Circuit Description

While engine is warming, VCM monitors ECT sensor to determine the amount of time it takes engine to reach coolant temperature required for closed loop operation. Test will not be run if either intake air or engine coolant temperature are less than predetermined temperature. VCM will only run test on a cold start and only once per cold start.

DTC will set when the following conditions are present:

• Engine running.
• No ECT or IAT related DTCs.
• DTC P0117 or P0118 not active.
• ECT and IAT is greater than -40°F (-40°C).
• Start-up ECT is -40°F (-40°C) or less.
• Closed-loop timer greater than 4 minutes.
• Minimum stabilized ECT is less than 68°F (20°C).