Massachusetts Vehicle Check - Mass08 Management Module ...

Non Commercial
Enabling Criteria
The exact operating conditions are needed before a test can run. These are provided
by a trip.
DTC
A Diagnostic Trouble Code (DTC) is commonly referred to as a fault code. A
DTC is stored in memory when a fault is detected that can result in excessive emissions.
MIL Operation
The OBD II Malfunction Indication Lamp (MIL) illuminates
when a DTC is stored. The MIL will stay on unless:
1. DTCs are erased by a command from the scan tool.
2. Power is removed from the PCM or the PCM is disconnected.
3. The PCM turns the MIL off. The PCM will shut off the MIL if the monitor that set
the DTC runs and passes on three consecutive trips.
DTC (Code) Set Parameters
DTC (code) Set Parameters
are a set of conditions required
before a DTC will be set. These
conditions are a combination of
enabling criteria and test standards.
IAT = Intake Air Temperature
The Engine Coolant Temperature
(ECT) image to the above right, displays conditions that must be met before an ECT DTC will
be set on a specific make and model vehicle.
Massachusetts Vehicle Check
Ch. 3 - 5