GRA with Separate Clutch Switch

Hi everyone, I'm new here.

I disconnected the clutch pedal switch on my PD150 ARL because it significantly improved the engine's responsiveness. Anyone can easily check this by briefly giving it some gas while stationary, both with and without the clutch pedal depressed.
The diagnostic tool VAG-Com also shows the error code.
Okay, now for the problem: Of course, my engine control unit (ECU) now thinks that I'm constantly riding the clutch (no error message is displayed), and therefore the gear range actuator (GRA) is no longer working.
Since I've come to rely on this feature and don't want to lose it, here's my question: How can I reactivate the clutch pedal switch when starting the GRA? The switch provides 12V.
All the lines from the GRA (presumably a piece of equipment) lead to the STG (likely another piece of equipment). Is it possible to tap into one of those lines to get a switching pulse that could be used to control a relay or something similar?

Hello,

Is the clutch pedal switch a normally closed or normally open switch?
If you have access, you could simply disable the GRA (Gearbox Ratio Adaption) by disconnecting the white wire (at least, that's the wire on my car... well, it's the pin that closes when the GRA switch's sliding switch is turned on). At least, on my GRA switch in my A3, the on/off switch functions share a common ground pin, which you can identify through measurement.
If you have a normally closed contact, you can, of course, reverse the function using a relay (single-pole changeover).
When the clutch is not depressed, the relay is de-energized, which provides power to the GRA switch. When the clutch is depressed, the relay is energized, which deactivates the GRA.

Best regards, Rainer.

Hello Rainer,

It's a bypass. But I don't want to disable the GRA; I want to re-establish the circuit of the K-switch when the GRA is turned on.
Do you have any ideas on how? Can I use one of the GRA lines to switch a relay? Do you switch a relay with 12V and ground?

Hello Felix, okay, now...

The current flowing through the GRA switch is not sufficient to activate a relay. Therefore, you need to tap into the 'on' wire of the GRA and first measure with a power operational amplifier (OP) whether it is connected to ground or 12V. You can then use the OP to activate the clutch switch via a relay.
This is also available as an electronic load relay, either as a complete module or as a kit for self-assembly.
Please get the latest Conrad catalog and look for a device with low standby power consumption (approximately 1mA).
Regarding the relay question: a "normal" relay has one or more control coils. When a voltage is applied to these coils (typically designs are available for 6, 12, 24, or 230V), a mechanical switch is activated (On/Off/Neutral).
"This control coil requires a relatively high current to generate a strong enough magnetic field to move the mechanical part of the relay; 1A might be sufficient for a car relay. This is, of course, much higher (a factor of 100 to 1000) than the control current in the GRA switch. That's why the extra effort is needed."

Best regards, Rainer.

I think you can change the setting from "switch" to "automatic." I don't think I'm the only one who knows this, but I don't know if it will help you with your problem? However, when it's set to "automatic," the setting means there's no clutch, so there's also no clutch pedal switch. }

I don't think that will work.

"Retuning the TCU (Transmission Control Unit) won't achieve anything because it will then cause the engine speed to remain constant during gear changes (as has been reported here)."

Since both the "Dämpfen" (presumably a type of braking or deceleration) and the GRA (likely a specific braking algorithm) are processed within the STG (likely a control unit), and the clutch switch connects directly to the STG and is used for both functions, you probably only have the option to choose between "SPONTAN" (presumably a spontaneous or immediate mode) or GRA.

m;

I disconnected the connector for the clutch pedal switch on my PD150 ARL because it significantly improved the engine's responsiveness. Anyone can easily check this by giving it a little gas while stationary, both with and without the clutch pedal depressed.

The function for this is called 'active surge damper' (active shock absorption), and its purpose is to prevent sudden, heavy loads from impacting the powertrain.

-> I would leave it in its original condition, unless you don't care about the mileage of the drive shafts (joints) and the transmission/differential.

CU Gremlin.

Wow, neuen Antworten zwei Jahre danach. Thanks, guys.
@Gremlin
You're absolutely right. However, I can also gently control it with my foot. I just don't want to feel disempowered and drive an agile car. Besides, a turbo engine doesn't unleash its power with brute force on its transmission anyway.
Things are quite different when it comes to high-volume suction devices.
I once read about acceleration tests conducted by a car magazine with a Diablo that had to be stopped because the drive shafts broke.

Hi,

I wouldn't describe the power of the TDI as not being very forceful.

Someone (maybe a Gremlin?) once posted a picture here showing the raw power that such an engine can unleash when you aggressively engage the clutch with locked wheels, modifications, and a lot of throttle.

Best regards,

Jan.

Jan6K wrote:

I once posted a picture here showing the raw power that such an engine can unleash, especially when you aggressively engage the clutch with locked wheels, modifications, and a lot of throttle. Best regards, Jan

So, with the BMW, the rear wheels will then spin .


@ Felix
Was the problem with the switch resolved, or have you been driving for 2 years without a GRA?

The picture below is awesome.

http://www.ralfhandel.de/images/gelenk.jpg

@Steffarn
No, with the rudimentary solution. A toggle switch that disconnects the clutch pedal sensor.

Regarding the issue of power: I have a book here called "Modern Diesel Technology." It describes the first TDI engine (1Z) that was used in the 24-hour race at Le Mans. Back then, Volkswagen had its own racing teams, and they always had problems with the power transmission. It was either the transmission, the clutch, or the axles that failed. Eventually, they reprogrammed the engine control unit and reduced the torque peaks to prevent further damage. And these weren't standard parts that were breaking. I just wanted to point out that you shouldn't underestimate the power output of a turbocharged engine.