Audi, VCDS coding

Audi A4 B8 – Disable Auto Stop/Start

Posted on by bogdan
02
Oct

What is the Automatic Stop/Start System ?

  • In modern cars, a start/stop or stop/start system automatically turns off and restarts the internal combustion engine to reduce the amount of time the engine spends idling, thereby reducing fuel consumption and emissions.
  • This is useful for vehicles which spend significant amounts of time waiting at traffic lights or frequently come to a stop in traffic jams.
  • Fuel economy gains from this technology are typically in the range of 3-10 percent.

Why would you disable it ?

Because:

  • 1. it increases wear for engine internals.
  • 2. it increases wear for the car battery.
  • 3. it increases wear for the starter motor.

Let me explain:

1. it increases wear for engine internals due to lack of oil lubrication.

One of the most delicate moments for an internal combustion engine is the Start Up.
This is due to the fact that many components don’t have the correct lubrication.

Crankshaft

For the crankshaft bearing half shells and the big end bearings this can translate into frequent high-speed rotary movement before a hydrodynamic film is established.

During this phase of boundary lubrication, metal-to-metal contact can occur between the crankshaft surface and the bearing’s sliding surface.

2. it increases wear for the car battery.

Audi A4 B8 AGM
Start-stop systems are heavily reliant on the battery.
And yes on the Audi A4 B8 we have a nice and expensive AGM battery.

Just take a look at the prices . Varta AGM 105Ah.



This might be a problem for those of us that take short drives.
In a 10 … 15 min trip the battery does not have time to change.


I personally use a Cteck AGM charger and charge it from time to time.


Right now my battery has 7 years and it is still holding power.

3. it increases wear for the starter motor.

On this topic I will not insist.
The more you use something the bigger the chances for it to fail.

How do you Disable the Auto Stop function?

    These are your options:

  • you press the Auto Stop Button each time after you start your engine
  • using VCDS you change the default setting for the system to off. Now when you click the Auto Stop button you will activate it.

  • you do not use your seatbelt

What is the VCDS coding to Disable the Auto Stop Start on the Audi A4 B8?

  • connect VCDS cable to OBD port
  • turn ignition ON
  • start VCDS
  • select 09 – Central Electric
  • do the Security Access log in with 20113
  • select Adaptation
  • go to Channel 34
  • read value and change from 4 to 0
  • if your value is different subtract 4 from it
  • Test & Save
  • Done, Go back
  • Exit VCDS
  • Disconnect VCDS cable

    • Now when you start your engine the Auto Stop Start Witch should have the LED ON.
    This means that the system is off until you press on it and reactivate it.
    The default on stat will be OFF.

    bogdan