Specifications

Data Parameters Engine Parameters

the base point, or no correction. Readings above 1.0 indicate a rich correction, or increased fuel,

and readings below 1.0 indicate a lean correction, or reduced fuel. All corrections are made in

three ranges: closed throttle position, lower partial load and upper partial load. The ECU

multiplies the actual mass of the air inducted into the engine by the correction factor (% positive

or negative) to determine the injection time. For example, if the actual air mass is 150 kg/h and

the Scanner reading is 1.10 (positive 10%), a computed air mass value of 165 kg/h (150 x

1.1(10%) = 165) is used for injection time.

The MIL will come on when self-adaptation reaches the range limit.

SENSITIZATION FACTOR

SENSOR GEAR FILTER 1

SENSOR GEAR FILTER 2

Range: ______________________________________________________ not available

SNSR GEAR ADAPT. MEAN VALUES SEG. A TO E

Range: __________________________________________________________ variable

SENSOR ROTOR ADAPTATION

SENSOR ROTOR ADAPTATION COMPLETED

Range: __________________________________________________________ YES/NO

These parameters are all related to crankshaft sensor misfire detection sensitization. An

adaptation procedure to enhance the sensitization and reduce false misfire reporting is used on

some models.

Sensor Gear (Flywheel) adaptation may be required on ME-SFI 1.0, 2.0, 2.1, and 2.8. Sensor

Gear adaptation started approximately in 1998 with the ML 112/113 engines. Later ME 2.8 and

SIM4 may also use this function. The adaptation re-configures the ME controller for increased

sensitivity for misfire detection.

Drive train influences on misfire detection are:

• crankshaft flex

• motor mount movement

• torque converter lock-up operation

• automatic transmission shift characteristics

• drive shaft and differential vibration

Misfire detection using the crankshaft position sensor requires sensor gear adaptation whenever

the following components are replaced:

• flywheel or starter ring gear

• crank sensor (L/5)

• ECU

• motor mounts

In some cases, sensor gear adaptation must be performed after a misfire code.

The engine is constantly monitored for misfire to protect the catalytic converter. The engine is

analyzed by evaluating the crankshaft position sensor using a sophisticated mathematical

method to determine whether precise time synchronism exists between individual combustions.

Each individual combustion must produce a characteristic acceleration at the flywheel. If misfire

occurs, flywheel rotation slows slightly. These parameters are the amount of correction the ECU

is making to filter out vibration and prevent setting false misfire codes. The ECU sets irregular

engine running analysis or misfire detection to a less sensitive setting when driving on a poor

road surface. The body acceleration sensor, or electronic vibration module, detects a rough road

and sends this information to the ECU. The misfire sensitivity level can also be altered with the