Emissions - DTC P2422/Evap System Blockage

Got DTC P2422? Check for an EVAP System Vent Blockage

NOTE:
This article applies to '03-06 MDXs, '05-06 RSXs, 04-06 TLs, and '04-06 TSXs.

Got a vehicle in your shop with DTC P2422 (EVAP canister vent shut valve closed malfunction)? An EVAP system vent blockage is the likely culprit. It can slow down the venting process, setting this DTC.

Interestingly, the most common culprit reported is a spider's nest (a yellow sac spider's to be exact) in the fitting that connects the hose to the vehicle frame. Another common culprit is a blocked EVAP canister Use the HDS to run the EVAP system function test to find out if the system really has a problem. If it looks like a blockage is possible, then follow this procedure to track it down:

1. From the Mode Menu on the HDS, select Inspection.

2. From the Inspection Menu, select EVAP TEST. From the EVAP TEST MENU, select MULTI SOLENOIDS. From the Multi Solenoids Menu, select PCS (CPV) ON, CVS ON.

3. Record the FTP Sensor value on the display screen. [This is for key on, cap off(KOCO).] Reinstall the fuel fill cap.

4. Disconnect the purge line between the PCS and the intake manifold.

5. Connect a hand vacuum pump to the line toward the PCS.

NOTE:
On RSXs, the PCS is mounted to the throttle body. To apply vacuum to the EVAP system, you've got to unbolt the PCS and attach the vacuum pump hose to the nipple leading to the throttle body.

6. Pump the handle until the FTP Sensor value reads 1.60 volts. Keep in mind, you're evacuating the EVAP canister, so you might need to do a lot of pumping to reach this value.

7. Unplug the PCS connector, and disconnect the vacuum pump. The FTP Sensor value should stay the same.

8. Plug in the PCS connector, and record how long it takes for the sensor value to return to the value you recorded in step 3.

9. Connect the vacuum pump to the line toward the PCS, and pump the handle until the FTP Sensor value reads 1.60 volts.

10. Unplug the CVS connector, and record how long it takes for the sensor value to return to the recorded value.

11. Compare your recorded PCS and CVS venting times. The PCS venting time should be 1 to 2 seconds longer than the CVS venting time.

^ If the venting times meet the criteria, press on with normal troubleshooting.

^ If the venting times differ widely, look for a vent blockage on the side of the EVAP system with the longer venting time. Fix the blockage problem, then run the EVAP system function test again to make sure the problem is fixed.