and you continue with the circuit diagnosis. If it does not set, treat it as an intermittent at this time: check for poor connections or loose terminals at the EVAP canister vent shut valve, and if captured data is available, try to reproduce the same operating conditions.
Check the FI SUB RLY OUT feed
With the fault confirmed or duplicated, check the power side first. Turn the vehicle to the OFF (LOCK) mode and disconnect the EVAP canister vent shut valve 2P connector. Then turn the vehicle back to the ON mode and measure voltage between the EVAP canister vent shut valve 2P connector No. 1 and body ground. With the connector disconnected in ON mode, you should have battery voltage there. If battery voltage is present, the FI SUB RLY OUT wire is OK and you move on. If battery voltage is not present, repair an open in the FI SUB RLY OUT wire between PGM-FI main relay 1 and the EVAP canister vent shut valve.
Check the vent shut valve itself
Next, check the EVAP canister vent shut valve internal resistance. Turn the vehicle to the OFF (LOCK) mode and keep the vent shut valve 2P connector disconnected. On the vent shut valve side, measure resistance between connector No. 1 and connector No. 2. The specification is about 25－30 Ω at room temperature. If the valve measures about 25－30 Ω at room temperature, the valve is OK and you continue down the control circuit. If it does not, replace the EVAP canister vent shut valve.
Check the VSV control wire for a short to ground
Now move to the VSV line between the valve and the PCM. Turn the vehicle to the OFF (LOCK) mode. Jump the SCS line with the HDS and wait more than 1 minute, then disconnect PCM connector A, the 51P connector. With the EVAP canister vent shut valve 2P connector disconnected and PCM connector A disconnected, check continuity between PCM connector A No. 17 and body ground. If there is continuity, repair a short in the VSV wire between PCM A17 and the EVAP canister vent shut valve. If there is no continuity, the VSV wire is not shorted, so keep going.
Check the VSV control wire for an open
For the open check, keep the vehicle in OFF (LOCK) mode with the EVAP canister vent shut valve 2P connector disconnected and PCM connector A, the 51P connector, disconnected. Jumper EVAP canister vent shut valve 2P connector No. 2 to body ground. Then check continuity between PCM connector A No. 17 and body ground. If there is continuity, the VSV wire is OK. At that point, update the PCM if it does not have the latest software, or substitute a known-good PCM and recheck. If P0498 goes away after the PCM was updated, troubleshooting is complete. If P0498 goes away with the known-good PCM installed, replace the original PCM. If there is no continuity during the open check, repair an open in the VSV wire between PCM A17 and the EVAP canister vent shut valve.
Close
The clean way through P0498 is to prove the code first, verify the valve power feed, check the valve resistance, then test the PCM control wire for a short and for an open before blaming the controller. Keep each branch tied to the actual test result, and do not skip ahead on an intermittent. For more diagnostic training, visit stepdiagnostics.com.
Final check
P0498 is best handled as an electrical circuit diagnosis: confirm the fault, check power, check the valve, then prove the control wire before considering the PCM.
For more guided automotive diagnostics, visit STEP Diagnostics.
