Introduction

The EA888 Gen 3 (EA888.3) is a global engine suitable for MLB (Modularer Langsbaukasten/Longitudinal ) and MQB (Modularer Querbaukasten/Transverse) platforms, capable of meeting the latest emission and fuel economy targets in different markets.

In the Europe, the new MQB EA888 Gen 3 engines were introduced to Volkswagen Golf, Skoda Octavia, Seat Leon and Audi A3/S3 vehicles.  There was a mid cycle update (face Lift) to the EA888.3 powered cars which included among other things the introduction of an updated gearbox. These EA888.3b engines were partnered with a 6 speed manual or the DQ381 (0GC) 7 speed DSG gearbox. The DQ381 has an all wheel drive variant as DQ381-7A, the front drive variant is called DQ381-7F.

The 7 Speed DSG transmission has two wet clutches bathed using concentric friction disks and clutch plates.  like other gearboxes once clutch is drives odd gear, the other drives even gears.  Clutch clamping force is delivered by clutch pressure which in turn is which is converted to duty cycle and controlled by solenoid current.

Clutch pressure is controlled in full time closed loop, while clutch pressure targets are set primarily by torque demand sent from the ECM.  The DQ381 transmissions are known to hold slightly more torque that the earlier DQ250 6 speed gearboxes and in stock form the torque is limited by the controller to around 370-400Nm in some calibrations. The physical limits of the transmission are not known with particular detail but the clutch patch appear to slip before the gearset breaks.

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The DQ381 has different drive modes, the main 3 modes are Drive (normal), Sport, and Tiptronic (TT). Depending on the vehicle configuration, there may be additional modes available, such as ECO (Economy), and ALT (High Altitude).

• Drive and Sport modes are the main influence on current gear choice. In these modes the DSG will choose the correct gear based upon

  • Axle torque

  • Throttle position

  • Engine RPM

  • Recent driving behavior / timed behavior changes. 

• Tiptronic Function (manual shifting) - Is selected using the factory paddles or by placing the shifter in the manual shifting (Tiptronic) position.  Within each of these drive modes there are more tables and logic to further define their function.

Programming and RaceROM

On the DQ381 there is no ability to add a RaceROM feature file to the software. At some point RaceROM will be added but until it the justification for RaceROM is achieved you do not need to patch a DQ381 ROM to program it into a DCG controller.

For information on how to program as well as flash recovery, check out.

NOTE: With all of the VW AG DSG’s gearbox adaptations must be completed after programming or it will not learn the new parameters to achieve clutch and line Pressures desired.

• ECU Programming Overview

• How to Recover an ECU
  
  

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For more software guides check out:

• Software Help and How-To

Clutch Learning and Adaption

After programming the TCM you need to reset the clutch adaptions on the DSG to make use of the increased setpoints and relearn the positions and duty’s for solenoids when different torque and pressure setpoints are used.

to complete DSG learning in ProECU simple open the DSG tools menu and reset the adaptions required.

Tuning the DSG

Tuning the DSG is generally includes

• Setting the adaption limits to allow for Increased clamp pressure at the desired full load engine torque.

• Remove Torque limitation & Rev Limits sent to ECM.

• Tuning the shift schedules, routines and times to makes shifts at the desired RPM in the set mode and improve the shift speed.

• No forced KD in manual mode & lower gears.

• Revise the kiss points for clutch engagement.

• Increased LC rev limit using TCU setpoint.

• Set up various other options such as run LC with ESP on in manual mode etc.

Our example ROM addresses these features so please use the example ROM guide to assist this document with specific setpoints and tuning methods.

VW AG DQ381 Example ROM Description

Example ROMs (Example_DQ381F_2019_Golf GTI PP 0GC20G_2404_enc.bin) are found here C:\EcuTek\Stock ROMs\Volkswagen\Mk7.5\DSG\DQ381 Example ROMs.

Torque

The most important parameter for the DSG is the Input Torque which is received over CAN from the ECM. You must have accurate torque estimation in the torque to air and air to torque maps in the ECM, see the ECM tuning guide on how to set these maps up (VW AG EA888 Engine Tuning | VWAGEA888EngineTuning AirflowDetermination).

There are several important functions that compensate torque as it is received in the TCM, it is then also limited and a torque request sent back to the ECM. If the torque limits in the TCM are not increased it will apply a torque limit to the ECM and reduce the power, hence why tuning VW AG platforms ECM and TCM tuning should always be performed together.

Its possible that there are functions that perform the following

Work is continuing to get more of information together to better explain the torque to pressure and pressure to current derivations and more updates to this documentation will be made at a later date.

Engine Torque Limitation (in and out)

The gearbox has input and output torque limitations for adaption and normal running, when tuning the gearbox these need to be addressed.

Torque Actual (& Efficiency) These maps also limit the torque actual for the clutches and should be raised to match the maximum input torque you are looking for

Torque Limit (Depleting & Efficiency) these map limit the input torque to the clutches and should be raised to accommodate the higher outputs and increase the calculated torque for pressure control.

• KreGr_KompAV_GewMMot_Max_kl - Maximum weighting via the engine torque to compensate for the displacement of the aggregate

• Torque Reduction After Driver Demand - Torque reduction after driver demand increase after a downshift or upshift, the input axis is Motor/clutch torque. In the example ROM this is decreased slightly.

• Upper Torque Limit for Motor Controllers - these values are used when coasting and were lifted to avoid and further limitation.

Clutch Torque

• Maximum Torque (clutch open) the maximum torque when clutch is open i.e. when a torque reduction is applied

• Maximum Torque (gearbox protection) maximum actual torque limitation for the transmission, this value is sent back to the ECM, in our example ROM it has been raised to 1000Nm.

• Maximum Torque (Launch Control) maximum torque setpoint while in Launch Control Mode, in our example ROM this is lifted to 800Nm

• Maximum Torque (temperature) when the temperature of the gearbox is high this limit will be applied. the limit is only applied if the temperature goes above the first temperature break point of the map.

• Maximum Torque Clutch 1 & 2 the maximum torque allowed used in the data variables function, this is expected to be limits for coding as well.

• Maximum Torque Rate of Change (Input Shaft Differential Speed) is the ramp rate at which the torque can increase based on the difference between the current input shaft speed and the clutch speed difference. In the example ROM the RPM axis has been adjusted to allow high torque ramp rates at higher speed differences.

• Maximum Torque Rate of Change (Launch Control) is the maximum allowed torque increase rate when in launch control mode. In the example ROM this has been raised.

• Maximum Torque Rate of Change is the absolute value for torque increase amounts based on torque in the X-Axis and Accel Pedal on the Y-Axis. in the example ROM the torque axis has been increased to allow higher ramp rates at higher torque targets

Torque for Clutch pressure

Torque Control in the TCM is used for ECM Torque limitation, Torque for target clutch pressure and Torque ramp Rate limitation. The target torque and to Clutch pressure appears to be set using a linear conversion calculation from 0 to maximum torque matched converted and matched from 0 to maximum Solenoid Current. this is why it is important to have the TCM delimited and the ECM set to deliver an accurate amount of torque over CAN.

Ramp Rate’s for Pressure during shifts are based on Macro and Micro slip controllers that appear to drive clutch current up and down depending on their specific requirements.

It is believed that is uses linear regressions functions to determine the relationship between torque transmission and pressure.

Clutch Adaptions

To achieve a target Pressure from a target torque gearbox adaptions are necessary to allow the gearbox to determine the relationship between torque pressure and slip. As noted above adaptions need to be performed after every programming change on the VWAG DSG’s otherwise the learnt settings may not match what is required.

Target Torque P4 1 & 2, this is the adaption maximum target torque used when learning the clutch pressures. These have been raised to 700Nm in our example ROM.

Target Pressure P4 1 & 2, this is the adaption maximum target pressure for the above maximum target torque used when learning the clutch pressures. These have been raised to 20Bar in our example ROM.

Clutch Pressure target Control

There are many Clutch pressure target limits but it is believed that the relationship between torque and pressure target is decided by the adaption functions. these adaption functions when triggered have multiple thresholds to start and continue with timers to stop the function from adapting correctly.

measure the clutch slip

Clutch Pressures Target

• Main Pressure Requirement - This is the main (line) pressure target required based on fluid temperature and x axis is gear selector position.

• Maximum Clutch Pressure for Actuator Movement - The maximum pressure for movement of the gear position actuators

• Maximum Allowed Clutch Pressure - this is the Maximum Pressure allow for Adaption of Pressure Kiss point calculation and basic measurements.

Leakage Compensation correction

As part of the clutch pressure control function the leakage of the clutches (past clutch seals etc) is estimated and accommodated in the pressure target and hence solenoid duty / current. This appears to be done using a closed loop controller that adds to the clutch pressure target.

• Clutch 1 & 2 Pressure Gain (Integral) - Integral factor for leakage amount

• Clutch 1 & 2 Pressure Gain (Proportional) - Proportional factor for leakage amount

• Clutch Pressure Offset - The offset value for the target pressure based on the estimated leakage amount

Clutch Pressure Target Adaption Limits

• Clutch Current Pressure Threshold - when the actual clutch pressure goes above this the target pressure is held during the adaptation process.

• Maximum Clutch Pressure Stage 1 & 2 - the maximum clutch pressure allowed when clutches are in the Open no propulsion states 1 & 2 during adaption

• Upper Pressure Limit Clutch 1 & 2 Characteristic - Upper range limit for characteristic curve adaption on clutch 1 & 2.

• Kus_PKupOfs_PKupZuKlein_ko - Clutch Pressure Offset?

Clutch Pressure Target Limiters, Diagnosis and safety function maps

• Clutch Monitor Pressure Threshold - Monitoring measured clutch pressure threshold If the pressure goes above this monitoring is triggered.

• Max ADC Value for Clutch Pressure - The maximum ADC reading from the pressure sensors in the clutch pressure diagnosis function

• Maximum Permissible Clutch Pressure - Max pressure in the main clutch and safety functions

• Maximum Pressure Clutch 1 & 2 - Global Max Pressure target

• Maximum Target Clutch Pressure - Clutch safety functions Maximum target pressure

• Ahd_PGetr_SchwellePKup_ko Adaption function Main pressure threshold at which the maximum clutch pressure is switched from stage 1 to stage 2 in the "No Propulsion open pressure" state

Line / Main Pressure Target Control

Main/Line pressure needs to be set to above the desired clutch pressures to ensure that there is enough headroom to deliver the clutch pressures from the main circuits. Line pressure uses a target and closed loop PID control strategy to maintain the desired line pressure.

• Oil Pressure Main - Target main pressure maximum when doing adaptions

• Target Main Pressure (OPL_3266) - Target main pressure maximum when doing kiss point adaptions

Solenoid Current Control

During adaptions its believed that a pressure target to solenoid current profile is developed and the pressure PID control and micro and macro slip controller functions are used to influence this pressure to current characteristic. To make sure that the solenoid current delivers learn the appropriate values the min and maximum values and initial values for adaption should be increased.

• Valve Current Compensation Max/Min - Clutch. The maximum and minimum solenoid current for Clutches.

• Valve Current Max - Clutch Coupling. The maximum allowable pressure target for the solenoid current for the Clutches.

• Valve Current Max - Clutch The maximum solenoid current for both CLutches.

• Valve Current Max - Gear adjuster. The maximum solenoid current for driving the gear shift actuation pressure circuits.

• Valve Current Max - Main Pressure. The maximum solenoid current for driving the line pressure circuits.

• Valve Current Max - Oil Cooling. The Maximum Solenoid Valve current of the electric oil pump used in cooling circuits

• Valve Current Max - Partial Transmission. Gear selector circuit solenoid valve current maximum allowed.

Gear Shift Control

The DQ381 has many different shift modes and shift settings, the primary Shift control functions are

• Shift schedules

• Forced Upshift and downshifts

• Shift time targets

• Pressure crossovers & torque reductions

• Kick down

The primary running modes for the gearbox are ECO (which is normal mode) and Sports mode, however tiptronic (TT), off-road, mountain, efficient and limps modes can also be found. As discussed previously it is generally accepted that for most cases the sports mode shifting and tiptronic setpoints are generally acceptable but the ECO (normal) driving modes may need adjustment.

Adjustments to shift schedules can be done in using a few different methods, some more in-depth than other, in this example a simple accel pedal axis and shift RPM changes were made in Drive mode, very few changes were made to ECO and Sport schedules as there are deemed to be OK.

Understanding the Shift Sequence

The DQ381 has a complex Gear shifting strategy, which includes multiple drive modes with individual shift points, limitations and shift timing for each of these running modes. Shift point and limits appear to primarily be chosen by drive modes (eco, sport, off road etc). Shift timing appears to have two primary selectors, the first is if the shift is using a torque reduction or not, and if its no torque reduction is present it then looks to see if the vehicle is in over run conditions (Push) or normal driving.

The below chart tries to illustrate the different parameters that go into making an Upshift for downshifts the target RPM and torque will be inverted.

Shift Schedules Adjustment

Adjustments to shift schedules can be done in using a few different methods, some more indepth than other, in this example a simple accel pedal axis and shift RPM changes were made in Drive mode, very few changes were made to ECU and Sport schedules as there are deemed to be OK.

Sadly ProECU doesn’t currently handle arbitrary text in map Axis value so the axis of the shift maps are currently numbered 1 to 21 and 1 to 14.

Where in actual fact the Axis values should look something like below (the same for all modes)

X axis values

Y axis values

To change the driving characteristics elating to when the car shifts many different approaches can be taken,

• You can manually edit the desired modes shift speed.

• You can use a blend map to generate a shift point based on what Sport and ECO map currently are set too using the COBB method (Volkswagen MQB 7 Speed DSG Tuning Guide)

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• You can multiply or offset the shift schedule maps using a similar set up to the way GTR is calibrated.

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How to use the DQ381 Shift Schedule Calculation sheet

If you wish to use the DQ381 Shift schedule calculation sheet to view and edit your shift points download and open the sheet above. This sheet has two tabs, the first is a display tab and the second is a tab that you can edit using basic formula or manually editing.

To use the sheet you first need to know the gear ratio final drive and wheel size (to be accurate to engine RPM), if your only looking for a difference for the shift start point then the ratio numbers etc are less critical.

From there you can copy (CTRL + ALT + C) the entire map into the excel page and the charts will show you the upshift and downshift speed points.

The Charts for upshift and downshift automatically update.

If your looking to adjust the shift points then you use the adjust shift points tab and copy the data from the shift schedule map you wish to adjust into the sheet and then manually adjust the or use the multiply/offset cells to set you new shift point.

You can view the new shift points and compare them to the original to see what you have changed, then when your happy you can copy and paste the data out of the correct shift schedule map back into the ROM (CTRLK + C & CTRL + V)

Forced Upshift and Downshifts

Forced Upshift and downshifts are set in the shift schedule category and are used to prevent engine stall by forcing a downshift and overrev by forcing an upshift. The forced up and down shift maps are 2D maps with shift type ( from which gear up or down).

Note: Once again ProECU cannot represent the X axis Rows with text data the values of the rows are as per below.

Forced Upshifts are set by vehicle speed for each shift number (i.e.1st to 2nd).

Forced Downshifts are set by vehicle speed for each shift number (i.e.7th to 6th).

The DQ381 Shift Schedule calculator also has a copy map with multiplier and offset to help know where the shift limits might lie.

Shift time targets

As previously shown the DSG controller appears to use shift time targets based on two primary selectors, the first is if the shift is using a torque reduction or not, and if its no torque reduction is present it then looks to see if the vehicle is in over run conditions (Push) or normal driving.

If a Shift is using a torque reduction it appears to use a delay time before the shift sequence applies the torque reduction. the time targets are believed to set the ramp rates for torque and pressure as well as the start points for crossover times etc. There are likely many other times delays and crossovers that are currently un named as time goes by EcuTek will update these notes and the map definitions to help with understanding.

Switching time in “Mode” & Push

These maps use gearshift as their input and difference in Target input shaft RPM (for incoming gear) to actual input shaft RPM.

Target Gear Change Time (Mode) & Alt

These maps use gearshift as their input and either

• difference in Target input shaft RPM (for incoming gear) to actual input shaft RPM.

• Accel Pedal position

It is believed that it uses the largest of these values at this time but this needs to be confirmed via testing.

Pressure crossovers & torque reductions

As part of the shift there are setpoints for clutch overlap time, this is the value that sets the speed at which the clutch torques start to apply torque and hence pressure to the incoming clutch and how quickly it ramps the torque and pressure out from the outgoing clutch.

The maps appear to be individual times set for each mode and each gear. There are also global compensation maps for temperature and mode specific minimum allowed overlap values.

Overlap times (mode Gear)

These use Clutch Input torque and Input Speed to determine the overlap time target

For Tiptronic shifts there are two sets of maps, one that uses the normal input speed axis and a second that uses accel pedal position. It is believed it takes the largest of these values for the overlap time.

There is a Clutch Overlap time Temperature Compensation which is blended with the selected map output based on the gearbox fluid temperature so at low temperatures this map will be used, at normal operating temperature the blend will be such that the normal shift overlap map is output is used.

Minimum Clutch Overlap Time can be used to limit the minimum target time for each of the listed modes.

Kick down

Kick down function in the DQ381 are controlled primarily in the shift schedule maps, with activation parameters being set in column 18 of the x axis.

there are also kickdown and bump up limits for braking

Kickdown Entry Points (Downshift / Upshift), these maps are used as the entry point for shift when the brake is applied.

Kick Down in TIP Mode Enable this is a selection switch for kickdown functions in TIP mode (Tiptronic). In our example ROM this is set to 3 which is disabled.

0 = KD also works during the Tiptronic function
1 = KD off in Tiptronic with HIGH accel pedal values
2 = KD off in Tiptronic with LOW accel pedal values
3 = KD off in TipTronic mode
4 = KD On for Downshift in ‘Tiptronic mode in Drive’
5 = KD On for Downshift with Tiptronic off in sports mode

Downshift or Kickdown Lockout Speed is the vehicle speed at which the Kick down request in normal mode or Downshift request for Tiptronic are ignored. the Y axis is Downshift type, the X axis is the change rate of the dynamic shift program

Minimum Pedal Position for Kickdown this value is the threshold to trigger a kickdown

Kickdown Speed for GearHold is the value at above which the gear is held before doing a kickdown. This does not normally need adjustment.

Kickdown Set Point in Max Accel Mode is the map that set the kick down point when in Luanch control mode or Max accel (Amax) mode. this value is set to 255 in our example ROM.

Clutch Stall Speeds, Kiss Points and Adaption

The VW AG gearboxes use clutch stall speeds to determine the point at which the clutches engage when driving off from a standstill. the RPM at which the cutches are fully engages is called the Stall Speed. To achieve the stall speed the kiss points need to be learned, the kiss points are the point at which the clutches start to transfer torque from the input shaft to the output shaft and are learnt when doing the gearbox adaption sequences. The point of take-off also has limitations for torque, pressure and current.

The stall speed maps are the first port of call for adjustments, the stall speed maps are set for each mode (Normal/Drive, ECO and sport) for select gears as well as tiptronic specific stall speeds for the same gear sets as the

Clutch Kisspoint learning thresholds

• Engine Torque Maximum for Activation

• Engine Torque Maximum for Deactivation

Miscellaneous

There are a few other items that may wish to be tuned or information on may be required for tuning the systems completely.

Engine Speed Limitation

there are a selection of engine speed limits that appear to either force an up shift or send an engine speed limit to the ECM. the exact nature has not been fully tested yet and more information should be available shortly.

Maximum Engine Speed # Gear ( , APP & EFF) these maps are an engine speed limit based on motor power factor in %

There is an untested map that looks like it affects the normalisation/scaling factor used in the DSP functions and may rescale this value to higher than 7650rpm. this is yet untested but if this value is set to 33 it may change the scaling of these limit maps to be 0-8415 so a value of 7650 in the map would actually be 8415. It is expected that this actually will effect the shift schedules as well so test with caution.

MOTDRZ_NORM_VARI = Adjust normalization for high-speed motor concepts
0 "0: standard normalization [30 rpm per LSB] 0-255 -> 0- 7650 rpm"
30 "30: as default"
33 "33: [33 rpm per LSB] 0-255 -> 0-8415 rpm"
40 "40: [40 rpm per LSB] 0-255 -> 0-10200 rpm"

VWAG abbreviation translations

DSP = Driving strategy - dynamic shift program

DAM = Gear Display.

RBB_ENABLE = "Enable downshift when braking"

AKK = Clutch Kisspoint Adaption

AKG = Coupling basic characteristic adaptation

AHD = Main Pressure Adaption

ASG = Automatic Shift Gearbox (electronic manual gearbox) or some form of shift schedule

KTM = Clutch temperature Model

LOEK = Leakage Compensation

GRD = Basic Measurement

KV = No Propulsion