06-03-2013, 03:29 PM
ON BOARD DIAGNOSIS SYSTEM (ENGINE FAULT DIAGNOSIS AND MAINTENANCE)
BOARD DIAGNOSIS.pptx (Size: 735.39 KB / Downloads: 32)
WHAT IS OBD ?
On Board Diagnostics with a Check Engine Light
Mandated by CARB
Gave birth to OBD II
WHAT IS OBD II ?
On Board Diagnostics II
Response to Federal Government
Monitors when emissions increase by 50% percent or more.
Calls for standard service procedure without dedicated special tools.
Universal Diagnostic Test connector
Standard list of Diagnostic Trouble codes
FEATURES OF OBD II
Continuous monitoring and once per trip function check
Enhanced oxygen sensor diagnostic
Enhanced fuel trim diagnostic
Engine misfire detection
Catalyst efficiency monitor
EGR flow monitor
Evaporative purge flow meter
COMPONENTS OF OBD SYSTEM
ECM (ENGINE CONTROL MODULE)
DTC(DAGNOSIS TROUBLE CODE)
MIL(MALFUNCTION INDICATOR LAMP/LIGHT)
ENGINE CONTROL SENSORS
MONITORING SYSTEM
DLC(DATA LINK CONNECTOR)
SCAN TOOL
SCAN TOOL
DTC reading and explanation.
DTC erasing.
Live time Current Data (in digits and in graphic modes).
Actuation test.
Item graphic view.
Current data recording function.
Sensor simulation mode.
System Identification (ECU number)
Service reset function.
ECU re-programming.
OBD-I, OBD-II, Euro OBD, CAN communication support.
BENIFITS
Improved air quality
Early detection and repair of minor problems that may prevent more significant, more costly repairs later.
Accurate diagnosis that leads to essential, cost-effective repairs.
Early vehicle maintenance opportunity, which leads to greater fuel efficiency and reliability, and potentially less engine wear and tear.
Short inspection time for the public since the OBD test is part of vehicle safety inspection, minimizing inspection time and maximizing cost-effectiveness.
Incentive to car manufacturers to produce more durable engines and emission controls.
State-of-the-art evaporative emission detection, eliminating evaporative emissions as well as exhaust emissions.
CONCLUSION
Since OBD II systems monitor vehicle performance while the vehicle is being operated, OBD II systems also provide real-time diagnostic information. The OBD II system stores emission information plus engine operating conditions and parameters. These performance measurements and the reporting of that performance via stored codes provides a repair technician with on-road engine parameter data that may not be available via the older style tests that were conducted at most repair facilities
One of the basic pillars of the OBD II system, compared to its predecessors, is standardization. The standard items include fault codes, communication protocol, connection hardware, and the scan tools used to check the system. This standardization allows the universal application of OBD II system diagnosis to all makes and models. Standardization also allows a reduction in the complexity and cost of the I/M test equipment.