Some 2008-2010 model year Japan-built Toyota vehicles may exhibit a MIL on with DTC P2420 (evaporative emission system switching valve control circuit high). The charcoal canister has since been updated to address this condition. Models include 2009-2010 Highlander and Highlander HV, and 2010 4Runner, Camry, FJ Cruiser, Land Cruiser, Prius, RAV4 and Yaris.
1. Using TIS Techstream, check for DTCs. If DTCs other than P2420 are stored, address these before proceeding.
2. Inspect VSV for proper power and ground circuits.
a. Check voltage between Pin 9 (VLVB) and chassis ground. With ignition on, voltage should read between 9 and 14 V. If OK, proceed to the next step.
b. Check for voltage between Pin 8 (VGND) and chassis ground. With ignition on, voltage should read between 9 and 14 V. If yes, proceed to step 2C. If no, the vent valve is open, then proceed to Step 3.
c. Using TIS Techstream, activate the VSV and check voltage between Pin 8 (VGND) and chassis ground.
3, If less than 1 volt is seen, or if the vent valve is open, replace the charcoal canister assembly.