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 through the ECU data monitor function of the intelligent tester.

1. Turn the ignition switch off and connect the intelligent tester to the DLC3.
2. Turn the ignition switch on. Follow the on-screen directions on the intelligent tester to display the DATA LIST and select areas which should be monitored for momentary interruptions.

   HINT:

   A momentary interruption (open circuit) cannot be detected for 3 seconds after the ignition switch is turned on (initial check).

   Fig 1: Connecting Intelligent Tester To DLC3

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   ITEM DIAGNOSTIC NOTE
   
   

   Item	Measurement Item/Range (Display)	Normal Condition	Diagnostic Note
   SPD SEN FR	FR speed sensor open detection / OPN_DET or NORMAL	OPN_DET: Momentary interruption NORMAL: Normal	-
   SPD SEN FL	FL speed sensor open detection / OPN_DET or NORMAL	OPN_DET: Momentary interruption NORMAL: Normal	-
   SPD SEN RR	RR speed sensor open detection / OPN_DET or NORMAL	OPN_DET: Momentary interruption NORMAL: Normal	-
   SPD SEN RL	RL speed sensor open detection / OPN_DET or NORMAL	OPN_DET: Momentary interruption NORMAL: Normal	-
   EFI COM	EFI communication open detection/OPN DET or NORMAL	OPN_DET: Momentary interruption NORMAL: Normal	-
   YAW RATE SEN	Yaw rate sensor open detection / OPN_DET or NORMAL	OPN_DET: Momentary interruption NORMAL: Normal	-
   DECELE SEN	Deceleration sensor open detection/OPN DET or NORMAL	OPN_DET: Momentary interruption NORMAL: Normal	-
   STEERING SEN	Steering angle sensor open detection/OPN DET or NORMAL	OPN_DET: Momentary interruption NORMAL: Normal	-
   ACC SEN	Accumulator pressure sensor open detection / OPN DET or NORMAL	OPN_DET: Momentary interruption NORMAL: Normal	-

   HINT:

   • If the intelligent tester status remains open, check the continuity between the ECU and the sensors, or between ECUs.
   • The OPEN display on the intelligent tester remains on for 1 second after the harness signal changes from momentary interruption (open circuit) to normal condition.
     Fig 2: Identifying Blinking Pattern

     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.

   OK: OPEN-screen display does not change.