Coding Grand California

Many of you probably haven’t had any exposure to coding at all. If you’re not a techie or a gamer, you’ll probably stay that way 99 percent of the time. But maybe today we’ll change your mind on the subject a little bit.

From the ECU to the OBD connector…

A modern car, such as the Grand California, is nothing more than a moving computer. Many people don’t even realize how much technology goes into a vehicle like this. The vehicle electrical system control unit communicates with the alternator because, for example, the lamps are switched on and more current is now required. Or the engine control unit notices after a mountain pass that the engine oil is too hot and thus reduces engine power. You understand where we are going, an incredible number of components have to communicate and work together, that requires software. This software is stored on the individual control units and performs its service there. The Grand California alone has over 20 control units on board. Maybe it is now clear why the step, which is of course controlled by a control unit, sometimes makes a few zigs.

Now every car built since 2001 has a so-called On Board Diagnostic port, OBD for short. This port can be used to connect to the above control units with the appropriate hardware and software.

So, for example, if the engine control lamp lights up in your dashboard, we hope this will never happen, there is a fault. This error is stored on an ECU and can be read out via the OBD port . The workshop is thus able, thanks to the many hundreds of measurement data, to narrow down the fault and solve the problem.

… for coding

In addition to fault location, the ECUs can also be reprogrammed via the OBD port. For this purpose, there are many software programs on the Internet that can adjust the corresponding values. Programming or coding is necessary, for example, to tell the vehicle after a battery change that a new battery has been installed. This is important in this example so that the control units can correctly process the data received from the battery.

There are also quite a few options for customization through coding. For example, accessories that are actually subject to a charge can be activated in the Grand California, provided that the necessary components are installed. The most prominent example is the subsequent and free activation of the lane departure warning system, which Volkswagen pays a high price for ex works.

We would like to share two really important use cases with you in the following:

Conversion to lithium battery with the software Car Scanner

The first point is the conversion to lithium battery in the control unit. We had written about lithium batteries in our blog a few times, most of the lithium battery available in accessories have a charging current of 100A. This can cause limitations when simply replacing it in the Grand California, because the Grand California’s charging current is more than twice as high, with a peak of 200A. Certainly all modern lithium batteries have a BMS installed which blocks these currents and does not allow them to reach the actual battery cells. But the alternator must also always regulate, which over the years is probably not good for the battery, nor for the alternator.

Fortunately, there is a little trick here: with the Car Scanner app, you can switch the battery technology to lithium. This means that the control unit now knows that a lithium battery is installed in the vehicle. This change causes a limitation of the charging current to approx. 80A.

KFG Reset

You must have heard about the KFG plug, which is supposed to be pulled so that one or the other problem, such as a non-extending step, is solved again, right?

Now there are two possibilities: first you crawl into the passenger footwell and pull the KFG cable, which in the worst case can lead to damage to the control unit or secondly you restart the control unit simply and easily via your cell phone. Variant two sounds much better, doesn’t it?

Required hardware and software

As mentioned in the text above, you need hardware and software to perform the KFG reset, for example. Don’t panic – with about 40 Euros you can start coding and help yourself in the future, especially in problem situations.

The hardware is an OBD dongle from VEEPEAK, which you can buy at Amazon.

Buy here – https://amzn.to/40LYWT4

The OBD dongle from VEEPEAK is delivered without the necessary software, here is now a whole series of apps, which you can use. We have had good experiences with the Car Scanner app, which is available for iOS and Android. The app itself is free, but also has a Pro version that unlocks more features. The costs for the Pro version are 8 Euro.

KFG Reset with Car Scanner

In the following we describe the KFG reset with the help of Car Scanner. The adapter must be connected to the OBD interface of the Grand California and the ignition must be switched on.

1. Start the app and connect to VEEPEAK by selecting the “Settings” item.
   

2. Select the VEEPEAK in the settings under the item “Adapter”.
   

3. Select Volkswagen OBD-II (MQB) in the settings under the item “Connection profile”.
   

4. Select “Coding & Service” in the main menu.
   

5. Select the “Long coding” item and click on the “3D Special Function” control unit.
   

There you will now find Soft & Hard Rest. Both are used to restart the KFG control unit. Please always use the soft rest first, you can think of it as the normal reboot on your PC. However, if the control unit does not respond to this, use the Hard-Rest function. This is equivalent to the reset button on a PC.

The control unit then restarts and there is no need to disconnect the plug.

If you have any questions about VEEPEAK, Car Scanner or the manual. Just post it in the comments.