Diagnosis System

DIAGNOSIS SYSTEM










The HV control ECU has a self-diagnosis system. If the computer, hybrid vehicle control system or the components are not working properly, the ECU carries out a diagnosis to detect the malfunction, and illuminates the master warning lamp in the combination meter together with any of indicators on the multi-information display, the HV system warning, the HV battery warning or the discharge warning.

HINT: The master warning lamp illuminates when THS II fails and it blinks when in inspection mode.

- When troubleshooting OBD II vehicles, the only difference from the usual troubleshooting procedure is that you need to connect the OBD II scan tool complying with SAE J1978 or the hand-held tester to the vehicle, and read various data output from the vehicle's ECUs.
- OBD II regulations require that the vehicle's on-board computer illuminates the Malfunction Indicator Lamp (MIL) in the instrument panel when the computer detects a malfunction in:
1. the emission control systems/components, or
2. the powertrain control components (which affect vehicle emissions), or
3. the computers. In addition, the applicable Diagnostic Trouble Codes (DTCs) prescribed by SAE J2012 are recorded in the HV control ECU memory (see Trouble Code Descriptions).

If the malfunction does not recur in 3 consecutive trips, the MIL will go off automatically. However the DTCs remain recorded in the HV control ECU memory.




- To check the DTCs, connect the hand-held tester to the Data Link Connector 3 (DLC3) with the CAN vehicle interface module (CAN VIM). Or, connect the OBD II scan tool to the DLC3. The hand-held tester or OBD II scan tool also enables you to erase the DTCs and check the freeze frame data and various forms of THS II data (for operating instructions, refer to their respective instruction manuals). The DTCs include SAE controlled codes and manufacturer controlled codes. SAE controlled codes must be set as prescribed by the SAE, while manufacturer controlled codes can be set by a manufacturer within the prescribed limits (see the DTC chart on Trouble Code Descriptions).
- Freeze frame data:
The freeze frame data record the driving condition when malfunction is detected. When troubleshooting, it can help determine if the vehicle was moving, braking, stationary, or reversing.