Low Beam Headlight Circuit

LIGHTING (EXT): LIGHTING SYSTEM: Low Beam Headlight Circuit; 2013 MY FR-S [03/2012 -]
- Low Beam Headlight Circuit

DESCRIPTION

The main body ECU (network gateway ECU) receives headlight dimmer switch assembly information signals, and illuminates the low beam headlight.

WIRING DIAGRAM





INSPECTION PROCEDURE

HINT
Inspect the fuses and bulbs for circuits related to this system before performing the following inspection procedure.

PROCEDURE

1. PERFORM ACTIVE TEST USING TECHSTREAM (H-LP RELAY)

(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 / Main Body / Active Test

(e) Check that the relay operates.

Main Body





OK:

Headlight relay operates (low beam headlights illuminate).

Result:





B -- REPLACE MAIN BODY ECU (NETWORK GATEWAY ECU) Removal
A -- Continue to next step.

2. INSPECT H-LP RELAY

(a) Remove the H-LP relay from the engine room relay block.

(b) Inspect the H-LP relay Testing and Inspection.

NG -- REPLACE H-LP RELAY
OK -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (H-LP RELAY - BATTERY)









(a) Measure the voltage according to the value(s) in the table below.

Standard Voltage:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

4. CHECK HARNESS AND CONNECTOR (H-LP RELAY - MAIN BODY ECU (NETWORK GATEWAY ECU))

(a) Disconnect the A73 main body ECU (network gateway ECU) connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance (Check for Open):





Standard Resistance (Check for Short):





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

5. CHECK HARNESS AND CONNECTOR (H-LP RELAY - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

(a) Disconnect the 3C instrument panel junction block assembly connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance (Check for Open):





Standard Resistance (Check for Short):





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

6. CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - MAIN BODY ECU (NETWORK GATEWAY ECU))

(a) Disconnect the 3A and 3C instrument panel junction block assembly connector.

(b) Disconnect the D5 and A73 main body ECU (network gateway ECU) connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance (Check for Open):





Standard Resistance (Check for Short):





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

7. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

(a) Remove the instrument panel junction block assembly Removal.

(b) Remove the main body ECU (network gateway ECU) from the instrument panel junction block assembly.

(c) Measure the resistance according to the value(s) in the table below.









Standard Resistance:





NG -- REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Removal

OK -- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Exterior Lighting System