We had a customer with a 2014 Toyota Rav4 come in with a P0446 trouble code. The code description reads, “Evaporative Emission [EVAP] System Vent Control Circuit Malfunction”. So we proceeded to check the EVAP system.
Evaporative Control System Diagnostics
We checked the purge valve by energizing it and seeing if it actuates and it seemed fine. Then we checked the EVAP system for leaks. We then found that there was a leak on top of the gas tank.
In this case had to bring down the gas tank to see exactly where it was leaking from. Once we lowered the gas tank we lightly pressurized with 2 PSI of air and sprayed it down with soapy water.
We then observed that the bubbles were forming where the fuel pump bolts to the gas tank. We figured that the seal had failed. We proceeded to remove the fuel pump and to our big surprise the fuel pump canister’s plastic flange had actually cracked allowing the fuel vapors to escape causing the check engine light for the EVAP system. It was surprising as the Toyota Rav 4 only had 60,000 miles which is fairly low mileage compared to other cars we reapir at our shop.
The Fix
Then we proceeded to replace the fuel pump assembly with a new unit after cleaning the inside of the gas tank to ensure the new fuel pump has a nice long service life. We replaced the seals and locking ring too as the original was rusty. We then re-installed the gas tank and cleared the check engine light. Then we confirmed that there were no leaks and the check engine light was off for good!
New Fuel Pump Assembly Solved the Check Engine Light
If you have a vehicle with a check engine light you’d like us to diagnose or maintain, feel free to Contact Us @ Tolima’s Auto Center.
