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: 

   • A momentary interruption (open circuit) cannot be detected for 3 seconds after the ignition switch is turned to ON (initial check).
   • If the Error display remains displayed, measure the resistance between the ECUs and sensors, or between ECUs.
   • 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/Normal or Error	Normal: Normal Error: Momentary interruption	-
   FL Speed Open	FL speed sensor open detection/Normal or Error	Normal: Normal Error: Momentary interruption	-
   RR Speed Open	RR speed sensor open detection/Normal or Error	Normal: Normal Error: Momentary interruption	-
   RL Speed Open	RL speed sensor open detection/Normal or Error	Normal: Normal Error: Momentary interruption	-
   EFI Communication Open	EFI communication open detection/Normal or Error	Normal: Normal Error: Momentary interruption	-
   Yaw Rate Open	Yaw rate sensor open detection/Normal or Error	Error: Momentary interruption Normal: Normal	-
   Deceleration Open	Acceleration sensor open detection/Normal or Error	Normal: Normal Error: Momentary interruption	-
   Steering Open	Steering angle sensor open detection/Normal or Error	Normal: Normal Error: Momentary interruption	-
   Master Cylinder Open	Master cylinder pressure sensor open detection/Normal or Error	Normal: Normal Error: Momentary interruption	-
   IG Voltage Value Decreased	IG voltage value decrease detection/Normal or Error	Normal: Normal Error: Momentary interruption	-
   IG Voltage Value Increased	IG voltage value increase detection/Normal or Error	Normal: Normal Error: Momentary interruption	-
   FR Speed Sensor Voltage Open	Front speed sensor RH voltage open detection/Normal or Error	Normal: Normal Error: Momentary interruption	-
   FL Speed Sensor Voltage Open	Front speed sensor LH voltage open detection/Normal or Error	Normal: Normal Error: Momentary interruption	-
   RR Speed Sensor Voltage Open	Rear speed sensor RH voltage open detection/Normal or Error	Normal: Normal Error: Momentary interruption	-
   RL Speed Sensor Voltage Open	Rear speed sensor LH voltage open detection/Normal or Error	Normal: Normal Error: Momentary interruption	-
   M/C Pressure Sensor Noise	Master cylinder pressure sensor noise detection/Normal or Error	Normal: Normal Error: Momentary interruption	-
   Yaw Rate Sensor Voltage Open	Yaw rate sensor voltage open detection/Normal or Error	Normal: Normal Error: Momentary interruption	-
   EFI Communication Invalid	EFI communication invalid detection/Normal or Error	Normal: Normal Error: Momentary interruption	-
   Body ECU Communication open	Status of the Body ECU communication open detection/Normal or Error	Normal: Normal Error: Momentary interruption	-

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.