FYI -- My books say to perform a sensor gear adaptation when you change out the motor mounts on a '98 & up M112/113 engines (V6 & V8 engines). Here is the info below:

"Some vehicles have an adaptation procedure to enhance the sensitization and reduce false misfire reporting.

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 convertor lock-up function
*Automatic transmission shift characteristics
*driveshaft and differential vibration

Misfire detection using the crankshaft position sensor requires sensor gear adaptation whenever the following componants are replaced:

*Flywheel or starting 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 monitered for misfire to protect the catalytic convertor. 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 prodice 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 as a functional test. A lower threshold enables the ECU to detect less severe misfires indicated by reading the RPM decrease and misfire fault counter for each cylinder.

The crankshaft sensor gear adaptation mean value reflects the addition of a supplementary correction factor designed to compensate for phase error in the crankshaft sensor. This information is used to compute actual ignition timing. Each segment represents the duration between each new ignition cycle. Ignition, injection and engine speed derived from segment duration are recalculated for each segment."

Hope this helps.

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