Check For Intermittent Problems [09/2015 - 08/2019]

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 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 interruptions 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 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.

   Chassis > ABS/VSC/TRAC/EPB > 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: Momentary interruption 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: 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 wire harness between skid control ECU (brake actuator assembly) and stop light switch assembly status	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, 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.