Headlight Relay Circuit
LIGHTING SYSTEM: Headlight Relay Circuit
Headlight Relay Circuit
DESCRIPTION
The body ECU controls the headlight relays. The headlight relays installed in the power distributor.
System diagram of the power distributor Description and Operation.
System description of the power distributor Description and Operation.
WIRING DIAGRAM
INSPECTION PROCEDURE
PROCEDURE
1. PERFORM ACTIVE TEST BY TECHSTREAM
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the Techstream on.
(d) Enter the following menus: Body Electrical / Body / Active Test.
(e) Check the operation.
Body (Body ECU)
NG -- CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)
OK -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
2. CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)
(a) Disconnect the connector from the J/B No.2 (power distributor).
(b) Measure the voltage according to the value(s) in the table below.
Voltage:
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
3. CHECK MODE MONITOR TERMINAL (H-LP R RELAY, H-LP L RELAY)
(a) Preparation
(1) Connect the connector.
(2) Remove the cover of the fusible link block assembly.
(3) Set the vehicle to the following condition.
- Ignition switch ON.
- Headlight dimmer switch LO.
(b) Check voltage
(1) Measure the voltage between the Mode Monitor Terminal and body ground.
Voltage:
C -- CHECK HARNESS AND CONNECTOR (SHORT CIRCUIT DRIVEN SIDE BY RELAY)
B -- INSPECT JUNCTION BLOCK NO.2 (HEAD LIGHT RELAY)
A -- Continue to next step.
4. CHECK HARNESS AND CONNECTOR (J/B NO. 2 - MODE MONITOR TERMINAL)
(a) Disconnect the connector from the J/B No.2.
(b) Measure the resistance according to the value(s) in the table below.
Resistance:
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
5. INSPECT JUNCTION BLOCK NO.2 (HEAD LIGHT RELAY)
(a) Turn the ignition switch to OFF position.
(b) Remove the J/B No.2.
(c) Inspect the H-LP R.
(1) Connect the positive battery lead to terminal +B of the J/B No.2 and the negative lead to terminal SGND, PGND.
(2) Measure the voltage according to the value(s) in the table below.
Voltage:
(3) Connect the battery negative lead to terminal HRLY of the J/B No.2.
(4) Measure the voltage according to the value(s) in the table below.
Voltage:
(d) Inspect the H-LP L.
(1) Connect the positive battery lead to terminal +B of the J/B No.2 and the negative lead to terminal SGND, PGND.
(2) Measure the voltage according to the value(s) in the table below.
Voltage:
(3) Connect the battery negative lead to terminal HRLY of the J/B No.2.
(4) Measure the voltage according to the value(s) in the table below.
Voltage:
NG -- REPLACE JUNCTION BLOCK NO.2
OK -- Continue to next step.
6. CHECK HARNESS AND CONNECTOR (J/B NO. 2 - INSTRUMENT PANEL J/B)
(a) Disconnect the connectors from the J/B No.2 (power distributor) and instrument panel J/B.
(b) Measure the resistance according to the value(s) in the table below.
Resistance:
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
7. CHECK HARNESS AND CONNECTOR (J/B NO. 2 - HEADLIGHT ASSEMBLY)
(a) Disconnect the connectors from the J/B No.2 (power distributor) and headlight assembly.
(b) Measure the resistance according to the value(s) in the table below.
Resistance:
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
8. CHECK HARNESS AND CONNECTOR (HEADLIGHT ASSEMBLY - BODY GROUND)
(a) Measure the resistance according to the value(s) in the table below.
Resistance:
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
9. CHECK HARNESS AND CONNECTOR (SHORT CIRCUIT DRIVEN SIDE BY RELAY)
(a) Preparation
(1) For easier disconnection remove the J/B No.2 and then take apart the connectors.
(2) Disconnect only the connector "2A".
(b) Check voltage
(1) Measure the voltage between the Mode Monitor Terminal and body ground.
Voltage:
B -- REPLACE JUNCTION BLOCK NO.2
A -- REPAIR OR REPLACE HARNESS OR CONNECTOR (SHORT CIRCUIT BETWEEN HEADLIGHT LO AND J/B NO.2)