Printer-friendly version
Glossary of terms you will come across during your Phase 2 training.

Browse the glossary using this index

Special | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O
P | Q | R | S | T | U | V | W | X | Y | Z | ALL

Page:  1  2  (Next)



OBD pinoutThe SAE J1850 bus is used for diagnostics and data sharing applications in vehicles.

The J1850 interface takes two forms:

  1. A 41.6 Kbps Pulse Width Modulated (PWM) two wire differential approach, used by Ford. The connector will have contacts in pins 2, 4, 5, and 10, with no contact in pin 16.
  2. A 10.4 Kbps Variable Pulse Width (VPW) single wire approach, used by GM. The connector will have contacts in pins 2, 4, 5, and 16, with no contact in pin 10.
    The single wire approach may have a bus length up to 35 meters (with 32 nodes).

The J1850 interface was developed in 1994, and may be phased out for new designs. The J1850 is a class B protocol.


The document J1930 standardizes the electrical/electronic systems and diagnostic terms, definitions, abbreviations, and acronyms.

It also provides a method for vehicle manufacturers to use when constructing new terms for new components and systems.

The J1930 document focuses on diagnostic terms applied to electrical and electronic systems. It also contains the related mechanical terms, definitions, abbreviations and acronyms.


The SAE J1939 Standards Collection

SAE's J1939 standards family is the preferred controller area network (CAN) for equipment used in industries ranging from agriculture, construction, and fire/rescue to forestry, materials handling, and on- and off-highway.

Why Use J1939 Standards?

The J1939 standards family is maintained to ensure CAN device interoperability. J1939, the top-level document in the collection, is the master control for definitions common to many applications and industries, while companion documents explain component rationalization and product standardization for a particular application or industry. Communication systems designed according to J1939 standards are EMI/RFI tolerant, free of connection wires, easy to install, and feature log, record, remote access, and self-diagnosis capabilities.

Advantages of J1939 Datalink:

  • Uses less wiring
  • Lower weight
  • Lower cost 
  • Fewer connections 
  • Increased reliability 
  • Easier to install 
  • Improved quality of signal
  • Can transfer large amounts of data

OBDII pinoutThe standard laid out for the OBDII connector.

  1. Manufacturer discretion. GM: J2411 GMLAN/SWC/Single-Wire CAN.
  2. Bus positive Line of SAE-J1850 PWM and SAE-1850 VPW
  3. Ford DCL(+) Argentina, Brazil (pre OBD-II) 1997-2000, Usa, Europe, etc.
  4. Chassis ground
  5. Signal ground
  6. CAN high (ISO 15765-4 and SAE-J2284)
  7. K line of ISO 9141-2 and ISO 14230-4
  8. -
  9. -
  10. Bus negative Line of SAE-J1850 PWM only (not SAE-1850 VPW)
  11. Ford DCL(-) Argentina, Brazil (pre OBD-II) 1997-2000, Usa, Europe, etc.
  12. -
  13. -
  14. CAN low (ISO 15765-4 and SAE-J2284)
  15. L line of ISO 9141-2 and ISO 14230-4
  16. Battery voltage
From the Society of Automotive Engineers, SAE, J2284 defines the specific version of the CAN bus used on the OBD II connector on a vehicle.

From Wikipedia:

James Clerk MaxwellJames Clerk Maxwell (13 June 1831 – 5 November 1879) was a Scottish scientist in the field of mathematical physics. His most notable achievement was to formulate the classical theory of electromagnetic radiation, bringing together for the first time electricity, magnetism, and light as manifestations of the same phenomenon. Maxwell's equations for electromagnetism have been called the "second great unification in physics" after the first one realised by Isaac Newton.

With the publication of A Dynamical Theory of the Electromagnetic Field in 1865, Maxwell demonstrated that electric and magnetic fields travel through space as waves moving at the speed of light. Maxwell proposed that light is an undulation in the same medium that is the cause of electric and magnetic phenomena. The unification of light and electrical phenomena led to the prediction of the existence of radio waves.


Jim McAdam LogoIsola House, Ballymount Road Upper, Dublin 24.

From their website:

With 40 years of experience in the industry, Jim Macadam Equipment Ltd has grown to become one of the largest importer / exporter of construction and quarry equipment in Ireland.

We supply new and used Tracked  Excavators , Mini Excavators , Wheeled Excavators , Wheel Loaders , Backhoe Loaders , Skid Steer loaders , Telescopic Forklifts , Dozers and Dumpers with a emphasis on quality

Operating from a prime location close to the Red Cow and the M50 motorway in Dublin, ( Junction 10 off M50, see map) our firm is well known and respected for the quality of its distributorships.

Jim Macadam Equipment are the CASE, AUSA and Messersi Distributor for the Republic of Ireland. It has achieved excellence over the years for its five star quality and speed of service and parts backup


Company Contact: Mark O'Donovan



Company contact for Roadstone Wood Ltd.


  • Landline: 01 404 1200



Company contact for Pat O'Donnell and Company Ltd.

Telephone: 01 6161 000



Japanese Industrial Standard.

Check here and/or here for more information.


Page:  1  2  (Next)

Please note, if you want to contact the main Training Centre in Baldoyle, you need to ring 01-8167400.

If you want to contact the CP Fitters' Section, you can Contact Us by email,, or by telephone: 00 353 1 8167543 This number gets you through to the CP Fitters' Section, Baldoyle Satellite Unit.

Our Address is : Construction Plant Fitters' Section, Unit 116, Grange Way, Baldoyle Industrial Estate, Baldoyle, Dublin D13 CA48.
We operate in a satellite unit which is about 300 metres away from the main training centre. You can see the location of this unit here, in Google Maps. You can also Check here for directions to the Baldoyle Training Centre.

Find Us on Find us on YoutubeFollow cpfitters on Twitter

Is Féidir Linn! You can view all the menus on this site as Gaeilge by going to the homepage, top right hand corner, and dropping down the language selection menu. By default it reads English (en), so just select Gaeilge (ge) instead.