CANH and CANL branch lines of the DLC3 and the ECU power source circuits (in this case perform steps 7
to 9 first). In addition, check that the BAT terminal of the DLC3 receives battery voltage (11 V or more).
If communication between the Techstream and ECUs is still not possible even when the Techstream is
connected to another vehicle, the Techstream has a malfunction. Perform the self tests described in the
Techstream operators manual. (The Techstream may be malfunctioning or its battery may be discharged.)
OK (Communication between the Techstream and the vehicle is possible.) A
OK (Communication between the Techstream and the vehicle is not possible but communication is
possible when connected to another vehicle.)
NG (Communication is not possible between the Techstream and the vehicle, nor between the
Techstream and another vehicle.)
Go to step 7
Refer to Techstream operator's manual
4. CHECK DTC
(a) Using the Techstream, perform Health Check to read current and history DTCs and record them.
AN communication DTCs are output when there is an open or short in any of the communication lines.
Any problems with the power source of a corresponding ECU or sensor, or problems in the ECU or sensor
itself also cause these DTCs to be output.
If a CAN communication line connector is disconnected with the ignition switch ON, the ECUs of the
corresponding system and related systems store a DTC.
If an open in a CAN main bus line, a short between the CAN bus lines (CANH and CANL) or a +B or ground
short in a CAN bus occurs, DTCs of almost all ECUs and sensors on the CAN bus may be output (or a
message indicating a communication error may be displayed on the Techstream screen). In this case,
check the resistance of the CAN bus (steps 7 to 9) first.
If an open occurs in just one of the lines of a CAN branch, DTCs which are not related to malfunctioning
parts may be output (DTCs may be displayed randomly), or a message indicating a communication error
may be displayed on the Techstream.
(b) Read the freeze frame data using the Techstream and record it.