Diesel Data: Automotive Repair

Taillight Relay Circuit








LIGHTING (EXT): LIGHTING SYSTEM: Taillight Relay Circuit

Taillight Relay Circuit

DESCRIPTION

The daytime running light relay receives the light control switch TAIL signal to control the taillight relay.
HINT:
- If only one taillight does not illuminate, check the bulb or wire harness related to the bulb.
- The taillight relay is installed in the instrument panel junction block, so unlike conventional relays, it can not be removed for inspection.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. INSPECT FUSE (TAIL)
(a) Remove the TAIL fuse from the instrument panel junction block.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:






NG -- REPLACE FUSE
OK -- Continue to next step.

2. INSPECT INSTRUMENT PANEL JUNCTION BLOCK




(a) Measure the voltage between the loading slot of the TAIL fuse and body ground.
Standard Voltage:






NG -- CHECK HARNESS AND CONNECTOR (BATTERY - DAYTIME RUNNING LIGHT RELAY)
OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR (FUSE - EACH BULB)
3. CHECK HARNESS AND CONNECTOR (BATTERY - DAYTIME RUNNING LIGHT RELAY)
(a) Disconnect the E42 daytime running light relay connector.




(b) 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. INSPECT DAYTIME RUNNING LIGHT RELAY




(a) Reconnect the E42 daytime running light relay connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:






NG -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
OK -- REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK)