Engine Start/Stop System - Function - GF30.00-D-0001H

ENGINES 642.992 in MODEL 906 with CODE (MJ6) Engine start and stop system 

The engine start and stop system (MSS) serves to achieve automatic cutting out and subsequently automatic starting of the engine to reduce fuel consumption or protect the environment if the vehicle is driven in city traffic or distribution traffic.

The MSS system is implemented in the CDI control unit (N3/20), with engine 642, or in CDI control unit (N3/21), with engine 646.

The MSS system is activated for a running engine by actuating the engine start/stop switch (S2/6) in the upper section and subsequent exceeding of the minimum speed of 2 km/h.

Activation is as follows depending on the equipment variant:

• For vehicles with code (JK3) High-end instrument cluster standard with speedometer in km via a message on the display (A1p1) of the instrument cluster (A1)
• For vehicles except code (JK3) High-end instrument cluster with speedometer with Km scale by brief lighting up of the ECO On indicator lamp (A1e4) in instrument cluster

The MSS system switches off the engine automatically if the following function requirements are fulfilled by associated components for at least 2 seconds:

• Engine runs at idle speed, from crankshaft sensor (L5), with engine 642, or from crankshaft sensor (L5/7), with engine 646, via direct line
• Vehicle stationary, from the ESP control unit (N30/4) via the Controller Area Network bus Class C (engine compartment) (CAN-C)
• Transmission in neutral or neutral position, from transmission neutral position switch (S164) via direct line
• Clutch pedal not pressed, from clutch pedal switch (S40/3) and from clutch pedal switch (S40/6) via direct line
• Coolant temperature > 40 °C, from coolant temperature sensor (B11) via direct line
• Outside temperature > 0 °C, from outside air temperature sensor (B14) via CAN-C
• Battery charge level (G1) is adequate, from alternator with LIN bus (G2/7) via local interconnect network (LIN)

If the engine was switched off automatically by the MSS system then also the corresponding settings of the "SPEEDTRONIC", with code (MS1) Cruise control, are switched off. After automatic starting of the engine by the MSS system the settings for the "SPEEDTRONIC" must be taken up again.

The MSS system starts the automatically switched off engine again if the following conditions apply for the associated components:

• Transmission in neutral or neutral position, from transmission neutral position switch via a discrete line
• Clutch pedal is operated (pressed), from clutch pedal switch (S40/3) via direct line or vehicle rolls, from ESP control unit via CAN C

If a gear position was selected after the MSS system automatically switched of the engine then during automatic starting of the engine by the MSS system the clutch pedal is pushed down all the way. Fully depressing the clutch pedal as far as the end stop is reported by the clutch pedal switch (S40/6) via a direct line to the CDI control unit.

The MSS system is deactivated by actuation of the engine start/stop switch in the lower section or through switching off the ignition (status "circuit 15 OFF").

In order to reactivate the MSS system again after switching off the MSS system by switching off the ignition (status "circuit 15 OFF"), the engine start/stop switch must first be actuated in the lower section and then subsequently actuated in the higher section.

The operation of the engine start/stop switch can only be read in by the CDI control unit via the following channel, if the engine hood switch (S62/41) reports the status "Engine hood closed":

• Via CAN C, with code (FZ5) Anti-theft alarm system (ATA), with code (FZ4) Anti-theft alarm system with interior protection and tow-away protection or with code (FY1) ATA 2 with interior protection, tow-away protection and battery-operated horn
• Via direct line, except code (FZ5) Anti-theft alarm system (ATA), except code (FZ4) Anti-theft alarm system with interior protection and tow-away protection and except code (FY1) ATA 2 with interior protection, tow-away protection and battery-operated horn

Engine start/stop system - system display	With code (JK3) instrument cluster, high end with speedometer with Km scale	GF30.00-D-0001-01HH
	Except code (JK3) instrument cluster, high end with speedometer with Km scale	GF30.00-D-0001-01HL
Component description for the engine start/stop system switch		GF30.00-D-4000H