Trip Indicator

The trip is essential for running monitors and turning off the Malfunction Indicator Light (MIL). A trip is defined as a set of vehicle operating conditions that must be met for a specific monitor to run. All trips begin with an ignition key cycle. Good trip counters are: global good trip, fuel system good trip, misfire good trip and alternate good trip (appears as Global Good Trip on DRBIII(R)).

• Global Good Trip
  
  To increment a Global Good Trip, the oxygen sensor and catalyst efficiency monitors must have run and passed, and engine run time must be more than 2 minutes.
• Fuel System Good Trip
  
  To count a good trip (3 required) and turn off the MIL, the following conditions must be met. Engine must be in closed loop, must be operating in similar conditions window and short term multiplied by long term must be less than threshold value. For more information on similar conditions window, see SIMILAR CONDITIONS WINDOW  .
• Misfire Good Trip
  
  If operating in similar conditions window and 1000 engine revolutions have occurred with no misfires, the PCM will count one good trip (3 required) in order to turn off MIL.
• Alternate Good Trip
  
  Alternate Good Trips are used in place of Global Good Trips for Comprehensive Components and Major Monitors. If the Task Manager cannot run a Global Good Trip because a component fault is stopping the monitor from running, it will attempt to count an Alternate Good Trip. The Task Manager counts an Alternate Good Trip for Comprehensive components when the following conditions are met: Two minutes of engine run time, idle or driving and no other faults occur. The Task Manager counts an Alternate Good Trip for a Major Monitor when the monitor runs and passes. Only the Major Monitor that failed needs to pass to count an Alternate Good Trip.
• Warm-Up Cycles
  
  Once the MIL has been turned off by the Good Trip Counter, the PCM will automatically switch to a Warm-Up Cycle Counter that can be viewed by the DRBIII(R) scan tool. Warm-up cycles are used to clear DTCs and freeze frame data from PCM memory. Forty warm-up cycles are necessary to clear DTCS and freeze frame data. A warm-up cycle is defined as the engine is started, an increase of 40°F (4°C) in engine coolant temperature exists after engine is started and engine coolant temperature reaches at least 160°F (71°C).