Inspection Procedure

1. Connect the oscilloscope to terminals 1 (GND) and 7 (TAU) of the clock assy connector.
Fig 1: Identifying Clock Assy Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
2. Start the engine.
3. Check the signal wave form (TAU signal).
   CLOCK ASSY - REFERENCE TABLE
   
   

   Item	Condition
   Tool setting	10 V/DIV, 100 ms/DV
   Vehicle condition	Engine idle speed

   Fig 2: Identifying Signal Wave Form Graph

   Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
4. Turn the ignition switch to ON.
5. Measure the voltage between terminal 20 (IG) of the clock assy and body ground.
   Fig 3: Identifying Clock Assy Connector Terminal IG

   Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

   Standard: 10 to 14 V 

   Result: 

A: GO TO FUEL SYSTEM (See  HOW TO PROCEED WITH TROUBLESHOOTING  (2AZ-FE),  HOW TO PROCEED WITH TROUBLESHOOTING  (2AZ-FE(PZEV)),  HOW TO PROCEED WITH TROUBLESHOOTING  (1MZ-FE/3MZ-FE)) 

B: Go to step 2 

C: REPLACE CLOCK ASSY (See step 4 on  REPLACEMENT  ) 

1. Check that continuity exists in the GAUGE1 fuse.

   NG: REPLACE FUSE 

   OK: REPAIR OR REPLACE HARNESS OR CONNECTOR