Lexus GS450h Drivetrain

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GS450h inverter external connector

The Lexus GS450h is a hybrid vehicle. Their inverters are suitable and attractive for DIY EVs because of:

  • Good availability and price - an inverter and "transmission" can generally be purchased for less than £/€1000.
  • Durability. Toyota engineers appear to have made the inverters foolproof, many inputs and outputs gracefully handle fault conditions.
  • Respectable performance. Rated for a combined 250kW output.
  • Ease of repurposing. Emulating the original ECU seems reasonably feasible. The transmission is a similar size and layout to many RWD transmissions.

The Lexus GS450h (2006-2012 model years) has a variety of useful components inside the inverter package:

  • Two high power inverters, for the 2 motors MG1 capable of handling X(?) amps, and MG2 capable of handling Y(?) amps. [1]
  • A boost module to boost the 288v battery pack up to 650v as used in the Lexus (Note that voltages this high are not required for EV conversions).

For technical analysis of this unit, see pages 14-47 of this document: [2]

If you combine a LHD transmission with a RHD inverter (or vice versa) you might end up with a motor that is juddering, not spinning. IN this case you need to swap any two phase cables of both MG1 and MG2.

The inverter is capable of running at full speeds on pack voltages from approx. 280V upwards. The maximum allowable input voltage is 650V, so far, many have found that "standard" EV voltages of 300V-360V to be well suited.

Note that even though the inverter maximum voltage rating is 650V, a 650V battery pack is not required to run this unit. It is capable of excellent performance at lower voltages, such as the typical 300V-360V found in most EVs. However, there is the opportunity to use larger packs with this unit if required in your application.

Should a higher voltage pack be chosen in your application for any reason, the buck/boost converter can be used to power auxiliary equipment at its native voltage.

Weight: 40 lbs

Dimensions: 14" x 9-1/2" x 8-1/2"

Buck/Boost Converter

A buck/boost converter lives within the inverter housing, originally this is used to step up the 288V battery pack in the GS450h to the 650V for use in the inverter in the GS. (Note that this does not mean the inverter requires 650V to run, it is simply a maximum rating) For those using a 600+V battery pack, this converter can be used to step the voltage down to a more reasonable level to interface with chargers, DCDC converters, heaters, AC compressors, and other components which can be found in "regular" EV's (Tesla, LEAF, Volt, etc.).

This unit is rated at 30kW, making it unsuitable for traction power, but good for auxiliary devices.

Details on how to control the converter are here:

For technical analysis of this unit, see pages 14-47 of this document: [2]


GS450h inverter and transmission pinout

For technical analysis of this transmission, see pages 46 and onward of this document:[3]

The transmission contains two "Motor-Generator" units. MG1 sits at the front of the transmission, and interfaces with the internal combustion engine through a planetary gear set. For this reason, to obtain torque from MG1, the input shaft of the transmission must be locked in place. This is usually done using a splined coupler, which is then welded onto the transmission front mount.

The input shaft on the transmission has 21 splines, with a 28mm major diameter. It is believed that there are several Toyota clutches which will have this in their centre. The original GS450h flywheel and coupler also contains the appropriate splined centre, of course.

The fluid fill port is the banjo bolt for the upper transmission cooler hose. The specified fluid is "Toyota WS" ATF.

It is a good idea to replace the two bearings in the electric oil pump before fitting a used transmission. There is a guide here[4]. Bearing part numbers are 61900-2Z and 608-2Z, you will need one of each.

GS450h shift position sensor

The shift position lever on the right-hand side of the transmission engages the parking pawl when in the "all-the-way-back" position. All other positions disengage this pawl. The R, N, D, M positions only affect the output of the shift position sensor.

Note the following when purchasing the transmission:

  • It is recommended to purchase one which has the electric oil pump fitted - these are a costly item as the bearings in them often fail, in some cases they cost more than the transmission. More on this in the Oil Pump section below.
  • It is recommended to purchase a transmission which includes the wiring harness, or at least off-cuts of the connectors. Some connectors may be unavailable for purchase. There is a thread here which covers the connectors on this transmission.


  • Overall height (oil pan to top of bellhousing) is 39cm. Bell housing is full height, i.e. 39cm diameter, when the transmission is sitting on its oil pan (as it is on my bench), the bellhousing still just about touches the bench.
  • Widest point is 40cm, includes a bump for a starter motor which I don't believe the GS450h even has. Likely leftover to mate with the 2GR engine.
  • Overall length including tailshaft, output flange, and pilot shaft, is 82cm.
  • Transmission is tapered quite heavily, the width and height is closer to 25cm after the bellhousing, but hard to gauge due to various outcropping parts (motor cables, oil pump, PRNDL selector, etc.)
  • Weight is 128kg. Unknown if this is dry or filled. Likely partially filled. Unknown if this includes oil pump and cables.
  • The input shaft pokes out 29mm from the general highest point of the back of the bell housing? (e.g. set a 20cm ruler there and measure from it)
  • The taper at the tip of the shaft before the splines appear fully is 6mm long. (i.e. the length of the tip portion without proper splines)
  • The output flange bolt pattern is 52.5mm radius (about 91mm from hole to hole). It does not seem to have a machined flange surface, only the 22.5mm diameter ~3.2mm deep recesses around the bolt holes are machined. Pilot shaft diameter is 16mm. Internally the flange has 26 quite rectangular splines. (not 27 or so like Toyota's more common off-road applications).

Oil Pump

Overview and location

reference image showing the pump fitted (green), and not fitted red)

As built, the GS450h supplies oil pressure to the gearbox using either the ICE engine or an electrically-driven external pump. With the input shaft locked in EV applications, the external pump is the only option available. As mentioned previously, this is a vital part of the setup and it's strongly recommended to buy a transmission that still has it fitted. To help with this, here is a reference photo of what to look for.

Wiring and control

GS450h oil pump controller

The external pump also requires a controller, which uses a PWM control scheme. Although this is rarely included with the transmission, it's quite affordably and widely available (Toyota part number: G1167-30020)

Pinouts, schematics and notes
  • The metal case is the ground.
  • Black (pin 6) is PWM in from your controller.
  • Brown (pin 7) is PWM feedback from the oil pump. It is not required and can be left disconnected.
  • The fat blue wire (pin 5) is 12V power. The oil pump uses around 50A Max. So plan for that. Add your own relay to stop it draining your battery while the car is off.
  • The PWM for this is weird, it's not just 0-100. IIRC it is 0% at both ends, and rises to 100% near the middle, then back down again. This is just based on the sound of the pump with no load, so needs more testing to find the real values.


As per ggeter: "For those, like me, who didn't get the pump with the transmission unit, here are the part numbers for bolts and (what appears to be a metal) gasket."

Bolts (4) 90080-10197 $2.76 ea.

Gasket (1) 35142-30010 $14

The oil pump also contains 3 black rubber O-rings:

1 x 55mm internal diameter, 2.5mm cross section (for the black outer cover)

2 x 50mm internal diameter, 2.5mm cross section (between each 'layer' of the pump housing).

The oil pump motor cover is held onto the pump housing by 4 M5 x 16mm flanged screws.

Wiring Harness Connectors

Here are a list of connectors required for the GS450h transmission & inverter if you need/wish to build the harness for your build. (It is a good idea to find components with at least the connectors to build on. As some of the connectors are impossible to obtain)

Inverter Connectors


Connector Toyota Part No. Location Terminals QTY Terminal Size Opt 1 Terminal Size Opt 2 Terminal Size Opt 3 Notes
Inverter interface connector (A62) Toyota


Black connector on the side of the inverter. This connector is not sold anywhere to our knowledge.

The information on the right is if the housing could be sourced.

0.64 36 - Female .13 mm2 / 26 AWG .22-.35 mm2 / 24-22 AWG .5 mm2 / 20 AWG
Sumitomo 8240-0336 (Tin) Sumitomo 8100-3455 (Tin) 8240-0287 (Tin)
Sumitomo 8240-0337 (Gold) Sumitomo

8100-3456 (Gold)

8240-0288 (Gold)
2.3 II 4 - Female .3-.5 mm2 (22-20 AWG) .5-1.25 mm2 (20-16 AWG) 2.0 mm2 (14 AWG) 6mm Pitch Type

(Low Insertion

Force Variant)

8100-0460 - (Tin) 8100-0461 (Tin) 8100-0462 (Tin)
8100-1344 - (Gold) 8100-0594 (Gold) 8100-0817 (Gold)


A good alternative to this otherwise difficult to obtain connector is to replace the receptacle/header with the following parts from Molex:

Molex MX123 series
Image Part No. Item Quantity
036638-0002 CMC header connector 48pin 1
064320-1311 CMC receptacle 48pin 1
064320-1301 CMC wire cap 1
064323-1039 CP terminal 4
064322-1039 CP terminal 32
064325-1010 CMC plug 8
064325-1023 CMC plug 4
Assembly Instructions

Instructions on how to assemble the MX123 connector can be found here [5].


Use the following pinout to remap the internal connections from the Toyota plug to the Molex plug:

GS450h Inverter/converter internal connections

Transmission Connectors

GS450 transmission main connection locations
Connector Toyota Part No. Part No. Terminals QTY Terminal Size Opt 1 Terminal Size Opt 2 Terminal Size Opt 3 Location
ECT Solenoid (E83) Toyota 90980-12326 Sumitomo 6189-1092 TS 025 Series


Female - 13 .13 mm2 / 26 AWG .22-.35 mm2 / 24-22 AWG .5 mm2 / 20 AWG Located on the left hand side of the transmission above the oil pan.
Sumitomo 6189-1092.jpg
Sumitomo 8240-0336 (Tin) Sumitomo 8100-3455 (Tin) 8240-0287 (Tin)
Sumitomo 8240-0337 (Gold) Sumitomo

8100-3456 (Gold)

8240-0288 (Gold)
Shift Lever Position Sensor (E80) Toyota 90980-12362 Sumitomo 90980-12362 TS 025 Series (0.64)

Female - 7 20-22 AWG /

.3-.5 mm2

16-18 AWG /

.85-1.25 mm2

14 AWG / 2.0 mm2 Located on the right side of the transmission next to the shift lever inhibitor switch.
Sumitomo 90980-12362.png
Yazaki - 7116-4025 (Tin) Yazaki - 7116-4026 (Tin) Yazaki - 7116-4027 (Tin)
Yazaki - 7116-4028-08 (Gold) Yazaki

7116-4029-08 (Gold)

TS 090II Sealed Series

2.3 II

(6mm LIF variant)

Female - 2 .3-.5 mm2 (22-20 AWG) .5-1.25 mm2 (20-16 AWG) 2.0 mm2 (14 AWG)
8100-0460 - (Tin) 8100-0461 (Tin) 8100-0462 (Tin)
8100-1344 - (Gold) 8100-0594 (Gold) 8100-0817 (Gold)
MG1 & MG2 Resolver(s) (E81 & E82) Toyota 90980-12520 Sumitomo 6189-1240 TS 025 Series (0.64) Female - 8 .13 mm2 / 26 AWG .22-.35 mm2 / 24-22 AWG .5 mm2 / 20 AWG Two connectors located on the left side of the transmission by the bell housing.
Sumitomo 6189-1240.jpg
Sumitomo 8240-0336 (Tin) Sumitomo 8100-3455 (Tin) 8240-0287 (Tin)
Sumitomo 8240-0337 (Gold) Sumitomo

8100-3456 (Gold)

8240-0288 (Gold)
Vehicle Speed Sensor Connector Toyota # 90980-11153 [?] S-1530 [?]

Standardized TS Series Seals and Plugs For Harnesses
TS 025 Series Seal Plug
Wire Insulation Dia. Color Part Number Color Part No
TS 025 SL1 0.85-0.95 mm (.033-.037 in) Light Brown 7165-1423 Grey Toyota 90980-09871
TS 025 SL2 0.95-1.05 mm (.037-.041 in) Green 7165-1043 Grey Yazaki 7158-3043-40
TS 025 SL3 1.1-1.4 mm (.043-.055 in) Violet 7165-1312
TS 025 SL4 1.4-1.5 mm (.055-.059 in) Dark Yellow 7165-1198
TS 025 SL5 1.6-1.7 mm (.063-.067 in) Red Violet 7165-1199
TS 090 II Series 1.4-1.8 mm (.055-.071 in) Blue 7158-3006-90 Yazaki 7157-8761
2.0-2.2 mm (.079-.087 in) Grey 7158-3007-10
2.3-2.7 mm (.090-.106 in) Brown 7158-3008-80

Oil Pump & Oil Pump Motor Controller

Connector Part No. Location
Oil Pump Temperature Sensor Sumitomo 6189-0175 The connector is the small 2-pin connector in the middle of the harness between the oil pump and controller
HVECU -> Oil Pump Controller (A52) Toyota 90980-12483 Single large (7-way) connector on the side of the oil pump controller

Control Schemes

ZombieVerter VCU

As of 2022, the preferred solution (and the only one under active development) is the ZombieVerter VCU