Check For Intermittent Problems

CHECK FOR INTERMITTENT PROBLEMS
HINT:

A momentary interruption (open circuit) in the connectors and/or wire harness between the sensors and ECUs can be detected in the ECU data list function of the hand held tester.
1. Turn the ignition switch off and connect the hand held tester to the DLC3. (see Fig 1)
2. Turn the ignition switch on (IG). Follow the directions on the hand held tester to display the DATA LIST and select areas where momentary interruption should be monitored.
  HINT:
  
  A momentary interruption (open circuit) cannot be detected for 3 seconds after the ignition switch is turned on (IG) (initial check).
  
  Fig 1: Connecting Hand-Held Tester To DLC3
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 2: Data List Table
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  HINT:
  - If the status remains on (OPN DET displayed), check the continuity between the ECU and the sensors, or between ECUs.
  - The OPN DET display on the hand held tester remains on for 1 second after the harness signal changes from momentary interruption (open circuit) to normal condition.
    
    Fig 3: Identifying Hand-Held Tester Display & Wave Form - OPN DET
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. While observing the screen, gently jiggle the connector or wire harness between the ECU and sensors, or between ECUs.
  Result: OPN DET display does not change.
HINT:

The connector and/or wire harness will be in momentary interruption (open circuit) if the display changes. Repair or replace connector and/or wire harness as one of them is faulty.

Fig 4: Jiggling Connector Or Wire Harness Between ECU & Sensors Or Between ECUs
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002