2003 LEXUS LS430 relay

Fig. 7: Connecting Hand-Held Tester To DLC3
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
3.INSPECT BATTERY VOLTAGE
Standard: 11 to 14 V
If voltage is below 11 V, recharge the battery before proceeding.
1.ACTIVE TEST
HINT:
Performing the hand-held tester's ACTIVE TEST allows relay, VSV, actuator and other items to be
operated without removing any parts. Performing the ACTIVE TEST early in troubleshooting is one way
to save time.
a. Connect the hand-held tester (with CAN VIM) to the DLC3.
b. Turn the ignition switch ON.

c. Perform the ACTIVE TEST by following the directions on the tester screen.
A/C control assy:
A/C CONTROL ASSY - REFERENCE TABLE
CIRCUIT DESCRIPTION
When the defogger switch is turned on, a rear defogger activation request signal is input to the A/C control (A/C
ECU) from the multi-display
1 or center cluster integration panel2 . Then, the A/C control assembly outputs this
signal to the defogger relay (Marking: DEFOG) and the rear window defogger system is activated.
HINT:
1. w/ LEXUS navigation system
2. w/o LEXUS navigation system
WIRING DIAGRAM
ItemTest DetailsDiagnostic Note
DEFOGGER RLY-ROperate rear window defogger OFF/ON-

that the A/C control is turned on and off.
FUSE - REFERENCE TABLE
OK:
When OFF is selected on the hand-held tester, the rear defogger should turn off.
When ON is selected on the hand-held tester, the rear defogger should become active.
NG: Go to step 2
OK: REPLACE AIR CONDITIONER CONTROL ASSY AND IF DEFOGGER STILL DOES
NOT OPERATE, REPLACE MULTI-DISPLAY OR CLUSTER INTEGRATION PANEL
2.INSPECT FUSE (DEFOG, FR IG)
a. Remove the DEFOG H-fuse from the FL block.
b. Remove the FR IG fuse from the engine room R/B.
c. Measure the resistance of the fuse.
Standard: Below 1 ohms
NG: REPLACE FUSE
OK: Go to next step
3.CHECK WIRE HARNESS (DEFOG RELAY - BATTERY)
a. Remove the DEFOG relay from the engine room R/B No. 2.
b. Measure the voltage of the wire harness side connector.
Standard:
DEFOG RELAY - BATTERY - VOLTAGE TABLE
ItemTest DetailsDiagnostic Note
DEFOGGER RLY-ROperate rear window defogger
OFF/ON-
Tester ConnectionConditionSpecified Condition
R/B DEFOG relay terminal 1 -
Body groundIgnition switch ON10 to 14 V
R/B DEFOG relay terminal 5 -
Body groundAlways10 to 14 V

Fig. 9: Checking Wire Harness (Defog Relay - Battery)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS AND CONNECTOR
OK: Go to next step
4.INSPECT RELAY (Marking: DEFOG)
a. Remove the DEFOG relay from the engine room R/B No. 2.
b. Measure the resistance of the relay.
Standard:
RELAY (Marking: DEFOG) - RESISTANCE TABLE
Tester ConnectionSpecified Condition
3-4Below 1 ohms
3-510 kohms or higher
3-5Below 1 ohms (when battery voltage is applied
to terminals 1 and 2)

Fig. 10: Inspecting Relay
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPLACE RELAY
OK: Go to next step
5.CHECK WIRE HARNESS (REAR WINDOW DEFOGGER - DEFOG RELAY AND BODY
GROUND)
a. Disconnect the R22 and R23 defogger connectors.
b. Disconnect the DEFOG relay from the engine room R/B No. 2.
c. Measure the resistance of the wire harness side connectors.
Standard:
REAR WINDOW DEFOGGER - DEFOG RELAY AND BODY GROUND - RESISTANCE
TABLE
Tester ConnectionSpecified Condition
R22-1 - R/B DEFOG relay terminal 3Below 1 ohms
R23-1 - Body groundBelow 1 ohms

Fig. 11: Checking Wire Harness (Rear Window Defogger - Defog Relay And Body Ground)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS AND CONNECTOR

OK: Go to next step
6.CHECK WIRE HARNESS (DEFOG RELAY - A/C CONTROL ASSY)
a. Remove the DEFOG relay from the engine room R/B No. 2.
b. Disconnect the A11 A/C control connector.
c. Measure the resistance of the wire harness side connector.
Standard:
DEFOG RELAY - A/C CONTROL ASSY - RESISTANCE TABLE
Tester ConnectionSpecified Connection
A11-8 (RDFGR) - R/B DEFOG relay terminal 2Below 1 ohms

Fig. 12: Checking Wire Harness (Defog Relay -A/C Control Assy)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS AND CONNECTOR
OK: Go to next step
7.INSPECT REAR WINDOW DEFOGGER (WIRE) (See step 3 in INSPECTION
)
NG: REPLACE REAR WINDOW DEFOGGER
OK: REPLACE AIR CONDITIONER CONTROL ASSY