Inspection Procedure

WARNING: This page is about a different car, the 2004 Lexus LS 430. However, it is still accessible from the selected car via links, so may be relevant.

PERFORM ACTIVE TEST USING HAND-HELD TESTER
1. Select the ACTIVE TEST, use the hand-held tester to generate a control command, and then check that the A/C control assembly is turned on and off.
  A/C control assembly:
  
  Fig 1: A/C Control Assembly - Active Test Chart
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
OK: Go to next step.

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 A/C CONTROL ASSEMBLY AND IF DEFOGGER STILL DOES NOT OPERATE, REPLACE MULTI-DISPLAY OR CLUSTER INTEGRATION PANEL
CHECK FUSE (DEFOG, FR IG)
1. Remove the DEFOG H-fuse from the FL block.
2. Remove the FR IG fuse from the engine room R/B.
Standard: 1 Ω

NG: REPLACE FUSE

OK: Go to next step.
CHECK WIRE HARNESS (ENGINE ROOM R/B NO. 2 - BODY GROUND)
1. Remove the DEFOG relay from the engine room R/B No. 2.
2. Measure the voltage between the engine room R/B No. 2 and body ground.
  Standard:
  
  Fig 2: Terminals Voltage Reference Chart
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 3: Checking Wire Harness (Engine Room R/B No 2 - Body Ground)
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
NG: REPAIR OR REPLACE WIRE HARNESS AND CONNECTOR

OK: Go to next step.
INSPECT RELAY (DEFOG)
1. Remove the DEFOG relay from the engine room R/B No 2.
2. Measure the resistance.
  Standard:
  
  Fig 4: Terminals Resistance Reference Chart
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 5: Inspecting Relay (DEFOG)
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
NG: REPLACE RELAY

OK: Go to next step.
CHECK WIRE HARNESS (REAR WINDOW DEFOGGER - ENGINE ROOM R/B NO. 2 AND BODY GROUND)
1. Disconnect the R22 and R23 defogger connectors.
2. Disconnect the DEFOG relay from the engine room R/B No. 2.
3. Measure the resistance of the wire harness side connectors.
  Standard:
  
  Fig 6: Terminals Resistance Reference Chart
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 7: Checking Wire Harness (Rear Window Defogger - Engine Room R/B No 2 And Body Ground)
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
NG: REPAIR OR REPLACE WIRE HARNESS AND CONNECTOR

OK: Go to next step.
CHECK WIRE HARNESS (ENGINE ROOM R/B NO. 2 - A/C CONTROL ASSEMBLY )
1. Remove the DEFOG relay from engine room R/B No. 2.
2. Disconnect the A11 A/C control assembly connector.
3. Measure the resistance of the wire harness side connector.
  Standard:
  
  Fig 8: Terminals Resistance Reference Chart
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 9: Checking Wire Harness (Engine Room R/B No 2 - A/C Control Assembly)
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
NG: REPAIR OR REPLACE HARNESS AND CONNECTOR

OK: Go to next step.
INSPECT REAR WINDOW DEFOGGER (WIRE) (See INSPECTION )
NG: REPAIR OR REPLACE REAR WINDOW DEFOGGER

OK: REPLACE A/C CONTROL ASSEMBLY