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.

DIAGNOSTIC TROUBLE CODE CHECK
1. Check that the DTC P0115/22 does not output.
NG: GO TO ENGINE CONTROL SYSTEM

OK: Go to next step.
INSPECT ECM (THWO)
1. Remove ECM with connector.
2. Turn the ignition switch ON.
3. Measure the waveform according to the value(s) in the figure Fig 2 below.
  Standard
  
  Fig 1: Measuring Waveform
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 2: Identifying Tester Connection Specified Condition Chart
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
HINT:
- The correct waveform is as shown.
- The range shown by A in a figure is condition.
  
  Fig 3: Identifying Graphic Of Correct Waveform
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
NG: CHECK AND REPLACE ECM

OK: Go to next step.
CHECK HARNESS AND CONNECTOR (BETWEEN ECM AND HEATER CONTROL HOUSING SUB-ASSY)
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: CHECK AND REPLACE HEATER CONTROL HOUSING SUB-ASSY