LEMON Manuals: Even more car manuals for everyone
Home >> Lexus >> 2003 >> RX 300 AWD >> Repair and Diagnosis >> General Information >> OEM General Information >> Troubleshooting >> Problem Symptoms Table >> Headlight And Taillight System:

Headlight And Taillight System:

This system uses the multiplex communication system, so check diagnosis system of the multiplex communication system before you proceed with troubleshooting.

HINT:

To inspect the bulb and light control ECU, replace them with the ones working normally and judge whether they work normally or not.

HEADLIGHT AND TAILLIGHT SYSTEM TROUBLE SYMPTOMS REFERENCE

Symptom Suspect Area See Section
Only one headlight comes on.
  1. Daytime Running Light No. 2, 3, 4 Relay
  2. Daytime Running Light Main Relay
  3. Bulb
  4. (1) Headlight (Light Control ECU)
  5. Wire Harness
  1. INSPECTION
  2. INSPECTION
  3. -
  4. -
  5. -
"LO-Beam" does not light (All).
  1. Headlight Control Relay
  2. (1) Headlight (Light Control ECU)
  3. Wire Harness
  1. INSPECTION
  2. -
  3. -
"LO-Beam" does not light (One side).
  1. Bulb
  2. HEAD LH(LWR) Fuse
  3. HEAD RH(LWR) Fuse
  4. (1) Headlight (Light Control ECU)
  5. Wire Harness
  1. -
  2. ENGINE ROOM JUNCTION BLOCK
  3. ENGINE ROOM JUNCTION BLOCK
  4. -
  5. -
"Hl-Beam" does not light (All).
  1. Headlight Dimmer Switch
  2. Daytime Running Light Main Relay
  3. Wire Harness
INSPECTION
INSPECTION
-
"Hl-Beam" does not light (One side).
  1. Bulb
  2. HEAD LH(UPR) Fuse
  3. HEAD RH(UPR) Fuse
  4. Daytime Running Light No. 3 Relay
  5. Wire Harness
  1. ENGINE ROOM JUNCTION BLOCK
  2. -
  3. ENGINE ROOM JUNCTION BLOCK
  4. INSPECTION
-
"Flash" does not light.
  1. Headlight Dimmer Switch
  2. Daytime Running Light Main Relay
  3. Wire Harness
INSPECTION
INSPECTION
-
Headlight does not come on.
  1. Headlight Control Relay
  2. Daytime Running Light Main Relay
  3. Daytime Running Light No. 2, 3, 4 Relay
  4. Headlight Dimmer Switch
  5. Light Control Switch
  6. Wire Harness
  7. (1) Headlight (Light Control ECU)
  8. Bulb
  1. INSPECTION
  2. INSPECTION
  3. INSPECTION
  4. INSPECTION
  5. INSPECTION g
  6. -
  7. -
  8. -
Headlight does not come on with light control switch in HEAD.
  1. Light Control Switch
  2. (1) Headlight (Light Control ECU)
  3. Wire Harness
  1. INSPECTION
  2. -
  3. -
Headlight does not go out with light control switch in OFF.
  1. Headlight Control Relay
  2. (1) Headlight (Light Control ECU)
  3. Wire Harness
  1. INSPECTION
  2. -
  3. -
Headlight flickers.
  1. Bulb
  2. (1) Headlight (Light Control ECU)
  3. Wire Harness
  4. INSPECTION
  1. -
  2. INSPECTION
  3. -
Headlight is dark.
  1. Bulb
  2. (1) Headlight (Light Control ECU)
  3. Wire Harness
  1. -
  2. -
  3. -
Taillight does not come on with light control switch in TAIL.
  1. Taillight Control Relay (Instrument Panel J/B)
  2. Light Control Switch
  3. Wire Harness
  1. INSPECTION
  2. -
  3. -
Taillight does not go out with light control switch in OFF.
  1. Taillight Control Relay
  2. Light Control Switch
  3. Wire Harness
  1. INSPECTION
  2. INSPECTION
  3. -
Headlight does not come on with engine running and light control switch in OFF.
  1. ECU-B Fuse
  2. GAUGE Fuse
  3. Daytime Running Light Main Relay
  4. Daytime Running Light No. 2, 3, 4 Relay
  5. Generator L Terminal
  6. Parking Brake Switch
  7. Wire Harness
  1. ENGINE ROOM JUNCTION BLOCK
  2. ENGINE ROOM JUNCTION BLOCK
  3. INSPECTION
  4. INSPECTION
  5. CHARGING SYSTEM
  6. COMBINATION METER ECU POWER SOURCE CIRCUIT
  7. -
(1) : HID Type