ES300
| Component | Location |
|---|---|
| Automatic Light Control Sensor | On Top Left Side Of Instrument Panel |
| Headlight Fuses | In Fuse/Relay Block, Near Left Front Shock Tower |
| Headlight Relay | In Fuse/Relay Block, Near Left Front Shock Tower |
| Integration Relay | In Fuse/Relay Block, Behind Left Side Of Instrument Panel |
| Taillight Relay | In Fuse/Relay Block, Behind Left Side Of Instrument Panel |
COMPONENT LOCATIONS (ES300)
GS300 & GS430
| Component | Location |
|---|---|
| Automatic Light Control Sensor | On Top Left Side Of Instrument Panel |
| Body Control ECU No. 2 | Behind Driver-Side Kick Panel |
| Driver's Door ECU | Behind Driver's Door Panel |
| Headlight Fuses | In Underhood Junction Blocks No. 1 & 2 |
| Headlight Relay | In Underhood Junction Block No. 1 |
| Left & Right-Side Light Control ECU | Behind Left & Right-Side Headlights |
| Taillight Relay | In Fuse/Relay Block, Near Driver-Side Kick Panel |
COMPONENT LOCATIONS (GS300 & GS430)
IS300
| Component | Location |
|---|---|
| Automatic Light Control Sensor | On Top Left Side Of Instrument Panel |
| Body Control ECU No. 2 | Behind Driver-Side Kick Panel |
| Headlight Fuses | In Underhood Junction Blocks No. 1 & 2 |
| Headlight Relay | In Underhood Junction Block No. 1 |
| Taillight Relay | In Driver-Side Junction Block, Behind Driver-Side Kick Panel |
COMPONENT LOCATIONS (IS300)
LS430
| Component | Location |
|---|---|
| Automatic Light Control Sensor | On Top Center Of Instrument Panel |
| Driver's Side Junction Block | Behind Driver's Door Panel |
| Front Light ECU | On Left Side Of Engine Compartment |
| Headlight & Taillight Fuses | In Fuse/Relay Block, Near Left Front Shock Tower |
| Headlight Relay | In Fuse/Relay Block, Near Left Front Shock Tower |
COMPONENT LOCATIONS (LS430)
LX470
| Component | Location |
|---|---|
| Automatic Light Control Sensor | On Top Right Side Of Instrument Panel |
| Body Control ECU | Behind Center Of Instrument Panel, Above Radio |
| Headlight Fuses | In Fuse/Relay Block, Near Left Front Shock Tower |
| Headlight Relay | In Fuse/Relay Block, Near Left Front Shock Tower |
| Taillight Relay | In Fuse/Relay Block, Near Driver-Side Kick Panel |
COMPONENT LOCATIONS (LX470)
RX300
| Component | Location |
|---|---|
| Automatic Light Control Sensor | On Top Left Side Of Instrument Panel |
| Headlight Fuses | In Fuse/Relay Block, Near Left Front Shock Tower |
| Headlight Relay | In Fuse/Relay Block, Near Left Front Shock Tower |
| Taillight Relay | In Fuse/Relay Block, Behind Left Side Of Instrument Panel |
COMPONENT LOCATIONS (RX300)
AUTOMATIC LIGHT CONTROL SENSOR
Note. Adjust automatic light control sensor if headlights illuminate too early or too late. Adjustment information for GS300, GS430 and RX300 models is not available from manufacturer.
Note. Adjustment on LS430 requires Lexus hand-held tester and appropriate software. Follow tester manufacturer's instructions.
ES300 & IS300
If headlights illuminate too early, turn sensitivity knob on sensor counterclockwise. (Scheme 1) If headlights illuminate too late, turn adjuster clockwise.
If headlights illuminate too early, turn sensitivity knob on sensor clockwise. (Scheme 1) If headlights illuminate too late, turn adjuster counterclockwise.
Scheme 1
CIRCUIT TESTS
Note. For headlight system circuit tests not included, see appropriate wiring diagram in HEADLIGHT SYSTEMS or DAYTIME RUNNING LIGHTS articles.
AUTOMATIC LIGHT CONTROL SENSOR CIRCUIT
- Turn ignition off. Disconnect automatic light control sensor harness connector. Check circuit values at appropriate terminals of automatic light control sensor harness connector. (Scheme 2) Ensure circuit values are as specified. See appropriate SENSOR CIRCUIT VALUES table. If circuit values are as specified, go to next step. If circuit values are not as specified, check and repair affected circuit. See appropriate wiring diagram in HEADLIGHT SYSTEMS article.
- Reconnect automatic light control sensor harness connector. Turn ignition on. Turn light control switch to AUTO position, and ensure vehicle surroundings are bright. Check circuit values by backprobing at appropriate terminals of automatic light control sensor harness connector. (Scheme 2)- (Scheme 7). Ensure circuit values are as specified. See appropriate SENSOR CIRCUIT VALUES table. If circuit values are as specified, replace automatic light control sensor. If circuit values are not as specified, check and repair affected circuit. See appropriate wiring diagram in HEADLIGHT SYSTEMS article.
Automatic Light Control Sensor Circuit Values (ES300)
| Tester Connection | Condition | Circuit Value |
|---|---|---|
| 4 & Ground | Ignition Switch In LOCK Or ACC Position | No Voltage |
| 4 & Ground | Ignition Switch in ON Position | 5.2-9.0 Volts |
| 5 & Ground | Ignition Switch In LOCK Or ACC Position | No Voltage |
| 5 & Ground | Ignition Switch in ON Position | Battery Voltage |
| 6 & Ground | Constant | Continuity |
| 6 & Ground | Light Control Switch In AUTO Position | Continuity |
SENSOR CIRCUIT VALUES - HARNESS DISCONNECTED (ES300)
| Tester Connection | Condition | Circuit Value |
|---|---|---|
| 5 & Ground | Ignition Switch In LOCK Or ACC Position | No Voltage |
| 5 & Ground | Ignition Switch In ON Position | 9.5 Volts Or Greater |
| 6 & Ground | Constant | Continuity |
SENSOR CIRCUIT VALUES - HARNESS CONNECTED (ES300)
Automatic Light Control Sensor Circuit Values (GS300, GS430 & IS300)
| Tester Connection | Condition | Circuit Value |
|---|---|---|
| 1 & Ground | Ignition Switch In LOCK Or ACC Position | No Voltage |
| 1 & Ground | Ignition Switch In ON Position | Battery Voltage |
| 3 & Ground | Constant | Continuity |
| 4 & Ground | Ignition Switch In LOCK Or ACC Position | No Voltage |
| 4 & Ground | Ignition Switch In ON Position | 5.2-9.0 Volts |
SENSOR CIRCUIT VALUES - HARNESS DISCONNECTED (GS300, GS430 & IS300)
| Tester Connection | Condition | Circuit Value |
|---|---|---|
| 1 & Ground | Ignition Switch In LOCK Or ACC Position | No Voltage |
| 1 & Ground | Ignition Switch In ON Position | 9.5 Volts Or Greater |
| 3 & Ground | Constant | Continuity |
SENSOR CIRCUIT VALUES - HARNESS CONNECTED (GS300, GS430 & IS300)
Automatic Light Control Sensor Circuit Values (LS430)
| Tester Connection | Condition | Circuit Value |
|---|---|---|
| 3 & Ground | Close Driver's Door With Ignition Switch In OFF Position | No Voltage |
| 3 & Ground | Ignition Switch in ON Position | Battery Voltage |
| 5 & Ground | Constant | Continuity |
| 6 & Ground | Ignition Switch In ON Position | 5.2-9.0 Volts |
| 6 & Ground | Close Driver's Door With Ignition Switch In OFF Position | No Voltage |
SENSOR CIRCUIT VALUES - HARNESS DISCONNECTED (LS430)
| Tester Connection | Condition | Circuit Value |
|---|---|---|
| 5 & Ground | Ignition Switch In ON Position | Battery Voltage |
| 6 & Ground | Constant | Pulse Generation |
SENSOR CIRCUIT VALUES - HARNESS CONNECTED (LS430)
Automatic Light Control Sensor Circuit Values (LX470)
| Tester Connection | Condition | Circuit Value |
|---|---|---|
| 1 & Ground | Ignition Switch In ON Position | Battery Voltage |
| 1 & Ground | Ignition Switch In LOCK Or ACC Position | No Voltage |
| 2 & Ground | Constant | Battery Voltage |
| 3 & Ground | Driver's Door Courtesy Switch In OFF Position | No Continuity |
| 3 & Ground | Driver's Door Courtesy Switch In ON Position | Continuity |
| 5 & Ground | Light Control Switch In HEAD Position | Continuity |
| 6 & Ground | Light Control Switch In AUTO Position | Continuity |
| 7 & Ground | Light Control Switch In TAIL Position | Continuity |
SENSOR CIRCUIT VALUES - HARNESS DISCONNECTED (LX470)
| Tester Connection | Condition | Circuit Value |
|---|---|---|
| 1 & Ground | Ignition Switch In ON Position | 10 Volts Or Greater |
| 1 & Ground | Ignition Switch In OFF Position | One Volt Or Less |
| 3 & Ground | Driver's Door Courtesy Switch in OFF Position | 9 Volts Or Greater |
| 3 & Ground | Driver's Door Courtesy Switch in ON Position | One Volt Or Less |
| 5 & Ground | Light Control Switch In FLASH Position | 0.3 Volt Or Less |
| 5 & Ground | Vehicle In Direct Sun Light | 1.8 Volts Or Less |
| 7 & Ground | Vehicle In Direct Sun Light | 1.5 Volts Or Less |
SENSOR CIRCUIT VALUES - HARNESS CONNECTED (LX470)
Automatic Light Control Sensor Circuit Values (RX300)
| Tester Connection | Condition | Circuit Value |
|---|---|---|
| 3 & Ground | Constant | Continuity |
| 1 & Ground | Ignition Switch In LOCK Or ACC | No Voltage |
| 1 & Ground | Ignition Switch On | 9.5 Volts Or Greater |
SENSOR CIRCUIT VALUES - HARNESS CONNECTED (RX300)
Scheme 2
Scheme 3
Scheme 4
Scheme 5
Scheme 6
Scheme 7
COMBINATION SWITCH CIRCUIT
With combination switch connected, check circuit values by backprobing appropriate connector terminal on back side of harness connector. (Scheme 8) Ensure circuit values are as specified. See appropriate COMBINATION SWITCH CIRCUIT VALUES table. If circuit values are not as specified, repair as necessary. See appropriate wiring diagram in HEADLIGHT SYSTEMS article.
COMBINATION SWITCH CIRCUIT VALUES (ES300 & RX300)
| Tester Connection | Condition | Circuit Value |
|---|---|---|
| 7 & Ground | Dimmer Switch In LOW BEAM Position | No Voltage |
| 7 & Ground | Dimmer Switch In HIGH BEAM Or FLASH Position | Battery Voltage |
| 8 & Ground | Dimmer Switch In LOW BEAM Or HIGH BEAM Position | No Voltage |
| 8 & Ground | Dimmer Switch In FLASH Position | Battery Voltage |
| 12 & Ground | Light Control Switch In OFF, TAIL Or HEAD Position | No Voltage |
| 12 & Ground | Light Control Switch In AUTO Position | Battery Voltage |
| 13 & Ground | Light Control Switch In OFF Or TAIL Position | No Voltage |
| 13 & Ground | Light Control Switch In HEAD Position | Battery Voltage |
| 14 & Ground | Light Control Switch In OFF Position | No Voltage |
| 14 & Ground | Light Control Switch In TAIL Or HEAD Position | Battery Voltage |
| 16 & Ground | Constant | Continuity |
| 17 & Ground | Dimmer Switch In HIGH BEAM Or FLASH Position | No Voltage |
| 17 & Ground | Dimmer Switch In LOW BEAM Position | Battery Voltage |
COMBINATION SWITCH CIRCUIT VALUES (ES300 & RX300)
Combination Switch Circuit Values (GS300 & GS430)
| Tester Connection | Condition | Circuit Value |
|---|---|---|
| 13 & Ground | Light Control Switch In OFF, TAIL Or HEAD Position | No Voltage |
| 13 & Ground | Light Control Switch In AUTO Position | Battery Voltage |
| 14 & Ground | Light Control Switch In OFF Or TAIL Position | No Voltage |
| 14 & Ground | Light Control Switch In HEAD Position | Battery Voltage |
| 15 & Ground | Light Control Switch In OFF Position | No Voltage |
| 15 & Ground | Light Control Switch In TAIL Or HEAD Position | Battery Voltage |
COMBINATION SWITCH CIRCUIT VALUES (GS300 & GS430)
Combination Switch Circuit Values (IS300)
| Tester Connection | Condition | Circuit Value |
|---|---|---|
| 12 & Ground | Switch In OFF, TAIL Or HEAD | Battery Voltage |
| 12 & Ground | Switch In AUTO Position | No Voltage |
| 13 & Ground | Switch In OFF Or TAIL Position | Battery Voltage |
| 13 & Ground | Switch In HEAD Position | No Voltage |
| 14 & Ground | Light Control Switch In OFF Position | Battery Voltage |
| 14 & Ground | Light Control Switch In TAIL Or HEAD Position | No Voltage |
COMBINATION SWITCH CIRCUIT VALUES (IS300)
Combination Switch Circuit Values (LS430)
| Tester Connection (1) | Condition | Circuit Value | |
|---|---|---|---|
| C14-1 To C14-8 | Constant | Battery Voltage | |
| C14-2 & C14-8 | |||
| Ignition Switch In OFF Or ACC Position | No Voltage | ||
| Ignition Switch On | Battery Voltage | ||
| C14-8 & Ground | Constant | No Voltage | |
| (1) Measure at ECM connector C14 located behind driver-side kick panel. (Scheme 10) | |||
| (1) | Measure at ECM connector C14 located behind driver-side kick panel. (Scheme 10) |
COMBINATION SWITCH CIRCUIT VALUES (LS430)
Combination Switch Circuit Values (LX470)
| Tester Connection | Condition | Circuit Value |
|---|---|---|
| 13 & Ground | Light Control Switch In OFF Or TAIL Position | Battery Voltage |
| 13 & Ground | Light Control Switch In HEAD Position | No Voltage |
| 14 & Ground | Light Control Switch In OFF Position | Battery Voltage |
| 14 & Ground | Light Control Switch In TAIL Or HEAD Position | No Voltage |
| 16 & Ground | Constant | Continuity |
COMBINATION SWITCH CIRCUIT VALUES (LX470)
Scheme 8
Scheme 9
Scheme 10
INTEGRATION RELAY CIRCUIT
Note. GS300, GS430, IS300, LS430, LX470 and RX300 are not equipped with an integration relay.
Remove integration relay. See COMPONENT LOCATIONS. Check circuit values at appropriate connector terminals of integration relay. (Scheme 11)and (Scheme 12). Ensure circuit values are as specified. See appropriate INTEGRATION RELAY CIRCUIT VALUES table. If circuit values are as specified, replace integration relay. If circuit values are not as specified, repair circuit as necessary. See appropriate wiring diagram in HEADLIGHT SYSTEMS article.
| Tester Connection | Condition | Circuit Value |
|---|---|---|
| 1 & Ground | Constant | Battery Voltage |
| 2 & Ground | Constant | Battery Voltage |
| 4 & Ground | All Doors Closed (Except Driver's Door) | No Continuity |
| 4 & Ground | One Door Open (Except Driver's Door) | Continuity |
| 5 & Ground | Key Unlock Warning Switch In OFF Position | No Continuity |
| 5 & Ground | Key Unlock Warning Switch In ON Position | Continuity |
| 6 & Ground | Driver's Door Closed | No Continuity |
| 6 & Ground | Driver's Door Open | Continuity |
| 7 & Ground | Ignition Switch In LOCK Or ACC Position | No Voltage |
| 7 & Ground | Ignition Switch In ON Position | Battery Voltage |
| 8 & Ground | Seat Belt Unfastened | No Continuity |
| 8 & Ground | Seat Belt Fastened | Continuity |
| 9 & Ground | Ignition Switch In LOCK Or ACC Position | No Voltage |
| 9 & Ground | Ignition Switch In ON Position | Battery Voltage |
| 10 & Ground | Constant | Continuity |
| 11 & Ground | Ignition Switch In LOCK Position | No Voltage |
| 11 & Ground | Ignition Switch In ACC or ON Position | Battery Voltage |
INTEGRATION RELAY CIRCUIT VALUES (ES300 - JUNCTION BLOCK SIDE)
| Tester Connection | Condition | Circuit Value |
|---|---|---|
| A1 & Ground | Constant | Battery Voltage |
| A3 & Ground | Constant | Continuity |
| A5 & Ground | Driver's Door Closed | No Continuity |
| A5 & Ground | Driver's Door Open | Continuity |
| A6 & Ground | Passenger's Door Closed | No Continuity |
| A6 & Ground | Passenger's Door Open | Continuity |
| A7 & Ground | Passenger's Door Closed | No Continuity |
| A7 & Ground | Passenger's Door Open | Continuity |
| A8 & Ground | Engine Running | Battery Voltage |
| A9 & Ground | Rear Door Closed | No Continuity |
| A9 & Ground | Rear Door Open | Continuity |
| A11 & A12 | Constant | Continuity |
| A12 & A25 | Constant | Continuity |
| A13 & Ground | Light Control Switch in AUTO Position | No Continuity |
| A13 & Ground | Light Control Switch In OFF, TAIL Or HEAD Position | Continuity |
| A14 & Ground | Light Control Switch In OFF Position | No Continuity |
| A14 & Ground | Light Control Switch In HI Or FLASH Position | Continuity |
| A15 & Ground | Trunk Compartment Closed | No Continuity |
| A15 & Ground | Trunk Compartment Open | Continuity |
| A16 & Ground | Door Lock Manual Switch In OFF Or UNLOCK Position | No Continuity |
| A16 & Ground | Door Lock Manual Switch In LOCK Position | Continuity |
| A17 & Ground | Door Lock Manual Switch In OFF Or LOCK Position | No Continuity |
| A17 & Ground | Door Lock Manual Switch In UNLOCK Position | Continuity |
| A18 & Ground | Driver's & Passenger's Door Key Lock/Unlock Switch In OFF Or UNLOCK Position | No Continuity |
| A18 & Ground | Driver's & Passenger's Door Key Lock/Unlock Switch In LOCK Position | Continuity |
| A19 & Ground | Driver's Door Key Lock/Unlock Switch In OFF Or LOCK Position | No Continuity |
| A19 & Ground | Driver's Door Key Lock/Unlock Switch In UNLOCK Position | Continuity |
| A20 & Ground | Passenger's Door Key Lock/Unlock Switch In OFF Or LOCK Position | No Continuity |
| A20 & Ground | Passenger's Door Key Lock/Unlock Switch In UNLOCK Position | Continuity |
| A22 & Ground | Parking Brake Switch In OFF Position | No Continuity |
| A22 & Ground | Parking Brake Switch In ON Position | Continuity |
| A24 & Ground | Brake Fluid Level Float Up | No Continuity |
| A24 & Ground | Brake Fluid Level Float Down | Continuity |
| B2 & Ground | Light Control Switch In OFF Position | No Continuity |
| B2 & Ground | Light Control Switch In TAIL Or HEAD Position | Continuity |
| B5 & Ground | Light Control Switch In OFF Or TAIL Position | Continuity |
| B5 & Ground | Light Control Switch In HEAD Position | Continuity |
INTEGRATION RELAY CIRCUIT VALUES (ES300 - HARNESS SIDE)
Scheme 11
Scheme 12
COMPONENT TESTS
Note. For light control switch and relay testing, see COMPONENT TESTS in STEERING COLUMN SWITCHES article.
Note. See AUTOMATIC LIGHT CONTROL SENSOR CIRCUIT under CIRCUIT TESTS.
BODY CONTROL ECU (GS300, GS430 & LS430)
Note. See appropriate BODY CONTROL SYSTEMS article.
DRIVER'S DOOR ECU (GS300, GS430 & LS430)
Note. See appropriate MULTIPLEX CONTROL SYSTEMS article.
LIGHT CONTROL ECU (GS300 & GS430)
Note. Information is not available from manufacturer.
COMBINATION SWITCH
Note. See REMOVAL & INSTALLATION in STEERING COLUMN SWITCHES article.