Diagnosis System
P112 HYBRID VEHICLE CONTROL: HYBRID CONTROL SYSTEM: DIAGNOSIS SYSTEM
DIAGNOSIS SYSTEM
1. DESCRIPTION
(a) 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 malfunctions, and illuminates the master warning light in the combination meter together with indicators on the multi display, the HV system warning, the HV battery warning or the discharge warning.
HINT: The master warning light 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 ISO 15031-4 or the Techstream 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 ISO 15031-4 are recorded in the HV control ECU memory Hybrid Control System.
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 Techstream to the Data Link Connector 3 (DLC3). The Techstream 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 Hybrid Control System.
- Freeze frame data:
The freeze frame data records the driving condition when malfunction is detected. When troubleshooting, it can help determine if the vehicle was moving, braking, stationary, or reversing.
2. CHECK DLC3
The HV control ECU uses the ISO 15765-4 communication protocol. The terminal arrangement of the DLC3 complies with ISO 15031-03 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 power switch, other switches or doors.
If the result is not as specified, the DLC3 may have a malfunction. Repair or replace the harness and connector.
HINT: If the display shows UNABLE TO CONNECT TO VEHICLE when you have connected the cable of the Techstream to the DLC3, turned the power switch ON (IG) and operated the tester, there is a problem on the vehicle side or tester side.
- If communication is normal when the tester or scan tool is connected to another vehicle, inspect the DLC3 on the original vehicle.
- If communication is still not possible when the tester or scan tool is connected to another vehicle, the problem is probably in the tester or scan tool itself, so consult the Service Department listed in its instruction manual.
3. INSPECT AUXILIARY BATTERY
(a) Measure the voltage of the auxiliary battery.
Standard voltage:
11 to 14 V
(b) Inspect the auxiliary battery, fusible links, wire harness, connectors and ground.
4. CHECK MIL
(a) The MIL illuminates when the power switch is turned ON (IG) and the "READY" light is OFF.
If the MIL is not illuminated, troubleshoot the MIL circuit 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.