Diagnosis System

DIAGNOSIS SYSTEM

1. DESCRIPTION




a. The hybrid vehicle control ECU has a self-diagnosis system. If the computer, hybrid vehicle control system, or a component is not working properly, the ECU records the conditions that relate to the fault. The ECU also illuminates the master warning light in the combination meter and other appropriate indicators on the multi-information display, such as the HV system warning indicator, the HV battery warning indicator, or the discharge warning indicator.

HINT: The master warning light will illuminate when the THS II fails and the light will blink when in inspection mode.
- When troubleshooting OBD II vehicles, it is necessary to connect an OBD II scan tool that complies with SAE J1978 or connect an intelligent tester to the vehicle. Using one of these testers, it will be possible to 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, (2)the powertrain control components (which affect vehicle emissions), (3)the ECM and hybrid vehicle control ECU. In addition, applicable Diagnostic Trouble Codes (DTCs) prescribed by SAE J2012 are recorded in the hybrid vehicle control ECU memory.If a malfunction does not recur in 3 consecutive trips, the MIL will go off automatically. However, the DTCs will remain recorded in the hybrid vehicle control ECU memory.




- To check for DTCs, connect the intelligent tester to the Data Link Connector 3 (DLC3) with the CAN vehicle interface module (CAN VIM). The intelligent tester also allows erasing of DTCs, viewing of freeze frame data, and viewing of various forms of THS II data (for operating instructions, refer to the tester's instruction manual). 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 the manufacturer within prescribed limits.

2. CHECK DLC3







a. The hybrid vehicle control ECU uses the ISO 9141-2 communication protocol. The terminal arrangement of the DLC3 complies with SAE J1962 and matches the ISO 9141-2 format.

HINT: Connect the cable of the intelligent tester to the DLC3, turn the power switch on (IG), and attempt to use the tester. If the display on the tester indicates that a communication error has occurred, there is a problem either with the vehicle or with the tester.
- If the tester is able to communicate when it is connected to another vehicle, inspect the DLC3 connector of the original vehicle.
- If communication is still not possible when the tester is connected to another vehicle, the problem may be in the tester itself. Consult the tester's instruction manual for information on service or repair of the tester.

3. INSPECT AUXILIARY BATTERY
a. Measure the voltage of the auxiliary battery.

Standard Voltage: 10 to 14 V

b. Inspect the auxiliary battery, fuses, fusible links, wiring harness, connectors and ground.

4. CHECK MIL
a. The MIL will illuminate when the power switch is turned on (IG), before the "READY" light comes on. If the MIL does not illuminate, troubleshoot the MIL circuit.
b. When the "READY" light turns on, the MIL should turn off. If the MIL remains on, the diagnosis system has detected a malfunction or abnormality in the system.