Expand GRA on 1Z

Hi.

While studying the label file for the 1Z STG 028.906.021 (AF) control unit, I noticed that in group 6, field 3, there are bits that represent functions which are not possible with the GRA (Gearbox Control Unit) in the Golf 3 (especially delaying!).

Are there any pins on the MSTG (presumably a microcontroller or similar device) that would allow for implementing a delay using switches?

Is the MSTG "more modern" than the levers?

m;

Hi,

As far as I can dimly recall, this function was not originally intended to be implemented in software within the engine control unit (ECU).
The switching function (slower) can be detected by the TCU anyway.

Quote:

The switch function (slower) can, in any case, be detected by the TCU.

And which one is the "slower" pin?

In the circuit diagram, there are only the following functions:

on/off
Set.
resume

Thank you.
m;

Hi,

You don't need a separate PIN for this; the control unit is activated via the "Resume" function. When GRA (presumably a specific feature or mode) is enabled, a longer press of the "Resume" button initiates a speed reduction.
I once drove a Vento TDI owned by an American, and that feature worked on it, but it wasn't active/programmed on the ones sold in Germany. I think the software in the control unit (ECU) is responsible for that.

For me, the controls are: SET (-) for decreasing, RESUME (+) for increasing, and CANCEL (on the steering wheel).
and also, add a switch for ON/OFF to the turn signal lever.

The CANCEL function is not assigned on most toggle switches or shares the function with ON/OFF. The CANCEL function temporarily deactivates the GRA (presumably a system or device). This is useful in short 80-meter bands.
More recent toggle switches have a tactile contact; when you slide the switch towards the 'OFF' position, it provides a canceling action.

'+' and '-' functions work, although the software is responsible for this and it's not ideal. When using these functions, the anti-jerk feature is disabled, which makes acceleration quite abrupt. Deceleration is too slow...


CU Gremlin.

Gremlin wrote:

At my place, we have SET(-), RESUME(+), and CANCEL

.

Hi Gremlin,

With the G4 base, the GRA function works in the opposite way compared to the 3-series; the "+" function is implemented via the "SET" button.

Quote:

With the G4 base, the GRA functions exactly the opposite way compared to the 3-series

.

... and "Cancel" is the clutch for me (otherwise, there's nothing else for it, except the brake).

Because turning it off erases the memory .

I've been considering assigning the clutch shifting function to the button on the MFA lever (meaning I would have to buy the lever, as I don't have an MFA).

Until then, I've been doing pretty well, managing to press the clutch lightly enough that it neither disengages nor slips, but with the traction control (GRA) deactivated.

m

Hi Martin,

I use the brake to activate the "cancel" function... a very light tap just makes the lights flash briefly and turns off the GRA (Garage Door Opener). The switch on my unit is permanently set to "on."

The "kickback" or "jerk" seems to be present in the ASV as well, as mentioned above. When using the "+" setting, it's quite noticeable, and it likely operates at a level close to full power if you hold it for a longer duration.

"- is also too slow for me, especially because you have to press it for a whole second first."

Here's what else the Ibi can do: A short tap on the SET or RES button while GRA (speed limiter) is active will increase the speed by 1-2 km/h, and this happens instantly. Double-clicking will increase the speed by double, etc. This is also very useful.

Best regards,

Jan.

Here's what else the Ibi can do: A short tap on the SET or RES button while GRA (speed limiter) is active will increase the speed by 1-2 km/h, and this happens instantly. Double-clicking will increase the speed by double, etc. This is also very useful.


'Mine does too, but it's almost unusable; the steps are so tiny. By the time I managed to click on the tempo, it was already too late .'

@bertil

I just checked again. SET(-) and RES(+), regardless of whether it's a switch or an MFL.
'It is explicitly mentioned that the system can be temporarily (CANCEL) disabled by moving the switch to the intermediate position between ON and OFF. 'The switch will then return to the ON position.''

CU Gremlin.

Gremlin wrote:

...I just checked again. SET(-) and RES(+), whether it's a switch or an MFL.

Yes, that's correct (for the G4 and related models), but the original thread was about the G3, and on that model, the SET button is assigned to the "+" function.
I drove the 3-series for long enough, and I'm still having problems with the different button layout on the 4-series. It's really just a matter of software.

Based on your description, it seems you have the "older" switch. I already have the newer one with the rocker switch.

In the newer versions, the "cancel" option is no longer available; it's either on or off.

Regarding the G3 GRA:

I always cancel the GRA (automatic emergency braking) using the brake pedal because I've noticed that the switch for the control unit isn't the same as a regular switch.
'If I press the clutch pedal even a little bit, I immediately feel a jolt, which is more or less unpleasant and travels through the entire drivetrain...'
The power is not disconnected at all; you only need to press 2-3 mm on the coupling. Subjectively, it feels like the control unit immediately reduces the entire fuel injection amount.
What could that be?
I once thought that the might function more as a protective measure to prevent the engine from over-revving without load? }
'It's also interesting to note: if you have the GRA (Gear Range Adaption) activated and then carefully take the car out of gear with a light load without using the clutch, the engine will initially rev up slightly, but after about 2-3 seconds, the TCU (Transmission Control Unit) detects this and intervenes.'

Best regards,

Okay, and now consider why VW writes in the manual that the GRA (Gear Recognition Assist) should not be used without engaging a gear. Could the jolt be caused by the torque cutoff? The act of depressing the clutch surely deactivates the GRA, puts it back into standby mode, and puts the engine into overrun mode.

Best regards, WarLord.

@WarLord

Okay, I understand that much, but why is there a jolt when I press the clutch, and why isn't there a jolt when I press the brake? (This isn't just happening to me; I've also noticed it in an Audi 80 1Z.) That's exactly my question...
'I find the disengagement aspect interesting because I wonder how the control unit (ECU) detects when a gear is engaged and when it's not. It must recognize that if the traction control (TCS) is active, it's abnormal if the engine speed changes by more than x% within a second, and then the TCS is deactivated. It's clear that disengaging the clutch isn't normal operation; I just did it out of curiosity. If the ECU were 'dumb,' it would likely rev the engine up until it explodes (in order to maintain speed) in that situation.'

Best regards.

Capernaum.

Based on your description, it seems you have the 'older' switch. I already have the newer one with the rocker switch.

I have the third option: just with an ON/OFF switch. Everything else is on the steering wheel.

CU Gremlin.

WarLord wrote:

So, and now ask yourself why VW writes in the manual that the GRA should not be used without engaging a gear? Could the jolt be caused by the torque cutoff? Doesn't depressing the clutch cause the GRA to be deactivated, return to standby, and the engine to switch to torqueing mode? Greetings, WarLord

.

Hi,

You could also remove the gear lever without pressing the clutch.

Best regards,
Munch.

@Mampf

Kapernaum has removed the clutch and is now driving without it!

And the engine control unit (ECU) detected it because the engine speed became too high and the speed decreased.