VW DSG DQ500 gen.1 Wiring Guide

Installing universal standalone GCU requires certain modifications to be done to the mechatronics unit inside VW DSG DQ500 gen.1 transmission.

Actual for 1.0.9b-6 release

To modify it You’ll need:

CAUTION: This modification require soldering experience and steady hand due to very tight location of soldering



After removing unit from valve body it is strongly recommended to degrease whole assembly to improve ease of modification and keep your workplace clean. Universal degreaser works just fine as well as brake cleaner or so.

  1. Remove solenoid connector plate and drill rivets holding stock TCM cover.



  2. Remove plastic covers of flat flex cables and break welded connections.



  3. Remove aluminum cover of stock TCM. Make sure to do it carefully to avoid damaging flex cables and sensors.

    Next steps will require you to solder several wires. Please use quality wires that are designed to work in such environment. Oil and chemical resistance as well as 200 Celsius degree rating are strongly recommended.



Perform following connections:

  1. 1. A1, B1, C1, D1, E1, F1 connect together and then to GCU +5v_out (M1)
  2. A2, B2, C2, D2, E2, F2, G1 connect together and then to GCU s_GND (L2)
  3. A3 connect to GCU AN_in1 (C1)
  4. B3 connect to GCU AN_in2 (C2)
  5. C3 connect to GCU AN_in3 (C3)
  6. D3 connect to GCU AN_in4 (C4)
  7. E3 connect to GCU FREQ_in1 (A3)
  8. E4 leave unconnected.
  9. F3 connect to GCU FREQ_in2 (A4)
  10. F4 leave unconnected.
  11. G2 connect to GCU FREQ_in3 (B3)
  12. G3 connect to GCU +5v_out (M1)
  13. G4 connect to GCU AN_in9 (E1)


IMPORTANT: Add 2k2 pull-up to +5v_out (M1) on GCU end of loom.



  1. 1. Solenoid +12V SUPPLY
  2. 2. GCU PWR_out1 (H1)
  3. 3. GCU PWR_out2 (H2)
  4. 4. GCU PWR_out3 (H3)
  5. 5. GCU PWR_out4 (H4)
  6. 6. GCU PWR_out5 (J1)
  7. 7. GCU PWR_out6 (J2)
  8. 8.Solenoid +12V SUPPLY
  9. 9. Solenoid 7 to GCU PWR_out7 (J3)
  10. 10. Solenoid 8 to GCU PWR_out8 (J4)
  11. 11. Solenoid 9 to GCU PWR_out9 (K1)
  12. 12. Solenoid +12V SUPPLY
  13. 13. GCU PWR_out10 (K2)
  14. 14. Not in use

  1. Check if all soldering connections are good quality and then secure all of those points with silicone packing to protect it from short circuits.
  2. Wire “Solenoid +12V SUPPLY” to switched IGNITION (voltage has to be present when HTG GCU device is powered on). Circuit needs to be able to provide constant 25AMP.

    Pressure Sensors have solder pads labeled: VCC, SIG, GND.Stock controller is connected to pads around it with thin aluminium wire.



  3. Remove all wires with tweezers. While removing pay attention to hold them as close to soldering pads as possible so minimal length of them remains (preferably none).
  4. Solder Wires:
    1. PS_pad 1 to PS_A VCC and PS_B VCC ( later GCU +5v_out (M1) )
    2. PS_pad 2 to PS_A SIG ( later GCU AN_in7 (D3) )
    3. PS_pad 3 to PS_B SIG ( later GCU AN_in8 (D4) )
    4. PS_pad 4 to PS_A GND and PS_B GND ( later GCU s_GND (L2) )

    Those connections allow to transfer signals outside of stock TCM’s box. Follow easily visible traces on FLAT FLEX cables and connect according to above instructions “(later ...)”Keep in mind that s_GND and +5v_out connections are common for mentioned earlier sensors so can be joined together on various points.

  5. After soldering ensure there are no short circuits between pads. Apply silicone seal on solder pads and sensors, and on wires to prevent them from moving around and avoid connection failure, as well as to protect from potential transmission fluid influence.
  6. Reinstall rubber seal before mounting the cover back and reapplying rivets. Cover has to be sealed - if transmission fluid would enter to inside of pan pressure sensors may get damaged.
  7. It is STRONGLY RECOMMENDED to separate loom of valves from sensor loom, so noisy wires are not braided with noise vulnerable sensor signals. It is also recommended to put all wires in heat shrink sleeves inside transmission case to maximize protection.
  8. OEM round connector will only be used as a passage through transmission case - please drill a hole in it and lead all the wires through it and seal it with silicone packing afterwards (eg. Victor Reinz Reinzosil).

    There are numerous aftermarket round connectors fitting OEM connector sleeve - it is recommended to use such connector in order to have easily disconnectable internal loom from external patch loom.

    This guide is just INFORMATIONAL one. It shows quite easy and safe method of wiring VWDQ500 transmission to work with HTG GCU, but it can be also done with different method as long as connections remain unchanged between point and GCU.

HTG GCU requires main (MAIN RELAY’ed) battery +12v applied to +12_const (M3, M4), as well as ignition +12v signal applied to +12_IGN (L1).

Even though HTG GCU has internal protection it is advised to secure IGN signal with 5Afuse to prevent failure of the device.

Ground connections GND (L3 and L4) should be made on engine or chassis, as long as chassis ground point is confirmed to be efficient.

+12v_out (M2) can be used as supply for shifter, paddles or other low power auxiliaries that need voltage feed.



For proper functionality HTG GCU needs to be fed with ECU signals. Those signals are used to configure and map transmission operation.To communicate with ECU AN_out1-4 (A1, A2, B1, B2) can be used and CAN_1 and CAN_2CAN bus has to be terminated with 120ohm resistor.

Click here to see Interconnector pinnout
Parent topic: HTG Standalone transmission wiring