ECO mode

[markjay]

My 2013 W204 is still on its original battery. The car is currently garaged. I do not use a trickle charger.

Yesterday I drove it to the office, just to keep the car rolling from time to time. It's a 14 miles round trip, in slow traffic, about 45 minutes each way.

When starting the car, the ECO symbol did not come-up at all, and the ECO button wouldn't turn it on either. This is normal (for my car) after it has not been driven for a few weeks. The battery was fine however for starting the engine as per usual.

On the way to the office, the ECO symbol finally came-up, but yellow (not ready). Halfway through the way back from the office, the ECO symbol became green (ready). So it took ~10 miles of driving and ~1h of charging for the battery to fully recover. This is with an 8-years old MB-branded battery.

So my battery isn't performing as well as when it was younger (neither do I...), but then it's still good and does not need replacing just yet (and so am I, hopefully) .

Just to provide some sense of proportion.

 

[TeddyRuxpin]

I have a pretty cheap "GPSLive" car tracker while tells me the battery voltage in real time, on my phone, which is pretty useful. I also have the Ctek but I haven't needed to use it since lockdown. In fact I think my brother stole it for one of his old MG batteries *shakes fist*

 

[ToeKnee]

I have a pretty cheap "GPSLive" car tracker while tells me the battery voltage in real time, on my phone, which is pretty useful. I also have the Ctek but I haven't needed to use it since lockdown. In fact I think my brother stole it for one of his old MG batteries *shakes fist*

I use that function too, very useful!

 

[Bobby Dazzler]

This might be helpful in understanding why stop-start systems appear to have a
Ind of their own! They don’t, there are just multiple factors or conditions.

Source: Preconditions for the ECO start/stop function

It is not always expedient for the engine to be shut down automatically when the vehicle comes to a standstill. The auto-stop function will therefore only be initiated if a number of conditions are met:

1. The combustion engine must have attained the necessary operating
   parameters (e.g. the minimum coolant temperature).
2. The relevant conditions relating to the vehicle must be met (e.g. sufficient voltage in the on-board electrical system, the interior climate has been regulated following the key start, the accumulator for the air suspension or brake system is sufficiently full). And the vehicle must be stationary, of course.
3. The relevant conditions relating to the driver must be met: the transmission selector lever must be set to D or N; no movement of the accelerator or the steering wheel; the driver's foot must be on the brake or the HOLD function must be active; the doors must be closed, the driver's seat belt must be fastened and the bonnet must be closed.
4. The ECO start/stop must not have been switched off via the ECO button.
5. Relevant speeds must have been exceeded after starting with the ignition key or during manoeuvring, for example.

Auto-starting takes place when the engine is in auto-stop mode, i.e. when the engine has been shut down via the engine-stop function and the ignition remains switched on. One of the following conditions must also be met:

• The accelerator pedal is pressed.
• Position "R" is selected on the transmission.
• The transmission selector lever is moved out of position "P".
• The brake pedal is released and Hold is not activated and the parking brake is released and the transmission selector lever is not set to "P".
• The ECO start/stop function is switched off via the ECO switch.
• The vehicle begins to roll.
• A function linked to running of the engine, e.g. raising of the ride height, is activated by the driver.

But the start/stop function can think beyond that: it is also able to start the engine automatically as an intelligent comfort and safety function. The engine control unit starts the engine automatically, without any intervention on the part of the driver, when one of the following conditions is met:

• A vehicle-related precondition for the auto-stop function, such as the conditions pertaining to air conditioning, the on-board electrical system, the brake system, the chassis and other vehicle-related influences, is no longer met.
• The driver releases his seat belt or opens the driver's door. Automatic starting takes place in order to prompt the driver to actively switch off the engine by turning the ignition key to position 0, prior to leaving the vehicle. This ensures that the ECO start/stop system is safely deactivated when the vehicle is parked.

 

[Gazwould]

Even a duff brake booster sensor prevents SS.

 

[markjay]

Even a duff brake booster sensor prevents SS.

True, however, when this happens, it flags-up a fault code on STAR (or iCarsoft).

The tough ones are those issues that do not flag-up a fault code, like a weak main battery. You can still diagnose it to some extent via the Start/Stop menu on the diagnostics device, which will show you which conditions 'have not been met'.