Inspection Procedure

CHECK HARNESS AND CONNECTOR (SUSPENSION CONTROL ECU - ECM)
1. Check for open and short circuit in the harness and the connector between the suspension control ECU and ECM (See ELECTRONIC CIRCUIT INSPECTION PROCEDURE ).
1. NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
2. OK: Go To Next Step
INSPECT ECM (TACH OUTPUT)
1. Remove the ECM with connectors being connected.
2. Turn the ignition switch ON.
3. Connect an oscilloscope to terminal E9-5 (TACH) and E11-1 (E1) of the ECM harness side connector.
  
  Fig 1: Connecting Oscilloscope To Terminals E9-5 7 E11-1
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
4. With the engine idling, check the signal waveform.
  - Standard: Signal waveform appears as shown in Fig 2 .
HINT:

As the engine speed becomes higher, the waveform cycle gets shorter.

Fig 2: Checking Signal Waveform Graph (Engine Idling)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. NG: CHECK AND REPLACE ECM (See ELECTRONIC CIRCUIT INSPECTION PROCEDURE )
2. OK: CHECK AND REPLACE SUSPENSION CONTROL ECU (See ELECTRONIC CIRCUIT INSPECTION PROCEDURE )