Body Electrical. Lexus Gs430, Gs300. Uzs190 Grs190
Meter. Lexus Gs430, Gs300. Uzs190 Grs190
Meter / Gauge System -- Terminals Of Ecu |
CHECK COMBINATION METER ASSEMBLY |

Symbols (Terminal No.) | Wiring Color | Terminal Description | Condition | Specified Condition |
IG (L31-1) - Body ground | R - Body ground | Engine switch signal | Engine switch off | Below 1 V |
Engine switch on (IG) | 10 to 14 V | |||
TURN (L31-2) - Body ground | G - Body ground | Turn signal L | Engine switch on (IG), turn signal LH indicator light OFF | Below 1 V |
Engine switch on (IG), turn signal LH indicator light ON | 10 to 14 V | |||
TURN (L31-3) - Body ground | O - Body ground | Turn signal R | Engine switch on (IG), turn signal RH indicator light OFF | Below 1 V |
Engine switch on (IG), turn signal RH indicator light ON | 10 to 14 V | |||
MPX (L31-5) - Body ground | SB - Body ground | Multiplex communication circuit | - | - |
CHK E/G (L31-8) - Body ground | R - Body ground | MIL | MIL ON | Below 4.2 V |
MIL OFF | 10 to 14 V | |||
4P (L31-9) - Body ground | LG - Body ground | Speed signal (Output) | Engine switch on (IG) and turn the wheel slowly | Pulse generation (See waveform 2) |
P SEAT BELT INPUT (L31-11) - Body ground | R - Body ground | Seat belt condition signal (Passenger side) | Passenger seat belt indicator is OFF | Below 1 V |
Passenger seat belt indicator is blinking | 10 to 14 V | |||
MODE CHANGE SW (L31-15) - Body ground | B - Body ground | Steering pad switch signal | Mode change switch OFF | Below 1 V |
Mode change switch ON | 10 to 14 V | |||
PH (L31-16) - Body ground | W - Body ground | Sunlight sensor signal | Meter is starting up | 1 to 3.8 V |
PH GND (L31-18) - Body ground | R - Body ground | Ground | Always | Below 1 Ω |
FUEL SENDER FE (L31-19) - Body ground | Y - Body ground | Ground | Always | Below 1 Ω |
S-GND (L31-20) - Body ground | V - Body ground | Ground | Always | Below 1 Ω |
MPX-B (+B) (L31-21) - Body ground | B - Body ground | Battery | Always | 10 to 14 V |
DOME- (L31-22) - Body ground | L - Body ground | Battery | Always | 10 to 14 V |
MPX+ (L31-25) - Body ground | GR - Body ground | Multiplex communication circuit | - | - |
TACHO (L31-27) - Body ground | L - Body ground | Tachometer signal | Engine running | Pulse generation (See waveform 1) |
BRAKE LEVEL SW (L31-28) - Body ground | Y - Body ground | Brake fluid level signal | Brake fluid level warning light ON | Below 1 V |
Brake fluid level warning light OFF | 10 to 14 V | |||
SPEED (L31-29) - Body ground | V - Body ground | Speed signal (Input) | Engine switch on (IG) and turn the wheel slowly | Pulse generation (See waveform 2) |
ILL (L31-30) - Body ground | G - Body ground | Illumination signal | Engine switch on (IG) | Pulse generation |
P SEAT BELT OUTPUT (L31-31) - Body ground | O - Body ground | Seat belt condition signal (Passenger side) | Passenger seat belt indicator is OFF | Below 1 V |
Passenger seat belt indicator is blinking | 10 to 14 V | |||
FUEL SENDER FR (L31-34) - Body ground | BR - Body ground | Fuel level signal | Engine switch on (IG), fuel level is FULL | Below 1 V |
Engine switch on (IG), fuel level is EMPTY | 4 to 7 V | |||
PH5V (L31-36) - Body ground | B - Body ground | Power source for sunlight sensor | Meter is starting up | 4.7 to 5.2 V |
P-GND (L31-40) - Body ground | W-B - Body ground | Ground (Power ground) | Always | Below 1 Ω |
Waveform 1 (Reference): Using an oscilloscope
Item Condition Symbols
(Terminal No.)TACHO (L31-27) - Body ground Tool Setting 5 V/DIV., 10 msec./DIV Vehicle Condition Engine idle speed Waveform 2 (Reference): Using an oscilloscope
Item Condition Symbols
(Terminal No.)4P (L31-9) - Body ground
SPEED (L31-29) - Body groundTool Setting 5 V/DIV., 20 msec./DIV Vehicle Condition Driving at approx. 20 km/h (12 mph) - HINT:
- As vehicle speed increases, the cycle of the signal waveform narrows.
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Symbols (Terminal No.) | Wiring Color | Terminal Description | Condition | Specified Condition |
TURN-L (f1-1) - Body ground | B - Body ground | Turn signal L | Engine switch on (IG), turn signal LH indicator light OFF | Below 1 V |
Engine switch on (IG), turn signal LH indicator light ON | 10 to 14 V | |||
TURN-R (f1-2) - Body ground | B - Body ground | Turn signal R | Engine switch on (IG), turn signal RH indicator light OFF | Below 1 V |
Engine switch on (IG), turn signal RH indicator light ON | 10 to 14 V | |||
DOME+B-L (f1-3) - Body ground | R- Body ground | Battery R | Always | 10 to 14 V |
SLIP (f1-5) - Body ground | BR - Body ground | Slip signal | Engine switch on (IG), slip indicator is OFF | 10 to 14 V |
Engine switch on (IG), slip indicator is blinking | Below 1 V | |||
SEAT BELT (f1-6) - Body ground | Y - Body ground | Seat belt condition signal (Driver side) | Engine switch on (IG), driver seat belt indicator is OFF | 10 to 14 V |
Engine switch on (IG), driver seat belt indicator is blinking | Below 1 V | |||
AIRBAG (f1-7) - Body ground | O - Body ground | Airbag signal | Engine switch on (IG), airbag indicator is OFF | 10 to 14 V |
Engine switch on (IG), airbag indicator is blinking | Below 1 V | |||
BEAM (f1-8) - Body ground | Y - Body ground | BEAM signal | BEAM switch OFF | 10 to 14 V |
BEAM switch ON | Below 1 V | |||
RR FOG (f1-9) - Body ground | G - Body ground | Rr fog signal | Rr Fog switch OFF | 10 to 14 V |
Rr Fog switch ON | Below 1 V | |||
IG-L (f1-10) - Body ground | L - Body ground | Engine switch signal R | Engine switch off | Below 1 V |
Engine switch on (IG) | 10 to 14 V | |||
IG-R (f1-11) - Body ground | R - Body ground | Engine switch signal L | Engine switch off | Below 1 V |
Engine switch on (IG) | 10 to 14 V | |||
DOME+B-R (f1-12) - Body ground | L - Body ground | Battery L | Always | 10 to 14 V |
FR FOG (f1-14) - Body ground | O - Body ground | Fr fog signal | Fr fog switch OFF | 10 to 14 V |
Fr fog switch ON | Below 1 V | |||
DOOR (f1-15) - Body ground | BR - Body ground | Door courtesy switch signal | Door indicator OFF | 10 to 14 V |
Door indicator ON | Below 1 V | |||
TAIL (f1-16) - Body ground | G - Body ground | Tail signal | Tail signal switch OFF | 10 to 14 V |
Tail signal switch ON | Below 1 V | |||
TURN L-G (f1-17) - Body ground | W- Body ground | Ground | Always | Below 1 Ω |
TURN R-G (f1-18) - Body ground | W- Body ground | Ground | Always | Below 1 Ω |
CHECK SKID CONTROL ECU |

Symbols (Terminal No.) | Wiring Color | Terminal Description | Condition | Specified Condition |
SP1 (A13-7) - Body ground | V-Y - Body ground | Speed signal | Engine switch on (IG), and turn wheel slowly | Pulse generation (See waveform 2) |
Symbols (Terminal No.) | Wiring Color | Terminal Description | Condition | Specified Condition |
SP1 (A48-12) - Body ground | V-Y - Body ground | Speed signal | Engine switch on (IG), and turn wheel slowly | Pulse generation (See waveform 2) |
Waveform 2 (Reference) : Using an oscilloscope
Item Condition Symbols
(Terminal No.)SP1 (A13-7) - Body ground
SP1 (A48-12) - Body groundTool Setting 5 V/DIV., 20 msec./DIV Vehicle Condition Driving at approx. 20 km/h (12 mph)
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CHECK ECM |

Symbols (Terminal No.) | Wiring Color | Terminal Description | Condition | Specified Condition |
TACHO (A7-16) - Body ground | W-L - Body ground | Tachometer signal | Engine is running | Pulse generation (See waveform 1) |
Waveform 1 (Reference): Using an oscilloscope
Item Condition Symbols
(Terminal No.)TACHO (A7-16) - Body ground Tool Setting 5 V/DIV., 20 msec./DIV Vehicle Condition Driving at approx. 20 km/h (12 mph)
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CHECK COMBINATION METER INNER CIRCUIT |


Terminal No. | Wire Harness Side |
L31(1) | GAUGE Fuse |
L31(2) | Turn Signal Flasher (L) |
L31(3) | Turn Signal Flasher (R) |
L31(4) | - |
L31(5) | Gateway ECU |
L31(6) | - |
L31(7) | - |
L31(8) | ECM |
L31(9) | Parts that uses speed signals (Stereo Component Amplifier, ECM) |
L31(10) | - |
L31(11) | Center Airbag Sensor |
L31(12) | - |
L31(13) | - |
L31(14) | - |
L31(15) | Steering Pad Switch |
L31(16) | S/BEAM AMP |
L31(17) | - |
L31(18) | S/BEAM AMP |
L31(19) | Fuel Sender Gage |
L31(20) | Ground (Signal Ground) |
L31(21) | MPX-B Fuse |
L31(22) | DOME Fuse |
L31(23) | - |
L31(24) | - |
L31(25) | Gateway ECU |
L31(26) | - |
L31(27) | ECM |
L31(28) | Brake Fluid Level Warning Switch |
L31(29) | Skid Control ECU |
L31(30) | PANEL Fuse |
L31(31) | Passenger Seat Belt Warning Light |
L31(32) | - |
L31(33) | - |
L31(34) | Fuel Sender Gage |
L31(35) | - |
L31(36) | S/BEAM AMP |
L31(37) | - |
L31(38) | - |
L31(39) | - |
L31(40) | Ground |