LIGHT SENSOR
Note. Adjust light sensor if headlights come on too early or too late.
If headlights come on too early, turn ring on light sensor counterclockwise. (Scheme 1)or (Scheme 2). If headlights come on too late, turn ring clockwise.
Scheme 1
Scheme 2
COMPONENT TESTS
Note. For headlight switch and relay testing, see STEERING COLUMN SWITCHES article.
AUTOMATIC LIGHT SENSOR
Perform CIRCUIT TESTS first. If results are as specified, replace automatic light sensor.
BODY CONTROL ECU (LS400)
Refer to appropriate MULTIPLEX CONTROL SYSTEMS article.
DRIVER'S DOOR ECU (LS400)
Refer to appropriate MULTIPLEX CONTROL SYSTEMS article.
LIGHT CONTROL ECU (GS300 & GS400)
Testing information not available from manufacturer.
INTEGRATION RELAY
Note. Integration relay is not used on GS300, GS400 and LS400.
ES300
Remove integration relay. See COMPONENT LOCATIONS. Using a jumper wire, connect positive battery positive to integration relay terminal No. 1 and connect battery negative alternately to terminals No. 5, 6 and 10. (Scheme 18)and (Scheme 19). Buzzer in integration relay should sound when each terminals are connected/probed, and turn off when jumper wire is removed. Replace relay as necessary. If relay is okay, perform circuit test. See CIRCUIT TESTS.
SC300 & SC400
Remove integration relay. See COMPONENT LOCATIONS . Perform integration relay circuit test. See CIRCUIT TESTS .
CIRCUIT TESTS
Note. For electrical component locations, see COMPONENT LOCATIONS .
All Models
- Turn ignition off. Disconnect light sensor harness connector. Perform light sensor circuit test with harness connector disconnected. (Scheme 3)- (Scheme 9). If results are as specified, go to next step.
- Turn ignition on, light control switch to AUTO position, and ensure vehicle surroundings are bright. Reconnect light sensor harness connector. Perform light sensor circuit voltage test by backprobing sensor harness connector. (Scheme 10)- (Scheme 17). If results are not as specified, check and repair affected circuit. See «WIRING DIAGRAMS»(ref-96822-S36444064402001041900000). If results are as specified, replace automatic light sensor.
Scheme 3
Scheme 4
Scheme 5
Scheme 6
Scheme 7
Scheme 8
Scheme 9
Scheme 10
Scheme 11
Scheme 12
Scheme 13
Scheme 14
Scheme 15
Scheme 16
Scheme 17
INTEGRATION RELAY CIRCUIT
Note. Canadian models equipped with Daytime Running Lights (DRL) use a different integration relay. See DAYTIME RUNNING LIGHTS article.
ES300, SC300 & SC400
Remove integration relay. See COMPONENT LOCATIONS. Inspect integration relay connector on fuse/relay block and integration relay harness connectors. (Scheme 18)- (Scheme 23). If connector tests are okay, check related circuits. See WIRING DIAGRAMS.
