LEMON Manuals: Even more car manuals for everyone
Home >> Scion >> 2013 >> FR-S Standard Trans >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Communication Devices >> Can Communication System (Diagnostics & Symptom Tests) >> Can Communication System >> Symptom Tests >> Open in One Side of CAN Branch Line [05/2013 - ] >> Description

Open in One Side of CAN Branch Line [05/2013 - ]: Description

If an ECU or sensor is not displayed on the CAN Bus Check screen of the Techstream and some ECUs and sensors repeatedly appear and disappear from the screen when the CAN main bus lines are normal (there is no open, short, short to +B or short to GND in the main bus lines), there may be an open circuit in either of one pair of CAN branch lines.

HINT: 

If some ECUs and sensors repeatedly appear and disappear from the CAN Bus Check screen, communication between the normal ECUs (sensors) and the Techstream may be affected by the incomplete signals that are output from the ECU that has an open circuit in either of its CAN branch lines. In this case, the CAN branch lines for the ECUs and sensors that repeatedly appear and disappear from the screen are normal and the ECU that is not displayed on the screen may be the main cause of the problem (this ECU may have an open circuit in either of its CAN branch lines).

Symptom Trouble Area
2 or more ECUs and/or sensors do not appear on the Techstream "CAN Bus Check" screen. One side of CAN branch line is open, or output signals are incomplete.
  • Short in CAN main bus line
  • Short in CAN branch line
  • Main body ECU (network gateway ECU)
  • Combination meter assembly
  • Certification ECU (smart key ECU assembly)*1
  • ECM
  • TCM*2
  • Skid control ECU (brake actuator assembly)
  • Steering angle sensor (spiral cable sub-assembly)
  • Power steering ECU assembly
  • Air conditioning control assembly*3
  • Air bag ECU assembly

*1: w/ Smart Key System

*2: for Automatic Transmission System

*3: for Automatic Air Conditioning System