Monitor Description

There is a HCAC VSV monitoring circuit in the ECM. The monitoring circuit voltage becomes lower When the HCAC VSV is turned on, and it becomes higher when the HCAC VSV turns off.

If the monitoring circuit voltage is low when the HCAC VSV turns off, the ECM interprets this as a malfunction. The ECM illuminates the malfunction indicator lamp (MIL) and sets the diagnosis trouble code (DTC).