Vehicle Speed Calculation

Vehicle speed is calculated by the IPC based on the dedicated vehicle speed input. The dedicated vehicle speed input is sent from the PCM in the form of a pulse train consisting of 4000 pulses per mile. Vehicle speed may be offset from the actual vehicle speed if certain export option bits are set. The DIC display will not be turned on when the vehicle options are programmed in the assembly plant. This message may be turned on by setting a bit in the option byte E.

NOTE: Only turn this message on if a customer insists on having a digital speed readout. For analog IPC's the digital speed readout, and the analog (needle) display may not Always read the exact same speed. This must be explained to the customer prior to turning on the message. The analog gage still meets all government requirements even though the Digital and analog readouts may be slightly different.

Average Speed
Average Speed (MPH) is calculated by the IPC as described below.

The "AVERAGE SPEED" feature is an indication of the vehicle's average road speed since the last reset of the parameter.

Average Speed - Total Distance Traveled/Total Time (the ignition switch is in "RUN")

The display is centered on the Driver Information Center with these graphics:
English XXX.X AVG MPH
Metric XXX.X AVG km/h

If AVERAGE SPEED is the Driver Information Center Display Mode at power OFF, it will be the display mode at power ON after initialization, if no Driver Warning messages are current.
To reset the AVERAGE SPEED value, the AVERAGE SPEED must be displayed on the Driver Information center by using the INFORMATION key. Once AVERAGE SPEED is displayed, pushing the RESET key for greater than one second will Clear the distance and time registers and cause the following to be displayed for the duration of the key press and for 500 milliseconds after the key is released:
English 0.0 AVG MPH
Metric 0.0 AVG km/h

The AVERAGE SPEED display mode can be exited by pushing the INFORMATION key. Elapsed time will be the subsequent display mode. This message may be suppressed using Option Byte E.