General Information

INTRODUCTION: HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS: GENERAL INFORMATION

GENERAL INFORMATION
- A large number of ECU controlled systems are used in this vehicle. In general, ECU controlled systems are considered to be very intricate, requiring a high level of technical knowledge to troubleshoot. However, most problem checking procedures only involve inspecting the ECU controlled system's circuits one by one. An adequate understanding of the system and a basic knowledge of electricity is enough to perform effective troubleshooting, accurate diagnoses and necessary repairs.
- FOR USING Techstream*
HINT: *: Techstream is the name for the diagnostic tester in North America.

- Before using Techstream, read the operator's manual thoroughly.
- If Techstream cannot communicate with the ECU controlled systems when Techstream is connected to the DLC3 with the ignition switch on (IG) and Techstream turned on, there is a problem on the vehicle side or Techstream side.
1. If communication is normal when Techstream is connected to another vehicle, inspect the diagnosis data link line (Bus (+) line) or ECU power circuit of the vehicle.
2. If communication is still not possible when Techstream is connected to another vehicle, the problem is probably in Techstream itself. Perform the Self Test procedures outlined in the Techstream operator's manual.

1. DESCRIPTION
(a) Each system data and the Diagnostic Trouble Codes (DTCs) can be read from the Data Link Connector 3 (DLC3) of the vehicle. When the system seems to be malfunctioning, use Techstream to check for malfunctions and perform repairs.
2. CHECK DLC3






(a) The vehicle's ECU uses the ISO 15765-4 communication protocol. The terminal arrangement of the DLC3 complies with SAE J1962 and matches the ISO 15765-4 format.





NOTE: *: Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the ignition switch, any other switches, or the doors.
If the result is not as specified, the DLC3 may have a malfunction. Repair or replace the harness and connector.

HINT:
- If communication is normal when Techstream is connected to another vehicle, inspect the DLC3 on the original vehicle.
- If communication is still not possible when Techstream is connected to another vehicle, the problem is probably in the tester itself. Consult the Service Department listed in Techstream's instruction manual.