P2420-85: Evaporative Emission Control System Switching Valve Control Circuit High - Signal above allowable range: Action

NOTE:

If purge valve related DTCs are also set, perform the relevant corrective action(s) first.
It is not possible to replicate the failure event as certain entry conditions must be satisfied (for more information, refer to Evaporative Emissions - DESCRIPTION AND OPERATION ). To verify the customer concern, perform routine Evaporative System Diagnostic Check and re-read DTCs.

Refer to the applicable SYSTEM WIRING DIAGRAM(S) and check the diagnostic module tank leakage changeover valve circuit for short circuit to power