Description of On-Board Diagnostics
DIAGNOSIS SYSTEMDESCRIPTION
When troubleshooting a vehicle with the diagnosis system, the only difference from the usual troubleshooting procedure is connecting the intelligent tester to the vehicle and reading various data output from the vehicle's clearance warning ECU.
The clearance warning ECU records DTCs when the ECU detects a malfunction in the ECU itself or in its circuits. To check the DTCs, connect the intelligent tester to the DLC3 on the vehicle. The intelligent tester enables you to erase the DTCs, activate the various actuators, and check the freeze frame data and Data List.