Specifications
72
Data Parameters Engine Parameters
PURGE VALVE DUTY CYCLE
Range: __________________________________________________________ variable
Used on HFM, ME10, ME20, ME27, and ME28 systems. The range varies by system:
• HFM; 5 to 15%
• ME10; 0 to 20%
• ME20; 0 to 20%
• ME27; 0 to 95%
• ME28; 0 to 95%
These parameters display the duty cycle of the purge valve, which is the amount of on time the
ECU is commanding. The display is only active when the purge valve is open (ON) and the value
varies with operating conditions, but should always be within the specified range.
PURGING
Range: __________________________________________________________ ON/OFF
Used on DM, ME10, and ME20 systems. This parameter displays the status of the evaporative
emissions (EVAP) purge valve. The display reads ON with the valve open and purge activated,
and OFF with the valve closed and purge deactivated. When the display reads ON, the PURGE
VALVE ON-OFF RATIO/DUTY CYCLE parameter should be displaying a value.
REAR AXLE SPEED
Range: ___________________________________________________ 0 to vehicle max
Used on ME27 and ME28 systems. This parameter indicates the speed of the rear axle based on
input signals to the ECU from the wheel speed sensors. The measurement units can be changed
from KPH to MPH.
RECIRCULATED AIR FLAP POSITION
Range: _________________________________________________________ 0 to 100%
Used on ME20 and SIM4 systems. This parameter indicates the opening of the air flap as a
percentage. The air flap controls supercharger boost and the signal is pulse-width modulated. At
0% the air flap is fully open and at 100% it is completely closed. At 11 to 99% boost control it is in
part load range; and at 10% or less the air flap is open.
REFERENCE RESISTOR VOLTAGE
Range: ________________________________________________________ 0 to 5.00 V
REFERENCE RESISTOR
Range: __________________________________________________________ variable
Used on EZ and HFM systems. These parameters indicate the value of the reference resistor
used for determining the internal fuel injection and ignition maps of the ECU. Up to seven
resistors with different calibrations can be activated by relocating plugs in a housing with an
integral resistance matrix. This permits adapting ignition-timing characteristics for different fuel
types. The RON (Research Octane Number) is the anti-knock quality of fuel. The higher the
number, the greater the resistance to knocking. Ignition timing can be retarded from 4 to 6
degrees, depending on whether RON 91 or 89 fuel is being used.