Mercedes-Benz Vehicle Communication Software Manual [702kb ...

Data ParametersEngine Parametersensure communication if one wire is damaged and provide the ability to recognize a CAN circuitfault. The two lines must not be interchanged as each represents either high or low level.BRAKE SWITCHRange: __________________________________________________________ ON/OFFUsed on ME10 systems. This parameter is an ECU input that indicates brake pedal position. Thedisplay should read ON with the brake pedal depressed and OFF at all other times.CAMSHAFT HALL-EFFECT SENSORRange: __________________________________________________________ variableUsed on ME10, ME20, ME27 and ME28 systems. This parameter indicates the state of thesignal from camshaft position (CMP) sensor. On ME10 and ME 20, the reading switchesbetween “55” and “AA,” depending on whether the Hall-effect signal is high or low. The valueshould by constantly switching whenever the engine is running, and the frequency of theswitching increases and decreases in proportion to engine speed. Be aware, readings may beoutside the normal range when the engine is cranking.On ME27 and ME 28 systems, the parameter should read “Running” when the engine is runningand “Not Running” when the engine is not running.CAMSHAFT ADJUSTMENTCAMSHAFT CONTROLCAMSHAFT SOLENOIDCAMSHAFT TIMINGRange: __________________________________________________________ ON/OFFUsed on DM, DM2, LH, HFM and SIM4 systems. These parameters display the ECU signals tothe variable camshaft timing solenoid. When ON, the ECU is energizing the solenoid to advancecamshaft timing. Typically on 119 and 120 engines, the display reads OFF at idle and switches toON at 2000 RPM. For all other engines, the display waits until 4000 RPM before switching to ON.CAMSHAFT ADJUSTMENT VALVE, RIGHTCAMSHAFT ADJUSTMENT VALVE, LEFTRange: __________________________________________________________ ON/OFFUsed on ME27 and ME28 systems. This parameter indicates whether the variable camshafttiming solenoid is on or off. Below 1500 RPM, the camshaft timing solenoid is OFF or deenergized—camtiming is retarded to reduce valve overlap which reduces residual exhaust gas.Between 1500 and 4000 RPM the camshaft timing solenoid is ON or energized. Cam timing isadvanced to reduce mixture loss and improve performance. Above 4000 RPM, the camshafttiming solenoid is OFF or de-energized. Cam timing is retarded to improve cylinder re-charge.CAMSHAFT CONTROL LOGIC CHAINRange: __________________________________________________________ YES/NOUsed on DM2 systems. This parameter indicates whether the onboard self diagnostic tests haverun for the variable camshaft control system.CAMSHAFT REFERENCE MARK SIGNALRange: __________________________________________________________ YES/NOUsed on DM2 systems. This parameter indicates whether the camshaft reference mark signal ison (YES) or off (NO). The Scanner normally displays NO with the key on, engine off, and when acamshaft position sensor fault exists.42