HINT:

• If the ignition switch can be turned ON (the power source mode can be changed to ON) when the vehicle is brought in for repair, check for DTCs and check the illumination condition of the indicators in the combination meter assembly and the basic operation of the vehicle (such as steering operation) promptly.
• Do not turn the ignition switch off until the inspection of the vehicle is finished, as some fail-safe functions are canceled when the ignition switch is turned off.
• If the ignition switch cannot be turned ON (the power source mode cannot be changed to ON) when the vehicle is brought in, measure the voltage of the battery. If the voltage is below 11 V, recharge or replace the battery before performing troubleshooting.

HINT:

• When troubleshooting, confirm that the problem symptoms have been accurately identified. Preconceptions should be discarded in order to make an accurate judgment. To clearly understand what the problem symptoms are, it is extremely important to ask the customer about the problem and the conditions at the time the malfunction occurred.
• Ask the customer if the vehicle is/was equipped with additional devices such as a theft deterrent device or monitor. (If equipped, explain to the customer that the additional devices will be removed before performing troubleshooting as the malfunction cannot be checked properly.)
• Examples of points to be confirmed are shown below.

HINT:

• What was affected (system, part or meter warning indicators)
• What happened (details of the malfunction)
• When (occurrence date and time, frequency and if it recurs or not)
• Under what kind of situation did the problem occur (driving and operating condition at the occurrence and weather)
• Road type or condition (city, suburb, paved road, unpaved road, highway, etc.)
• Return conditions (what made the vehicle return to normal, for example, the ignition switch was turned off)

HINT:

• If communication is not possible, the Techstream screen will indicate an error.
• If communication between the Techstream and ECUs is not possible, either the Techstream or vehicle has a malfunction.
• When communication between the Techstream and the vehicle is not possible, but communication is possible when the Techstream is connected to another vehicle, the vehicle is malfunctioning. Inspect the CANH and CANL branch lines of the DLC3 and the ECU power source circuits (in this case perform steps 25 to 26 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 operator's manual. (The Techstream may be malfunctioning or its battery may be discharged.)

HINT:

• If an open in a CAN main bus line, a short between the CAN bus lines (CANH and CANL) or a short to ground or +B 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 10 to 18) first.
• If an open occurs in just one of the wires of a CAN branch line, 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.

HINT:

• If an open in a CAN main bus line, a short between the CAN bus lines (CANH and CANL) or a short to ground or +B 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 10 to 18) first.
• If an open occurs in just one of the wires of a CAN branch line, 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.

HINT:

• Regarding CAN Bus Check, refer to How to Interpret CAN Bus Check Screen.

  Click here

• If the detection status of any ECU changes during the inspection, one of the branch lines of a connected ECU or sensor may be open. (Signals from the ECU or sensor that has an open in one of its branch lines create electrical noise, affecting response to the Techstream and whether or not the ECUs and sensors are displayed.)
• Regarding the ECUs connected to sub bus 1, the main body ECU (multiplex network body ECU) displays communicating ECUs on the Techstream. If the communication between the main body ECU (multiplex network body ECU) and an ECU stops for 10 seconds or more, the ECU will no longer be displayed on the Techstream.
• Regarding the communication stop mode for ECUs connected to sub bus 1, refer to the inspection procedure for the DTCs that indicate a communication stop.

HINT:

• The term "sub bus monitor ECU" refers to a gateway function equipped ECU that is able to monitor a bus and store DTCs.
• When checking for communication DTCs, refer to How to Interpret Communication DTCs (DTCs that start with U).

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• Because a gateway function equipped ECU (sub bus monitor ECU) monitors signals from all ECUs that are connected to its sub bus, a gateway function equipped ECU can detect ECUs with a communication stop more accurately. In this case, perform troubleshooting by referring to the DTC combination table for the sub bus.

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• If communication DTCs are stored, and all ECUs and sensors connected to the CAN communication system are displayed on the CAN Bus Check screen of the Techstream, a past malfunction that is currently not occurring is suspected.
• When a CAN branch of the bus 2, bus 3 and bus 5 is malfunctioning, because the ECUs and sensors related to it detect the malfunction, the problem area can be determined using the combination of DTCs that are output.
• When sub bus 1 is malfunctioning, the main body ECU (multiplex network body ECU) detects a communication stop for connected ECUs and a network communication error, and stores DTCs.
• On the Techstream, the Main Body item displays the DTCs for ECUs connected to sub bus 1.
• When both the sub bus monitor ECU and the ECUs connected to the bus 2, bus 3 or bus 5 store communication DTCs, check and repair the corresponding sub bus first.