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SAE J1930 terminology

SAE J1930 terminology


For model year 1994 and later cars, a partially new terminology for all emission- related components, signals and functions has been introduced. This new terminology, designated SAE J1930, conforms to a standard agreed upon by the automotive industry and government authorities. It has been adopted as Society of Automotive Engineers Recommended Practice.

Local authorities in California (CARB, the California Air Resources Board) require the terms in this J1930 standard to be used in all service literature concerning emission-related systems for model year 1993 and later cars (see Service Manual 2:7 TRIONIC for M93 Saab 9000 as an example) .

For the United States as a whole, the U.S. Environmental Protection Agency (E.P.A.) has proposed that SAE J1930 terminology be required for model year 1994 and later cars.

During a transitional period, the use of this terminology will naturally give rise to a number of problems for all mechanics who have long been accustomed to using the existing terms for Saab components.

However, the intention is that standardization in this field will in the long term reduce confusion and the risk of misinterpretation. To give an example, what Saab calls an AIC valve is called an "Electronic Air Control Valve Solenoid", "Auxiliary Air Control Valve", "Idle Stabilizer Valve" or "Air Control Valve" by other manufacturers.

On model 1994 and later cars we call it an IAC (Idle Air Control) valve, which is also what it will be called by the world's other motor manufacturers.


SAE J1930 terminology has not been arrived at on the basis of the terms used by the majority of motor manufacturers. Instead it has been built up by applying certain rules of logic, according to which one or more attributes are added to a basic term in order to define it more precisely.

Let us once again take " Idle Air Control Valve " as an example:


• The basic term is Valve .

• Control denotes that the valve has a controlling function.

• Air tells us what the valve controls (air).

• Idle , finally, describes the kind of air the valve controls - idle air.

To facilitate the transition to this new terminology, a table of Saab's previous terms and their corresponding J1930 designations is given below. Some of the terms included in the table might not be used in this particular Service Manual, but you will no doubt meet them sooner or later in other connections.

Since SAE J1930 terminology is a local market requirement, the changes in terminology will naturally affect other markets to a lesser degree. In spite of this, we believe it is important for you to know about these changes wherever in the world you happen to work. Even if you have no other use for it, you can consult the following table if and when you come across an unfamiliar term.

The table has been compiled to show the difference between the terms previously used and the new J1930 terminology.

The correct abbreviation is given in brackets ( ).


.

Previous term

New SAE J1930 term

.

Automatic Idle Control

valve, AIC-valve

Idle Air Control valve (IAC valve)

.

Fault Code

Diagnostic Trouble Code (DTC)

.

Temperature sensor

Intake Air Temperature (IAT) sensor

Engine Coolant Temperature (ECT) sensor

.

Test socket

Data Link Connector (DLC)

.

.

Throttle potentiometer

Throttle Position (TP) sensor

.

Td signal

RPM signal

.

Crankshaft Sensor

Crankshaft Position (CKP) sensor

.

.



Camshaft Position Sensor