Headlight Relay Circuit

LIGHTING SYSTEM: Headlight Relay Circuit

Headlight Relay Circuit

DESCRIPTION

The multiplex network body ECU controls the HEAD relay when a signal is received from the headlight dimmer switch assembly.

WIRING DIAGRAM









INSPECTION PROCEDURE

PROCEDURE

1. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY
(a) Disconnect the 2C connector from the instrument panel junction block assembly.





(b) Using a service wire, connect 2C-10 of the wire harness side and body ground.
OK:
Headlight comes on.
NG -- INSPECT ENGINE ROOM J/B
OK -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
2. INSPECT ENGINE ROOM J/B
(a) Disconnect the 1H connector from the instrument panel junction block assembly.





(b) Using a service wire, connect 1H-11 of the engine room J/B and body ground.
OK:
Headlight comes on.
NG -- INSPECT ENGINE ROOM J/B
OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR (ENGINE ROOM J/B - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)
3. INSPECT ENGINE ROOM J/B
(a) Measure the voltage according to the value(s) in the table below.





Standard voltage:





NG -- INSPECT ENGINE ROOM J/B
OK -- Continue to next step.
4. INSPECT ENGINE ROOM J/B
(a) Remove the HEAD relay from the engine room J/B.





(b) Using a service wire, connect terminals 5 and 3 of the HEAD relay in the engine room J/B.
OK:
Headlight comes on.
NG -- INSPECT ENGINE ROOM J/B
OK -- REPLACE HEADLIGHT RELAY
5. INSPECT ENGINE ROOM J/B
(a) Measure the voltage according to the value(s) in the table below.





Standard voltage:





NG -- REPLACE ENGINE ROOM J/B
OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR (EACH OF HEADLIGHT CIRCUIT)
6. INSPECT ENGINE ROOM J/B
(a) Remove the HEAD relay from the engine room J/B.





(b) Measure the voltage according to the value(s) in the table below.
Standard voltage:





NG -- CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)
OK -- REPLACE HEADLIGHT RELAY
7. CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)
(a) Disconnect the 1A connector from the engine room junction block assembly.





(b) Measure the voltage according to the value(s) in the table below.
Standard voltage:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE ENGINE ROOM J/B