Diagnosis System
L110F HYBRID VEHICLE CONTROL: HYBRID CONTROL SYSTEM: 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 provides other appropriate messages on the multi-information display, such as the HV system warning message, the HV battery warning message, on the discharge warning message.
HINT: The master warning light will illuminate when the THS II malfunctions and the light will blink when in inspection mode.
- When troubleshooting OBD II (On-Board Diagnostics) vehicles, the intelligent tester or Techstream (complying with SAE J1987) must be connected to the DLC3 (Data Link Connector 3) of the vehicle. Various data in the vehicle ECM (Engine Control Module) can then be read.
- OBD II regulations require that the vehicle's on-board computer illuminate the MIL (Malfunction Indicator Lamp) on the instrument panel when the computer detects a malfunction in:
1 The emission control system components.
2 The powertrain control components (which affect vehicle emissions).
3 The computer itself.
In addition, the applicable DTCs prescribed by SAE J2012 are recorded in the hybrid vehicle control ECU memory. If the malfunction does not recur in 3 consecutive trips, the MIL turns off automatically but the DTCs remain recorded in the hybrid vehicle control ECU memory.
- To check for DTCs, connect the intelligent tester or Techstream to the DLC3. The tester displays DTCs, freeze frame data, and a variety of THS II data. The DTCs and freeze frame data can be erased with the tester. In order to enhance the OBD function on vehicles and develop the Off-Board diagnosis system, Controller Area Network (CAN) communication is used in this system. CAN is a network which uses a pair of data transmission lines spanning multiple computers and sensors. It allows for high speed communications between the systems and simplification of the wire harness connections.
Intelligent tester only:
Since this system is equipped with CAN communication, connecting the CAN Vehicle Interface Module (VIM) with the intelligent tester is necessary to display any information from the hybrid vehicle control ECU. Also, communications between the intelligent tester and hybrid vehicle control ECU are performed using CAN communication signals. When confirming DTCs and any data of the hybrid vehicle control ECU, connect the CAN VIM between the DLC3 and intelligent tester.
2. 2 TRIP DETECTION LOGIC
- When a malfunction is first detected, the malfunction is temporarily stored in the hybrid vehicle control ECU memory (1st trip). If the same malfunction is detected during the next drive cycle, the MIL is illuminated (2nd trip).
3. FREEZE FRAME DATA
- The hybrid vehicle control ECU records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, as well as other data recorded at the time of a malfunction.
4. AUXILIARY BATTERY VOLTAGE
Standard voltage:
11 to 14 V
- If voltage is below 11 V, replace or recharge the battery before proceeding.
5. MIL (Malfunction Indicator Lamp)
(a) The MIL is illuminated when the power switch is first turned on (IG), before the READY indicator comes on.
(b) When the READY indicator turns on, the MIL should turn off. If the MIL remains illuminated, the diagnosis system has detected a malfunction or abnormality in the system.
HINT: If the MIL is not illuminated when the power switch is first turned on (IG), check the MIL circuit MIL Circuit.