Inspection Procedure

WARNING: This page is about a different car, the 2004 Lexus ES 330. However, it is still accessible from the selected car via links, so may be relevant.

CHECK COMBINATION METER ASSY (TAU, TAUB, SPD)
1. Disconnect the "C8" connector from combination meter assy.
2. Check voltage (TAUB signal).
  1. Turn the ignition switch to ON.
  2. Measure the voltage between terminal C8-12 of combination meter assy connector and body ground.
  Standard voltage: 10 - 14 V
3. Check voltage (TAU signal).
  1. Turn the ignition switch to ON.
  2. Measure the voltage between terminal C8-21 of combination meter assy connector and body ground.
  Standard voltage: 10 -14 V
4. Check signal waveform (TAU signal).
  1. Connect the oscilloscope to the terminals C8-21 of combination meter assy connector and body ground.
  2. Start engine.
  3. Check the signal waveform.
Fig 4: Signal Waveform (TAU Signal) Conditions Chart
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Result:

Fig 5: Signal Waveform (TAU Signal) Result Chart
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

B: GO TO FUEL SYSTEM

C: CHECK AND REPLACE COMBINATION METER ASSY

A: Go to next step.
INSPECT FUSE (IGN)
1. Check the continuity in IGN fuse.
NG: REPLACE FUSE

OK: REPAIR OR REPLACE HARNESS OR CONNECTOR