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OBDC
On Board Diagnostics (OBD) is a series of standards from the California Air Resources Board (CARB), and is being introduced in two phases.
The first (OBD I), introduced in 1988, covered such things as EGR and oxygen sensor failure, and out-of-range sensor signal. The second phase (OBD II), is being introduced during 1994-1996 and covers 9 specific areas of vehicle operation which may have an impact on the environment.
1. Engine Misfire Increases HC, CO emmisions
2. Catalyst efficiency Reduced catalyst efficiency
increases all emissions
3. Oxygen (lambda) sensor Emission control cannot function
in closed loop mode hence more emissions
4. Fuel injection system Defective system may cause a rise in
emissions
5. Evaporative purge system May cause a rise in HC emissions
6. Sensors and actuators May cause emissions increase (in OBD I)
7. Air conditioning system Refrigerants damage atmosphere
8. Exhaust gas recirculation (EGR) Failure results in increased NOx
emissions
9. Secondary air system Increased emissions during warm up phase
My understanding is that if a fault is indicated by a dashboard light, it will be an offence to use the vehicle until the fault is rectified.
OBD II also covers standardisation of diagnostic fault codes and tools, so, here's the good news, one piece of (££££) diagnostic kit will cover all makes of vehicle - I'll believe this only when I see it!
I guess it will only be a matter of time before this standard (or derivatives of it) are adopted here in the UK as well.
Remember the days when the only piece of electronics required to tune a car was a timing light?
Steve
__
Steve Evans Radstone Technology Plc.
Principal Design Engineer Water Lane,
Towcester,
Tel: +44 (0) 1327 359444 Northants,
Fax: +44 (0) 1327 358113 NN12 6JN
Email: sevans@radstone.co.uk ENGLAND