Circuit Description

VCM test Exhaust Gas Recirculation (EGR) valve by momentarily commanding valve on while monitoring engine MAP. VCM will illuminate MIL and store DTC P0401 if expected increase is not seen under certain conditions during deceleration.

Conditions for setting DTC:

• No ECT, EGR, EVAP, IAC, IAT, MAP, TP or VSS sensor DTCs set.
• No transmission DTCs set.
• Change in IAC less than 8 counts.
• ECT greater than 172°F (78°C).
• Vehicle speed greater than 27 MPH.
• BARO greater than 70 kPa.
• A/C clutch status unchanged.
• Transmission locked/unlocked status unchanged.
• No misfire DTC set.