Installing universal standalone GCU requires certain
modifications to be done to the mechatronics unit inside Getrag
GS7d36sg transmission.
To modify it You’ll need:
- Soldering
station
- Dremel /w abrasive plate
- Torx
- Side cutters
- 1mm2 and 0,35mm2 Wires (silicone/PTFE wires, oil resistant,
200C rated)
CAUTION: This modification require soldering experience
and steady hand due to very tight location of soldering
RECOMMENDATION:
please use NOISE SUPPRESION circuit that can be found at HTG e-SHOP
to minimize risk of signal noise. Circuit description can be found
at WIKI / WIRING / NOISE troubleshooting
Open DCT mechatronics
cover by unscrewing T25 TORX bolts around cover. Please keep in
mind that remaining transmission fluid may leak while opening the
cover.
- Disconnect main connector from mechatronics unit
by pulling plastic lock up, and pulling connector out.
- Unscrew round connector in gearbox housing. To remove
it completely use long tool to unlock and unplug connector from
temperature and input shaft speed sensor behind clutches. It is
also possible to remove front clutch dust cover to allow easier
access to the plug. i. Remove front dust clutch cover. ii. From
front of the trans you can clearly see Torx screw that holds ground
clip. Unscrew it. Pay attention not to drop the screw. iii. From
side pan location where the loom turns i to case connector insert
long screwdriver. Being in the front you have good visibility on
it. iv. Gently push on the connector from the TOP and pull the leads.
Remove wires from 4 pin connector and replace with new wires in
the following order (with respect to below diagram of pin numbering):
- pin 1 to GCU FREQ_in3 (B3)
- pin 2 to GCU s_GND (L2)
- pin 3 to GCU AN_in9 (E1) IMPORTANT: Add 2k2 pull-up
to +5v_out (M1)
- pin 4 not used.
It’s possible to connect this sensor without removing it’s connector
but it requires to label wires connected to original main connector (MC)
prior to cutting them. To do so label wires going to original MC
pins 4, 5, 6. OEM MC pin 4 is sensor’s pin3 (AN_in9), OEM MC pin
5 is sensor’s pin2 (s_GND) and OEM MC pin 6 is sensor’s pin 1 (FREQ_in3).
To remove
control unit unscrew all the bolts shown in the picture below (11
positions).
After removing unit 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.
Remove
plastic covers from solenoid connectors by gently levering.
- Unscrew T10 TORX bolts holding aluminum cover of electronic
control unit. Carefully remove rubber seal to avoid damaging it
at further modifications.
Pay attention to pad nomenclature and numbering order,
since correct wire routing is mandatory for transmission to function
with standalone HTG Gearbox Control Unit.
- Stock controller is connected to pads around it with
thin aluminum wire. Remove all of them with tweezers. While removing
pay attention to hold them as close to soldering pads as possible
so minimal length of them remains (preferably none).
- Clean solder pads MECHANICALLY. Degreaser / nitro / acetone
does not remove gel cover. Easiest way is to remove it with tweezers
and ear cleaning sticks.
Connectors A and B require additional cleaning with Dremel
type tool with abrasive disc to remove coating preventing soldering.
- Measure length of connecting signal (0.2mm2 or 24AWG)
wires that are needed to be done. Wires shouldn’t be too short to
avoid connection failure in future. Apply tin to tips of wires before
soldering on to pads.
Make sure there is no short to thin trace between pads C2 and
C3.
- Perform soldering listed below:
- E1 connect to A2
- E2 connect to B2
- E3 connect to C2
- E4 connect to C3
- E5 conncect to C4
- E6 conncect to C6
- E7 conncect to C8
- E8 keep unconnected
- E9 connect to C10
- E10 connect to C11
- E11 connect to C12
- Merge E12 and E13 and connect them to (D2,D3,D6,D7,F2,F3,F6,F7,F10,F11)
- E14 connect to C5,B1,A1
- E15 connect to C13,C9,C7,B3,A3
- After soldering ensure there are no short circuits between
pads. Apply silicone seal on solder pads, and on wires to prevent
them from moving around and avoid connection failure.
- Reinstall rubber seal before mounting the cover back.
- Tin all soldering pads on solenoid connectors. Each connector
has signal and VCC wire. It is recommended to wire all of them in
the same way, for example pad 1 signal and pad 2 VCC (+12v on ignition).
- Measure wires to be long enough to allow easy connection
outside of transmission. Label signal wires from 1 to 10. It is
crucial to label them reliably to minimize risk of incorrect wiring.
Each solenoid has to be connected to corresponding output of HTG
GCU unit. For ease of wiring solenoid consecutive numbers match
consecutive output numbers.
Photograph shows which pad has to be soldered
to PWR_out wire. Remaining pads are joined together with VOLTAGE
supply - Results from point 9l
- Connect solenoids with the GCU Skip to the end to see
HTG GCU pinout diagram
- Solenoid 1 to GCU PWR_out1 (H1) S1-A
- Solenoid 2 to GCU PWR_out2 (H2) S2-B
- Solenoid 3to GCU PWR_out3 (H3) S3-A
- Solenoid 4 to GCU PWR_out4 (H4) S4-B
- Solenoid 5to GCU PWR_out5 (J1) S5-A
- Solenoid 6 to GCU PWR_out6 (J2) S6-B
- Solenoid 7 to GCU PWR_out7 (J3) S7-A
- Solenoid 8 to GCU PWR_out8 (J4) S8-B
- Solenoid 9 to GCU PWR_out9 (K1) S9-A
- Solenoid 10 to GCU PWR_out10 (K2) S10-B
- Either apply tin to wire tips of main mechatronic connector
(MC), and prepare set of wires to solder to them in a way that total
length would match length of solenoid wires, or make new wires using
GS7 Main Connector terminals. Those terminals are available for
purchase from HTG. 20-18 AWG wires are used for terminals MC 1 -
12 while 15-13 AWG for MC 14-16. Terminal numbers are described
on the connector itself. See diagram below for confirmation.
- MC 1 to GCU AN_in1 (C1)
- MC 2 to GCU AN_in2 (C2)
- MC 3 to GCU AN_in3 (C3)
- MC 4 to GCU AN_in4 (C4)
- MC 5 to GCU FREQ_in1 (A3)
- MC 6 to GCU AN_in5 (D1) IMPORTANT: Add 4k7 pull-up
to +5v_out (M1)
- MC 7 to GCU FREQ_in2 (A4)
- MC 8 to GCU AN_in6 (D2) IMPORTANT: Add 4k7 pull-up
to +5v_out (M1)
- MC 9 can be removed
- MC 10 to GCU AN_in7 (D3)
- MC 11 to GCU AN_in8 (D4)
- MC 12 IS EMPTY
- MC 13 to GCU_+5v_out (M1)
- MC 14 to fused (25a) +12v supply[joined with GCU_+12V_main
(M3, M4) ]
- MC 15 to GCU_sGND (L2)
MC
16 to fused (25 a) +12v supply[joined with GCU_+12V_main (M3, M4)
]
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
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 (f.eg.Victor Reinz Reinzosil).
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 needs voltage feed.
For proper functionality HTG GCU needs to
be fed with ECU signals. Those signals are usedto configure and
map transmission operation.
To communicate with ECU AN_out1-4
(A1, A2, B1, B2) can be used and CAN_1 and CAN_2
This guide
is just INFORMATIONAL one. It shows quite easy and safe method of
wiringGS7d36sg 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.
Click here to see Interconnector pinnout