Installation of an Adaptronic ECU for a Lexus LS400/SC400 1UZFE Engine

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Although documentation exists for installation for a Toyota Soarer (SC400), there are none specifically for a LS400 (Celsior) motor.

My particular application does not require retaining the OEM ECU; however if yours does, I recommend following the directions for the Soarer installation when referring to the section titled “Fooling the Factory ECU to eliminate fault code generation”.  Specifically the ignition and air flow directions.

The early LS400 wiring harness contains 4 plugs that connect to the OEM ECU.  According to the 1992 LS400 Electrical Wiring Diagram, these are referred to plugs A, B, C, and D.

Only some of these wires are actually needed to connect to the four plugs for the Adaptronic.

What we are looking for in the original LS400 wiring diagram are for these sensors, inputs, and outputs that are required for operation.  Here is each LS400 plug individually.

LS400 Plug A

PLUG

PIN

FUNCTION

COLOR

ADAPTRONIC

Standalone

Piggyback

 

1


IGSW

Black/Orange
       

2

STA
Black
       

3

NOT USED

4


VTA1 – TPS

Yellow

20 pin

10

Pin
swap
Tap

5

THW
– Water temp

Red/Blue

20 pin

17

Pin
swap
Pin
swap

6


OXL1

Black
       

7

EGR
Temp

Red/Green
       

8

KS
Yellow/Green
       

9

T1
– TE1

Red/Black
       

10

NOT USED

11

VC
Blue/Red

20 pin

19


Connect

Connect

12

B+
Black/Red

8 pin

1

Pin
swap
Tap

13

B1+
Black/Red

 

 

   

14

NSW
Black/White
       

15

NOT USED

16

THA
Yellow/Black
       

17


OXR1

Black/White
       

18

E2
Brown

20 pin

20

Pin
swap
Pin
swap

19

SPD
Violet/White
       

20

T2
– TE2

Red/White
       

21

NOT USED

22

E1
Brown

8 pin

4


Connect
Tap

 

Of the pins listed above, the following use the same pin type and can be swapped as seen below.

VTA1 (TPS signal)                             Water temp signal

B+ (+12V Ignition)                             E1 (Gnd)

E2 (TPS Gnd) and VC (TPS +5V) do not have the same pins and must be wired conventionally by soldering or so other means of secure connection.

 Some of the other plugs utilize the same pins as well and may allow for pin swapping.  Others must be direct connected due to the larger pin.  If you choose to piggyback with the OEM ECU because of your application, you will want to tap some of the connections instead of swapping the pins.  This is noted in the Standalone/Piggyback columns.

Please keep in mind this is only a recommendation.  Take the time to review the wiring diagrams for your specific application.

LS400 Plug B

PLUG

PIN

FUNCTION

COLOR

ADAPTRONIC

Standalone

Piggyback

1

NOT USED

2

NOT USED

3

NOT USED

4

MREL
Black/Orange

 

 

   

5


W-Check Engine

Yellow/Red

 

 

   

6

FPR
Green/Red
       

7

ACMG
White

20
pin

14

Pin
swap
Tap

8

FC
Green/Black
       

9

NOT USED

10

NOT USED

11

OXR2
Yellow

 

 

   

12

NOT USED

13

NOT USED

14

           

15

NOT USED

16

NOT USED

17

NOT USED

18

NOT USED

19

BK –
Stoplight

Green/White

 

 

   

20

KD
Green/Yellow

 

 

   

21

NOT USED

22

NOT USED

23

AC
Black
       

24

OXL2
Green
       

25

NOT USED

26

Batt
Black/Yellow

 

 

   

LS400 Plug C

PLUG

PIN

FUNCTION

COLOR

ADAPTRONIC

Standalone

Piggyback

1

IDL
Green

Optional / Not documented

2

IGF
1

Yellow/Green
       

3

KNK
1

Black

20
pin

15

Pin
swap
 

4

VF 1 Grey

 

 

   

5

IGT
1

Black/White

16
pin

2

Pin
swap
Pin
swap

6

G2+
Green

16
pin

10

Pin
swap
Tap

7

G1+
Black

16
pin

3

Pin
swap
Tap

8

NE+
Yellow

16
pin

11

Pin
swap
Tap

9

NOT USED

10

IGF
2

Yellow/Black

 

 

   

11

KNK
2
Grey

 

 

   

12

VF 2
Blue/Red

 

 

   

13

IGT
2

Brown/Yellow

16
pin

9

Pin
swap
Pin
swap

14

NOT USED

15

G-
White

 

 

   

16

NE- Red

16
pin

4

Pin
swap
Pin
swap

On Plug C, the IDL pin can optionally be used as one of the eight Dig in’s.  Also the G- and NE- are connected together in the harness, only one needs to connect to the Adaptronic, remove the other completely or wire G- and NE- together.

Also note the IGT’s.  If using as a piggyback, see Soarer install directions.

LS400 Plug D

PLUG

PIN

FUNCTION

COLOR

ADAPTRONIC

Standalone

Piggyback

1

NOT USED

2

NOT USED

3

NOT USED

4

STJ
Black/Red

 

 

   

5

ISC
4

Blue/White

16
pin

15

Pin
swap
Pin
swap

6

ISC
3

Green/Yellow

16
pin

16

Pin
swap
Pin
swap

7

ISC
2

Yellow/Red

16
pin

8

Pin
swap
Pin
swap

8

ISC
1

Green

16
pin

7

Pin
swap
Pin
swap

9

NOT USED

10

NOT USED

11

#20
– Inj 2/8

Black/Yellow

8
pin

8


Connect

Connect

12

#10
– Inj 1/7

Yellow

8
pin

7


Connect

Connect

13

E01
– Ground

White/Black

8
pin

3


Connect
Tap

14

NOT USED

15

NOT USED

16

NOT USED

17

STJ1
Black/Red

 

 

   

18

NOT USED

19

HT2
– O2 Heat #2

Yellow

 

 

   

20

HT1
– O2 Heat #1
Red

 

 

   

21

EGR
Solenoid

Green/Red

 

 

   

22

PR –
Pressure up

Yellow/Black

 

 

   

23

NOT USED

24

#40
– Inj 3/5
Blue

8
pin

6


Connect

Connect

25

#30
– Inj 4/6
Red

8
pin

5


Connect

Connect

26

E02
– Ground

White/Black

8
pin

2


Connect
Tap

For simplicity, I chose to use a standard GM IAT sensor and a standard GM 1 bar MAP sensor.  Their installation is also very easy.

For simplicity, I chose to use a standard GM IAT sensor and a standard GM 1 bar MAP sensor since both are cheap and easy to find.  Their installation is also very easy.  Based on the sensor resistance, I created values for the air temp calibration.  Not exact, but works pretty well.

For the Water temp sensor, I kept the OEM sensor and calibrated it to match.  I also used sensor resistance to match up values and this has work pretty well so far.

Air Temperature


Both of the temperature sensor calibrations are approximates and may need some adjustment based on your application

Water Temperature

Adaptronic Plugs

Update: For all 1UZFE owners, you have to install this specific UZFE Data into the Adaptronic before the ECU can work.

Do you have any questions? If so, please head over to the forums to get a quick answer or share your experience!

This is a freelance site with no support by huge companies.  I have been doing most of the R&D and technical write-ups by myself with my personal money and literally thousands of hours of my time.  I have taken extra steps to demonstrate in details how things are done.  Currently I am one of the few people doing Lexus V8 research and performance enhancement.  This effort comes from my personal love for this wonderful engine.  Most of the modifications are from trial and error. There's no cookbook for 1UZFE mods and its unknown territory for much of supercharger performance.  The parts, labor, web development and site hosting are 100% paid from my personal hobby money.  If you feel my efforts help you in any form, please do not hesitate to donate any amount of money to support this site. You have no idea how much I and the entire Lexus and Toyota community appreciate it!

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