Check For Intermittent Problems [11/2017 - 03/2019]

HINT: 

A momentary interruption (open circuit) in the connectors and/or wire harness between the sensors and ECUs can be detected using the Data List function of the Techstream.

1. Turn the engine switch off.
2. Connect the Techstream to the DLC3.
3. Turn the engine switch on (IG).
4. Turn the Techstream on.
5. Follow the directions on the Techstream 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 engine switch is turned on (IG) (initial check).
   • If Error remains displayed for one of the items on the Techstream, check for continuity between the ECU and the item for which Error is displayed.
   • If a momentary interruption occurs and Error is displayed on the Techstream, Error will remain displayed on the Techstream for 1 second after the circuit returns to normal.

   Chassis > ABS/VSC/TRAC > Data List 

   Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
   FR Speed Open	Front speed sensor RH open detection	Error or Normal	Error: Momentary interruption Normal: Normal	-
   FL Speed Open	Front speed sensor LH open detection	Error or Normal	Error: Momentary interruption Normal: Normal	-
   RR Speed Open	Rear speed sensor RH open detection	Error or Normal	Error: Momentary interruption Normal: Normal	-
   RL Speed Open	Rear speed sensor LH open detection	Error or Normal	Error: Momentary interruption Normal: Normal	-
   EFI Communication Open	ECM 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	-
   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: Malfunction Normal: Normal	-
   Brake Pedal Switch Open	Brake pedal load sensing switch open 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	ECM communication invalid detection	Error or Normal	Error: Invalid Normal: Normal	-
   Vertical Acceleration Sensor Open	Momentary interruption (open circuit) status in the wire harness between the skid control ECU (brake actuator assembly) and the roll rate and vertical acceleration sensor (yaw rate sensor)	Error or Normal	Error: Momentary interruption Normal: Normal	-
   Master Cylinder Pressure Sensor Power Supply Open	Master cylinder pressure sensor power supply voltage status	Error or Normal	Error: Momentary interruption Normal: Normal	-
   Solenoid Power Supply Open	Solenoid power supply voltage status	Error or Normal	Error: Momentary interruption Normal: Normal	-
   Motor Power Supply Open	Motor power supply voltage status	Error or Normal	Error: Momentary interruption Normal: Normal	-
   Stop Switch Open	Momentary interruption (open circuit) status in the wire harness between skid control ECU (brake actuator assembly) and the stop light switch assembly	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

   Normal is displayed.

   HINT: 

   If the display changes, this indicates that there has been a momentary interruption (open circuit) in the connector and/or wire harness. In this case, repair or replace the connectors and/or wire harnesses as one of them is faulty.