Specifications
56
Data Parameters Engine Parameters
HOT WIRE AIR MASS
HOT FILM MASS AIR FLOW SENSOR
Range: ______________________________________________________ 0 to 500 kg/h
These parameters are an ECU calculation of the mass of the intake air charge in kilograms per
hour (kg/h) based on the input of the hot film mass airflow sensor. Normal hot idle values vary
depending on engine. In general, readings from 15 to 30 kg/h are normal for a hot engine running
at idle with all accessories switched off.
HFM-SFI MAP
Range: ______________________________________________________ not available
Used on HFM systems. No information is available at this time.
HOLD GEAR
Range: __________________________________________________________ ON/OFF
Used on ME10 and ME20 systems. This parameter is a cruise control input that indicates if the
ECU is maintaining a transmission range during hill climbing or other high-load condition. Reads
ON when a specific gear is being held, and OFF during normal driving conditions.
IDLE FUEL TRIM ADAPTATION LEFT
IDLE FUEL TRIM ADAPTAT. RIGHT
Range: _________________________________________________________ –1 to 1ms
IDLE FUEL TRIM CYL. 1-3 RIGHT
IDLE FUEL TRIM CYL. 4-6 RIGHT
IDLE FUEL TRIM CYL. 7-9 LEFT
IDLE FUEL TRIM CYL. 10-12 LEFT
Range: ______________________________________________________ –0.7 to 0.7ms
Used on ME27 and ME28 systems. These fuel trim numbers represent the fine tuning long term
correction to the fuel injection pulse width to either individual banks or groups of cylinders. This
number is learned by the ECU and used to correct small differences between engines and
engine wear. When the short term correction is outside the window defined in the ECU memory,
the long term fuel trim is changed. Each change in the Long Term Fuel Trim is equivalent to a
change of the Short Term Fuel Trim over its entire range. When the short-term Fuel Trim reaches
its upper or lower limit, it resets back to the beginning, and moves the long term fuel trim up or
down by one count. The short term fuel trim continues to move very quickly and if the limits are
reached, it again will increment the long term fuel trim. This will continue until either the fuel
mixture problem is corrected or long term fuel trim reaches its limit and a DTC sets.
This type of adaptation adjusts long term fuel trim in small, incremental amounts. It is also called
Additive Mixture Adaptation because it can modify the duration of injection by adding or
subtracting to the entire fuel map by a incrementally small amount, which affects all cells equally
the same. It thus affects the entire engine speed range or all fuel map cells, but is most
noticeable at idle because of the minimal amount of adjustment capability.
Additive Mixture adaptation addresses faults that are most severe at idle, and lessen in severity
as engine speed increases. A vacuum leak would be a typical example. This type of adaptation
is not dependent on base injection duration.
IDLE SPEED CONTROL
IDLE SPEED DETECTION
IDLE SPEED RECOGNITION
Range: __________________________________________________________ YES/NO
Used on DM, ERE/EVE/ASF (IFI Diesel)), ME27, ME28, and SIM4 systems. These parameters
indicate whether the idle speed control circuit is on or off.