Application Note / FMS On-Board Diagnostics Overview This white paper clarifies the OBDII compatibility of Fleet Management Solutions (FMS) hardware with vehicles in North America, European Union, and other regions. To help you determine if your vehicle is OBDII compliant, this paper presents a summary of the various diagnostic systems and a guide to determining which system is currently in use. Determine OBDII Compatibility Overview of OBDII, J1708, and J1939 Diagnostic Systems OBDII, J1708, and J1939 are the different types of onboard diagnostic systems installed in vehicles.
Each vehicle has one particular system and uses the language of that system to report diagnostics. » OBDII: All cars and light trucks built and sold in the United States after January 1, 1996 were required to be OBDII equipped. In general, this means all 1996 model year cars and light trucks are compliant, even if built in late 1995.
The FMS OBDII interface supports all OBDII protocols. » J1708/J1587: This is the standard and predominant diagnostic protocol developed by the Society of Automotive Engineers (SAE) for heavy-duty (and some medium-duty) vehicles and heavy equipment built after 1985. » J1939/CAN: J1939 is a Controller Area Network (CAN) protocol and can be considered the replacement for ... more. less.
the older SAE J1708 and SAE J1587 specifications.<br><br> For the next several years, new heavy duty trucks, and heavy equipment, will have both the J1708 and J1939 interfaces available on the Engine Control Module (ECM). www.fmsgps.com 1 August 2009 Connectors, truck classification and weight classes are commonly used to help determine which diagnostic system is used on any given vehicle. Each are covered below.<br><br> Diagnostic Connectors One way to determine the interface type is to verify which connector the vehicle uses: Which Diagnostic System Does My Vehicle Use? The six-pin connector interfaces to the J1708 protocol and the nine-pin connector interfaces to the J1708/J1939 protocol. Figure 3 illustrates the OBDII connector.<br><br> The following link provides a Vehicle OEM Data Base that may be helpful in determining connector location: http://www.obdclearinghouse.com/ Truck Classification Another way to determine the type of interface in the vehicle/equipment is by vehicle classification. There are two classifications most applicable to trucks: 1. Weight classes, as defined by the US government, ranging from Class 1 to Class 8 2.<br><br> The following broader categories: » Light Duty Truck (class 1-2): < 10,000 lb GVW (Gross Vehicle Weight) = OBDII » Medium Duty Truck (class 3-6): 10,001 326,000 lb GVW = OBDII » Heavy Duty Truck (class 7-8): >26,000 lb GVW = J1708/J1939 Figure 1. J1708 6-Pin Connector Figure 2. J1708/J1939 9-Pin Connector Figure 3.<br><br> OBDII 16-Pin Connector www.fmsgps.com 2 Weight Classes Weight classes are defined by the US government and are used consistently throughout the industry. They are based on the truck's Gross Vehicle Weight Rating (GVWR), or in the trucking industry on GVW plus average cargo weight. Categories, on the other hand, are not as well defined.<br><br> The same truck may be considered a heavy duty truck by one segment of the industry, and a medium duty truck by another. Our research shows that the most often used official categories are derived from the US Department of Transportation (DOT) Vehicle Inventory and Use Survey (VIUS). We indicate the VIUS truck categories in the fourth table column below.<br><br> However, service shops, truckers, and insurance companies define some category boundaries differently than VIUS; therefore, in the last column we have included the commonly used categories. * VIUS: US DOT Vehicle Inventory and Use Survey Weight Class Minimum GVWR (lbs) Maximum GVWR (lbs) VIUS* Category Common Category Class 1 6,000 Light-Duty Light-Duty Class 2 6,001 10,000 Light-Duty Light-Duty Class 3 10,001 14,000 Medium-Duty Light-Duty Class 4 14,001 16,000 Medium-Duty Medium-Duty Class 5 16,001 19,000 Medium-Duty Medium-Duty Class 6 19,501 26,000 Light-Duty Medium-Duty Class 7 26,001 33,000 Heavy-Duty Heavy-Duty Class 8 33,001 Heavy-Duty Heavy-Duty www.fmsgps.com 3 Examples In the table below, we have listed common truck models and their classifications (based on published manufacturer data available on 10/3/2005). Weight Class » 1 2 3 4 5 6 7 8 Common Category » Light Medium Chevrolet Silverado 1500 2 Chevrolet Silverado 2500HD 2 Chevrolet Silverado 3500 2 3 Chevrolet Silverado 3500 4 5 Chevrolet Kodiak C5500 4 5 6 Chevrolet Kodiak C6500 6 Chevrolet Kodiak C7500 6 7 8 Chevrolet Kodiak C8500 7 8 Dodge RAM 1500 2 Dodge RAM 2500 2 Dodge RAM 3500 2 3 Ford F-150 2 Ford F-250 2 Ford F-350 3 Ford F-450 4 Ford F-550 5 Ford F-650 6 7 Ford F-750 7 GMC Sierra 1500 2 GMC Sierra 2500HD 2 GMC Sierra 3500 2 3 GMC TopKick C4500 4 5 GMC TopKick C5500 4 5 6 GMC TopKick C6500 6 GMC TopKick C7500 6 7 8 GMC TopKick C8500 7 8 Heavy www.fmsgps.com 4 There are several ways to determine if a vehicle is OBDII compliant: by year and location, by Emission Control Information, by country of manufacture, or by testing.<br><br> Year and Location » 1996 or newer model year light/medium duty vehicles sold in the United States United States legislation requires all cars and light trucks model year (MY) 1996 and newer to be OBDII compliant. More information is available on the EPA's website. » 2001 or newer model year gasoline vehicle sold in the European Union Commission Directive 70/220/EEC, Annex I: 8.1.<br><br> Vehicles with positive-ignition engines Note that here cEuropean Union d means countries which were members of the EU in 2000. » 2004 or newer model year diesel vehicle sold in the European Union Commission Directive 70/220/EEC, Annex I: 8.2. Vehicles with compression-ignition engines Note that here cEuropean Union d means countries which were members of the EU in 2003.<br><br> Emission Control Information If your vehicle does not fall into any of the above categories, look under the hood and try to locate a label (Figure 4) that explicitly states that the vehicle was designed to comply with OBDII legislation. In this case, OBDII is used as a general term and can mean any of the following: » OBDII (California ARB) » EOBD (European OBD) » JOBD (Japanese OBD) Is My Vehicle OBDII Compliant? Figure 4.<br><br> Vehicle Emission Control Information Label www.fmsgps.com 5 You may also consult your vehicle's owner's manual and perhaps contact your local dealer. However, be aware of the fact that many dealers do not know the difference between OBD and OBDII. If the vehicle is not OBDII compliant, you cannot use a FMS OBDII modem in your vehicle.<br><br> You must purchase a non-OBDII modem and connect constant power and ignition. Country of Manufacture For countries where vehicles are imported, the Vehicle Identification Number (VIN) may also be helpful in determining OBDII compatibility. The first few characters in the VIN define the country of manufacture and given the above information about the country can help determine compliance.<br><br> The following link provides a free VIN decoder that is very useful: http://www.analogx.com/contents/vinview.htm Testing for OBDII Compliance If there is a question as to the vehicles compatibility, purchase an inexpensive OBDII device from ScanTool ( ScanTool.net ) such as the ElmScan 5 or equivalent. This compact and durable tool supports all OBDII protocols, features automatic protocol detection, and ships with a number of compatible diagnostic programs. But my car has the 16-pin OBD connector, shouldn't it be OBDII compliant?<br><br> No, not necessarily. A lot of European and Asian manufacturers equipped their vehicles with D-shaped 16-pin connectors long before they began installing OBDII systems on those vehicles. One curious thing to note here is the fact that most non-OBD compliant vehicles had a Data Link Connector (DLC) that does not fully conform to SAE J1979.<br><br> Compare Figure 5 and Figure 6, and notice the cears d on the non-OBD compliant Ford Focus. Figure 5. Ford Escort Data Link Connector Figure 6.<br><br> OBDII Vehicle Connector, Type A www.fmsgps.com 6 Which OBDII protocol does my vehicle use? Compatibility and compliance can become very problematic especially with some vehicles in countries without any mandates as to compliance. The same vehicle year and model be OBDII compliant in the US, but not in other countries.<br><br> An OBDII compliant vehicle can use any of the five communication protocols: J1850 PWM, J1850 VPW, ISO9141-2, ISO14230-4 (also known as Keyword Protocol 2000), and more recently, ISO15765-4/SAE J2480 (also known as CAN). As a general rule, you can determine which protocol your vehicle is using by looking at the pinout of the connector: In addition to pins 2, 7, 10, and 15, the connector should have pins 4 (Chassis Ground), 5 (Signal Ground), and 16 (Battery Positive). As a rule of thumb, you can usually go by the following to determine which protocol your vehicle uses: If your vehicle has this style connector, but doesn't have these pins populated, you probably have a pre-OBDII vehicle.<br><br> To add some confusion, even having the connector with the contacts shown above is not a guarantee of OBDII compliance. This style connector has been seen on some pre-1996 vehicles which were not OBDII compliant. Protocol Pin 2 Pin 6 Pin 7 Pin 10 Pin 14 Pin 15 J1850 PWM Must have Must have J1850 VPW Must have ISO9141/14230 Must have May have ISO15765 (CAN) Must have Must have Ford = PWM General Motors = VPW European/Chrysler = ISO www.fmsgps.com 7 Your vehicle should be compliant if one or more of the following is true: » e 1996 cars and light trucks in United States » e 2001 gas in European Union » e 2004 diesel in European Union » VIN information meets the above criteria » Emission control label states OBDII certification » Compatible with an OBDII diagnostic tool (such as the ElmScan 5) If the vehicle is OBDII compliant, then the FMS OBDII compatible modem should work without trouble.<br><br> The modem will automatically detect the protocol and communicate over the correct signals in the OBDII connector. If the vehicle is not compliant and you have purchased an FMS OBDII modem, then use the outline below to determine the next step. MLT-400iO (Iridium Modem): » Replace with a non-OBDII modem such as the MLT-400i, or » Disconnect the OBDII connector and connect power, ignition wires, and antenna cables (see the Installation Guide for more details) and then contact FMS technical support team to issue the Reset Configuration Command.<br><br> If you are using a Message Display Terminal (MDT-PRO), you must also connect both the modem AND the MDT (using the two pin connector) to the same power source in addition to performing the steps above. MLT-325oO (Orbcomm Modem): » Replace with a non-OBDII modem such as the MLT-325o The ability to trouble shoot and verify OBDII operation prior to installing a FMS modem cannot be over-emphasized. Purchasing an inexpensive OBDII device from ScanTool ( ScanTool.net ) such as the ElmScan 5 or equivalent can save hours of troubleshooting.<br><br> This compact and durable tool supports all OBDII protocols, features automatic protocol detection, and ships with a number of compatible diagnostic programs. Conclusion www.fmsgps.com 8