CHINA NATIONWIDE STAGE 6
When troubleshooting On-Board Diagnostic (OBD) vehicles, an OBD scan tool (complying with ISO 15765-4) must be connected to the vehicle. Various data output from the vehicle ECM can then be read.
OBD regulations require that the vehicle on-board computer illuminate the Malfunction Indicator Lamp (MIL) on the instrument panel when the computer detects a malfunction in:
The emission control system/components
The powertrain control components which affect vehicle emissions
The computer
In addition, the applicable Diagnostic Trouble Codes (DTCs) prescribed by ISO 15765-4 are recorded in the ECM memory.
If the malfunction does not recur in 3 consecutive trips, the MIL turns off automatically but the DTCs will remain recorded in the ECM memory.
To check for DTCs, connect the GTS to the Data Link Connector 3 (DLC3) of the vehicle. The GTS displays DTCs, freeze frame data and a variety of engine data.
The DTCs and freeze frame data can be cleared with the GTS.
NORMAL MODE AND CHECK MODE (GTS Only)
The diagnosis system operates in normal mode during normal vehicle use. In normal mode, 2-trip detection logic is used to ensure accurate detection of malfunctions. Check mode is also available to technicians as an option. In check mode, 1-trip detection logic is used when reproducing malfunction symptoms for increasing the ability of the system to detect malfunctions, including intermittent malfunctions.
2-TRIP DETECTION LOGIC
When a malfunction is first detected, the malfunction is temporarily stored in the ECM memory (1st trip). If the same malfunction is detected during the subsequent driving cycle, the MIL is illuminated (2nd trip).
FREEZE FRAME DATA
The ECM 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 moving or stationary, whether the engine was warmed up or not and whether the air-fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.
The GTS displays freeze frame data recorded at five different points: 1) 3 times before the DTC is stored, 2) once when the DTC is stored, and 3) once after the DTC is stored. The data can be used to reproduce the vehicle condition around the time of the malfunction. The data may be helpful in determining the cause of a malfunction. It may also be helpful in determining whether a DTC is being caused by a temporary malfunction.
LIST OF FREEZE FRAME DATA
| Tester Display |
|---|
| Total Distance Traveled |
| Total Distance Traveled - Unit |
| Vehicle Speed |
| Engine Speed |
| Calculate Load |
| Coolant Temperature |
| Intake Air Temperature |
| Ambient Temperature |
| Engine Run Time |
| Battery Voltage |
| BATT Voltage |
| Glow Indicator Supported |
| Throttle Position Sensor No.1 Voltage % |
| Starter SW |
| Neutral Position SW |
| Stop Light SW |
| Cruise Main SW |
| TC Terminal |
| MIL ON Run Distance |
| Running Time from MIL ON |
| Time after DTC Cleared |
| Distance from DTC Cleared |
| Warmup Cycle Cleared DTC |
| Accel Position from EFI |
| NT Sensor Speed |
| NIN Sensor Speed |
| NOUT Sensor Speed |
| NOUT Sensor Voltage |
| Belt Clamping Force Sensor |
| Shift SW Status (P Range) |
| Shift SW Status (R Range) |
| Shift SW Status (N Range) |
| Shift SW Status (N,P Range) |
| Shift SW Status (N,P Range) Supported |
| Shift SW Status (S Range) |
| Shift SW Status (D Range) |
| A/T Oil Temperature No.1 |
| ATF Thermal Degradation Estimate |
| CVT Oil Press Calibration |
| NT Sensor Voltage |
| Lock Up Status |
| CVT Shift Status Ratio |
| Solenoid (SLU) |
| Solenoid (SLS) High/Low |
| Solenoid (SLS) MAX/MIN |
| Solenoid (SLP) |
| Solenoid (SL) |
| Solenoid (SC) |
DATA LINK CONNECTOR 3 (DLC3)
BATTERY VOLTAGE
11 to 14 V
If the voltage is below 11 V, recharge or replace the battery.
MIL (Malfunction Indicator Lamp)
The MIL is illuminated when the ignition switch is turned to ON (with the engine not running).
If the MIL does not illuminate, check the MIL circuit.
The MIL will turn off when the engine is started. If the MIL remains illuminated, the diagnosis system has detected a malfunction or abnormality in the system.