amgboy916

i have a 2012 cls 63 with 55k miles
i was driving and i had that dreaded eco mode on and my car shut off at a stop and then wouldnt start again!

now my car wont start at all it wont even crank ive tried to jump start it multiple times it has power and the key unlocks and locks the car fine and i can put key into the igniton and twist it fully but it will not crank at all i tried my spare key as well and same thing
i tried changing the battery on the keys as well.

please help im frustrated theres no error codes or anything this car shouldnt be doing this i just got it 3 months ago

im really trying to avoid towing it to the dealership but i may have to

Plutoe

Post your VIN!

Mmr1

What is the battery voltage, do headlights light up bright? The battery is 5 years old.

TommiM

I have seen the starter itself go bad. Especially since the introduction of the eco start/stop, the starter gets worked much more so expect to see lower life spans of starters. When I first started in this field I never really saw many bad starters as I have recently. Without actually looking at short test, I would say either wiring, relay, or starter is your culprit.

Mmr1

Does the starter restart it with Echo mode? I read the computer knows which cilinder is in firing position and fires just that cilinder to start the motor. No battery or starter wear!

TommiM

It still uses the starter though. In order to reduce starting time and be more efficient, the ecu monitors where the engine is at in regards to firing order, tdc, etc. You have things like the voltage dip lmiiter to reduce dimming lights while the engine restarts, but it still uses the starter.


GF54.10-P-1040FQ
ECO start/stop function energy management, function
27.5.14MODEL 218
with CODE B03 (ECO start/stop function)
The function "Engine start/stop energy management, function" is viewed from an energy management point-of-view. Detailed information on the "Engine timing start/stop function" is documented in the "Common rail diesel injection (CDI), function" (with diesel engine) or "Gasoline injection and ignition system with direct injection, function" (with gasoline engine) function description.



- - - - - - - - - -Function requirements, general

• Engine running and at operating temperature
• Engine hood closed
• One-time overspeeding of v = 15 km/h in forward travel
• System diagnosis completed
• Outside temperature T = -10 to 40 °C
• Battery temperature T = 0 to 60 °C
• A/C regulated

Energy management for engine start/stop, general
Switching of the engine during standstill periods of the vehicle reduces the fuel consumption and therefore the carbon dioxide emissions. The master control unit for the engine start/stop function is the CDI control unit (N3/9) (with diesel engine) or the ME-SFI [ME] control unit (N3/10) (with gasoline engine), that records and evaluates all influencing factors. For a stationary vehicle, the engine Start-Stop function switches the engine off automatically and starts it again, as soon as the driver wishes to drive off.
It is still possible to stop and start the engine in the conventional way.

Up to 31.08.2014 and as of 01.09.2014, vehicles with engine 642 or CODE 494 (USA version):
By using the ECO start/stop function additional battery (G1/13) with a capacity of 12 Ah, the voltage dip perceived by the vehicle occupants when the engine is started (e.g. during radio or ventilation operation) is prevented. The additional battery for ECO start/stop function then assumes the power supply for the active consumers in the process while the on-board electrical system battery (G1) is isolated from the on-board electrical system (at engine start). Active comfort functions are not switched off. The additional battery for the ECO start/stop function is activated by actuation of the ECO start/stop function additional battery relay (K114). The on-board electrical system battery is decoupled from the on-board electrical system by actuation of the on-board electrical system decoupling relay (K19/7). In addition, the front SAM control unit with fuse and relay module (N10/1) checks that all components involved in isolating the on-board electrical system battery and connecting the ECO start/stop function additional battery are functioning correctly.

As of 01.09.2014, vehicles without engine 642 and without CODE 494 (USA version):
By using a series resistor at the positive terminal of the on-board electrical system battery, the voltage dip perceived by the vehicle occupants when the engine is started (e.g. during radio or ventilation operation) is reduced. The voltage dip limiter (R62) (series resistor) reacts to the dip in voltage which occurs when the engine is started. The front SAM control unit evaluates the status of the voltage dip limiter via a direct line.
The voltage dip limiter (series resistor) is an electrically switchable series resistor used to reduce the high power consumption of the starter (M1) when the engine is cranked. If this high power consumption of the starter has been reduced by the series resistor, the voltage dip limiter switches the series resistor out again during the starting procedure.

The engine start/stop function encompasses the following subfunctions:

• Function sequence for engine stop
• Function sequence for engine start
• Function sequence for forced engine start
• Function sequence for determining state of ECO start/stop function additional battery (up to 31.08.2014 and as of 01.09.2014, vehicles with engine 642 or CODE 494 (USA version))
• Function sequence for charging ECO start/stop function additional battery (up to 31.08.2014 and as of 01.09.2014, vehicles with engine 642 or CODE 494 (USA version))

- - - - - - - - - -Additional function requirement for engine stop

• Stop enable issued by the CDI control unit or the ME-SFI [ME] control unit

Function sequence for engine stop
As the master control unit for the engine start/stop function, the CDI control unit or the ME-SFI [ME] control unit checks the various influencing factors for the stop enable: The energy management system provides information for this which describes the on-board electrical system status or the requirements for the on-board electrical system.
While the engine is running, the CDI control unit or ME-SFI control unit assesses the operating rate of the alternator (G2). The alternator and the CDI control unit or the ME-SFI control unit communicate with each other via the drive train LIN (LIN C1). The CDI control unit or ME-SFI control unit then sends the "engine running" signal and information on the operating rate of the alternator via the chassis CAN (CAN E) (up to 28.02.2013) or chassis CAN 1 (CAN E1) (as of 01.03.2013), the front SAM control unit and interior CAN (CAN B) to the rear SAM control unit with fuse and relay module (N10/2).
The rear SAM control unit receives them, reads in the data from the battery sensor (B95) via the on-board electrical system LIN (LIN B7), evaluates the state of the on-board electrical system battery and sends information that describes the state of the on-board electrical system or the requirements with regard to the on-board electrical system, via the interior CAN, front SAM control unit and chassis CAN (up to 28.02.2013) or chassis CAN 1 (as of 01.03.2013) to the CDI control unit or ME-SFI control unit.

The sent information includes the following:

• State of on-board electrical system battery
• State of ECO start/stop function additional battery (up to 31.08.2014, as of 01.09.2014, vehicles with engine 642 or CODE 494 (USA version))
• On-board electrical system status

The CDI control unit or ME-SFI control unit evaluates all relevant variables, issues the stop enable accordingly and stops the engine. The CDI control unit or ME-SFI control unit then sends the "drivetrain operational" signal via the chassis CAN (up to 28.02.2013) or chassis CAN 1 (as of 01.03.2013), the front SAM control unit and the interior CAN to the rear SAM control unit. This prevents the energy management from starting the process of consumer reduction or consumer shutoff as the signal "Engine running" is not transmitted.
While the vehicle is at a standstill the brake pedal must remain pressed or the "Hold" function be active.
The blower output is reduced when the automatic blower speed function of the air conditioning is active. In high ambient temperatures the system changes into air circulation mode depending on the specified temperature adjusted.

After the engine has been switched off a maximum of three engine starts within a period of t = 1 minute (maximum idle time t = 180 s) with exceeding the speed threshold of v = 8 km/h are permitted.
- - - - - - - - - -Function sequence for engine start
The engine is started with the actuation of the accelerator pedal.
Up to 31.08.2014 and as of 01.09.2014, vehicles with engine 642 or CODE 494 (USA version):
During the starting procedure the on-board electrical system battery is isolated from the on-board electrical system. The power supply for the active consumers is now provided by the additional battery for the ECO start/stop function. This serves to prevent any voltage dip as perceived by vehicle occupants when starting the engine (e.g. during radio or ventilation operation).
The CDI control unit or the ME-SFI [ME] control unit evaluates all relevant influencing factors and then issues the start enable (hot start signal). The front SAM control unit reads in this hot start signal via a direct line and directly actuates the on-board electrical system decoupling relay in the front prefuse box (F32) and the ECO start/stop function additional battery relay at the ECO start/stop function additional battery.
The additional battery for the ECO start/stop function is then switched through to the on-board electrical system. The on-board electrical system decoupling relay isolates the on-board electrical system battery from the on-board electrical system for the duration of the starting procedure. The energy requirement of the on-board electrical system is now solely provided by the ECO start/stop function additional battery. The on-board electrical system battery now supplies the energy required for the engine starting process.
As soon as the CDI control unit or the ME-SFI control unit detects an engine speed of n = 400 to 700 rpm, it stops the starting procedure and sends the "engine running" signal via the chassis CAN (up to 28.02.2013) or chassis CAN 1 (as of 01.03.2013) to the front SAM control unit and additionally via the chassis CAN (up to 28.02.2013) or chassis CAN 1 (as of 01.03.2013), front SAM control unit and interior CAN to the rear SAM control unit. The front SAM control unit then directly actuates the on-board electrical system decoupling relay and the ECO start/stop function additional battery relay. The on-board electrical system decoupling relay reconnects the on-board electrical system battery to the on-board electrical system. The additional battery relay for ECO start/stop function disconnects the additional battery for ECO start/stop function from the on-board electrical system. The energy requirement of the on-board electrical system is now supplied again by the on-board electrical system battery.

As of 01.09.2014, vehicles without engine 642 and without CODE 494 (USA version):
By using a voltage dip limiter (series resistor) at the positive terminal of the on-board electrical system battery, the voltage dip perceived by the vehicle occupants when the engine is started (e.g. during radio or ventilation operation) is reduced.
The CDI control unit or the ME-SFI control unit evaluates all relevant variables and starts the engine. As soon as the CDI control unit or the ME-SFI control unit detects an engine speed of n = 400 to 700 rpm, it terminates the starting procedure and sends the "engine running" signal via the chassis CAN (up to 28.02.2013) or chassis CAN 1 (as of 01.03.2013), the front SAM control unit and the interior CAN to the rear SAM control unit.
- - - - - - - - - -Function sequence for forced engine start
To ensure that the on-board electrical system stability is also given during engine OFF, the CDI control unit or the ME-SFI [ME] control unit can also force the engine to start. A forced engine start is also conducted if, as a consequence of load-intensive consumers, the on-board electrical system stability can no longer be assured.
Load-intensive consumers can be requested by the following systems:

• PRE-SAFEŽ
• Brake assist and adaptive cruise control systems
• Air conditioning

As soon as the energy management is no longer able to ensure stability of the on-board electrical system, the rear SAM control unit sends the "start engine" request via the interior CAN, front SAM control unit and chassis CAN (up to 28.02.2013) or chassis CAN 1 (as of 01.03.2013) to the CDI control unit or to the ME-SFI control unit. The CDI control unit or the ME-SFI control unit then starts the engine.
If, following this, the on-board electrical system stability can still not be assured, the engine is no longer switched off. The engine start/stop function is deactivated.
The rear SAM control unit calculates the required alternator specified voltage on the basis of the data from the battery sensor and sends it via the interior CAN, front SAM control unit and chassis CAN (up to 28.02.2013) or chassis CAN 1 (as of 01.03.2013) to the CDI control unit or to the ME-SFI control unit. This makes the CDI control unit or the ME-SFI control unit start the alternator regulation (alternator management). For this purpose, the CDI control unit or the ME-SFI control unit assesses the operating rate of the alternator and requests the corresponding specified voltage (excitation voltage). The alternator and the CDI control unit or the ME-SFI control unit communicate with each other via the drivetrain LIN. The CDI control unit or the ME-SFI control unit then sends information on the operating rate of the alternator via the chassis CAN (up to 28.02.2013) or chassis CAN 1 (as of 01.03.2013), front SAM control unit and interior CAN to the rear SAM control unit.

Detailed information about alternator regulation can be found in the separate function "Engine ON energy management, function".

Illustration showing principle of power supply at engine start (up to 31.08.2014 and as of 01.09.2014, vehicles with engine 642 or CODE 494 (USA version)) B95Battery sensorG1On-board electrical system batteryG1/13ECO start/stop function additional batteryG2AlternatorK19/7On-board electrical system decoupling relay (relay open)K114Additional battery relay for ECO start/stop function (relay closed)M1StarterN10/1Front SAM control unit with fuse and relay moduleN10/2Rear SAM control unit with fuse and relay module
P54.10-3625-05
Illustration showing principle of power supply during engine operation (up to 31.08.2014 and as of 01.09.2014, vehicles with engine 642 or CODE 494 (USA version)) B95Battery sensorG1On-board electrical system batteryG1/13ECO start/stop function additional batteryG2AlternatorK19/7On-board electrical system decoupling relay (relay closed)K114Additional battery relay for ECO start/stop function (relay open)M1StarterN10/1Front SAM control unit with fuse and relay moduleN10/2Rear SAM control unit with fuse and relay module
P54.10-3626-05
Function sequence for determining state of ECO start/stop function additional battery (up to 31.08.2014 and as of 01.09.2014, vehicles with engine 642 or CODE 494 (USA version))
The front SAM control unit performs battery state recognition immediately after the engine is started, and sends the result via the interior CAN to the rear SAM control unit. This provides information regarding the availability of electrical power to the additional battery for the ECO start/stop function. If the engine is switched off during the battery state recognition, the SAM control unit switches this off and discards the previous results.
In addition to battery state recognition, the voltage at the ECO start/stop function additional battery is checked after every engine start.

Battery state recognition can be started using the diagnostic tester.

The additional battery relay for the ECO start/stop function is no longer actuated under the following conditions:

• Additional battery for ECO start/stop function deep discharged
• Short circuit in additional battery for ECO start/stop function
• Short circuit in positive line of additional battery for ECO start/stop function

In order to establish this, the voltage of the ECO start/stop function additional battery is compared with a value stored in the front SAM control unit.
A corresponding fault message is shown in the multifunction display (A1p13) of the IC (A1). The front SAM control unit transmits the data required for this to the instrument cluster via the interior CAN.
- - - - - - - - - -Function sequence for charging ECO start/stop function additional battery (up to 31.08.2014 and as of 01.09.2014, vehicles with engine 642 or CODE 494 (USA version))
The ECO start/stop function additional battery is charged by means of actuation of the ECO start/stop function additional battery relay.
The charging strategy of the additional battery for ECO start/stop function must take two requirements into account:

• The ECO start/stop function additional battery must always be sufficiently charged.
• The number of additional battery relay for the ECO start/stop function actuations and the related load on the additional battery for the ECO start/stop function must be minimized as far as possible.

If the open circuit voltage (U > 12.5 V) of the additional battery for ECO start/stop function is too low, the alternator's power limit (alternator management) is deactivated so that the additional battery for ECO start/stop function can be charged. For this purpose, the rear SAM control unit sends the "Actuate ECO start/stop function additional battery relay" request via the interior CAN to the front SAM control unit.

If the voltage dip (U < 11 V) at engine start is too large, an engine stop is deactivated for t = 5 minutes to recharge the additional battery for the ECO start/stop function.
The additional battery for ECO start/stop function is only connected when the alternator's power limit (alternator management) is not active and the on-board electrical system voltage (U > 13 V) is high enough. It is cleared again when the alternator's power limit is active or the on-board electrical system is severely overloaded.

Electrical function schematic for energy management for engine start/stop
PE54.10-P-2070-97XAA




Overview of energy management system components
GF54.10-P-9990FQ

amgboy916

Sorry i forgot to update it turned out to be the starter had to get the whole thing replaced now im focusing on making this car more reliable should i get thr weistec coolant upgrade to separate the cooling systems? May be a little off topic