Vehicle Stability Control System (For Sedan) Check For Intermittent Problems

Brake. Yaris. Ncp93, 131
Brake Control Dynamic Control Systems. Yaris. Ncp93, 131

  1. CHECK FOR INTERMITTENT PROBLEMS

Vehicle Stability Control System (For Sedan) -- Check For Intermittent Problems



CHECK FOR INTERMITTENT PROBLEMS
HINT:
A momentary interruption (open circuit) in the connectors and/or wire harnesses between the sensors and ECUs can be detected using the ECU Data List function of the Techstream.

  1. Turn the ignition switch off.

  2. Connect the Techstream to the DLC3.

  3. Turn the ignition switch to ON.

  4. Turn the Techstream on.

  5. Follow the directions on the Techstream to display the Data List and select areas where momentary interruptions should be monitored.

    HINT:
    1. A momentary interruption (open circuit) cannot be detected for 3 seconds after the ignition switch is turned to ON (initial check).
    2. If the ERROR display remains displayed, measure the resistance between the ECUs and sensors, or between ECUs.
    3. The ERROR display on the Techstream will remain displayed for 1 second after the harness signal changes from momentary interruption (open circuit) to the normal condition.

    ABS/VSC/TRAC
    Tester Display
    		Measurement Item/Range
    		Normal Condition
    		Diagnostic Note
    FR Speed Open
    		FR speed sensor open detection/ERROR or NORMAL
    		ERROR: Momentary interruption
    NORMAL: Normal
    		-
    FL Speed Open
    		FL speed sensor open detection/ERROR or NORMAL
    		ERROR: Momentary interruption
    NORMAL: Normal
    		-
    RR Speed Open
    		RR speed sensor open detection/ERROR or NORMAL
    		ERROR: Momentary interruption
    NORMAL: Normal
    		-
    RL Speed Open
    		RL speed sensor open detection/ERROR or NORMAL
    		ERROR: Momentary interruption
    NORMAL: Normal
    		-
    EFI Communication Open
    		EFI communication open detection/ERROR or NORMAL
    		ERROR: Momentary interruption
    NORMAL: Normal
    		-
    Yaw Rate Open
    		Yaw rate sensor open detection/ERROR or NORMAL
    		ERROR: Momentary interruption
    NORMAL: Normal
    		-
    Deceleration Open
    		Acceleration sensor open detection/ERROR or NORMAL
    		ERROR: Momentary interruption
    NORMAL: Normal
    		-
    Steering Open
    		Steering angle sensor open detection/ERROR or NORMAL
    		ERROR: Momentary interruption
    NORMAL: Normal
    		-
    Master Cylinder Open
    		Master cylinder pressure sensor
    open detection/ERROR or NORMAL
    		ERROR: Momentary interruption
    NORMAL: Normal
    		-
    IG Voltage Value Decreased
    		IG voltage value decrease
    detection/ERROR or NORMAL
    		ERROR: Momentary interruption
    NORMAL: Normal
    		-
    IG Voltage Value Increased
    		IG voltage value increase
    detection/ERROR or NORMAL
    		ERROR: Momentary interruption
    NORMAL: Normal
    		-
    FR Speed Sensor Voltage Open
    		Front speed sensor RH voltage
    open detection/ERROR or NORMAL
    		ERROR: Momentary interruption
    NORMAL: Normal
    		-
    FL Speed Sensor Voltage Open
    		Front speed sensor LH voltage
    open detection/ERROR or NORMAL
    		ERROR: Momentary interruption
    NORMAL: Normal
    		-
    RR Speed Sensor Voltage Open
    		Rear speed sensor RH voltage
    open detection/ERROR or NORMAL
    		ERROR: Momentary interruption
    NORMAL: Normal
    		-
    RL Speed Sensor Voltage Open
    		Rear speed sensor LH voltage
    open detection/ERROR or NORMAL
    		ERROR: Momentary interruption
    NORMAL: Normal
    		-
    M/C Pressure Sensor Noise
    		Master cylinder pressure sensor
    noise detection/ERROR or NORMAL
    		ERROR: Momentary interruption
    NORMAL: Normal
    		-
    Yaw Rate Sensor Voltage Open
    		Yaw rate sensor voltage open
    detection/ERROR or NORMAL
    		ERROR: Momentary interruption
    NORMAL: Normal
    		-
    EFI Communication Invalid
    		EFI communication invalid
    detection/ERROR or NORMAL
    		ERROR: Momentary interruption
    NORMAL: Normal
    		-

  6. While observing the screen, gently jiggle the connector or wire harness between the ECU and sensors, or between ECUs.

    OK:
    ERROR display does not change.
    HINT:
    If the display changes, the connector and/or the wire harness has caused a momentary interruption of the circuit. Repair or replace the connector and/or wire harness as one of them is faulty.