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 HARNESS AND CONNECTOR (ABSORBER CONTROL ECU - ECM)
1. Check for open and short circuit in harness and connector between terminal TACH of absorber control and ECM (See ELECTRONIC CIRCUIT INSPECTION PROCEDURE ).
- NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
- OK: GO TO NEXT STEP.
INSPECT ABSORBER CONTROL ECU (TACH OUTPUT)
1. Remove the absorber control ECU with connector still connected.
2. Turn the ignition switch to ON.
3. Connect an oscilloscope to terminals A21 - 11 (TACH) and A22 - 14 (GND) of the absorber control ECU harness side connector.
  
  Fig 1: Connecting Oscilloscope To Terminals TACH & GND
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
4. With the engine idling, and check the signal waveform.
  OK:
  
  Signal wave form as shown in Fig 2 .
  
  Fig 2: Checking Signal Waveform (Engine Idling)
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
HINT: As the engine speed becomes higher, the waveform cycle is getting shorter.
- NG: CHECK AND REPLACE ECM (See ELECTRONIC CIRCUIT INSPECTION PROCEDURE )
- OK: CHECK AND REPLACE ABSORBER CONTROL ECU (See ELECTRONIC CIRCUIT INSPECTION PROCEDURE )