OBD1 Vehicles Check Engine Light Codes

In the early 1980s, domestic and imported vehicles began to be equipped with computers known as electronic control module (ECM) to control the engine emission system. This was in response to a mandated law by the US Federal government "Clean Air Act of 1970" to control air pollution. With the advent of rampant smog pollution in California in 1985, the estate enacted the California Air Resources Board (CARB) which created the On-Board Diagnostic (OBD1) system.

The OBD1 system main purpose were namely: to warn vehicle owners during engine emission failures; help technicians diagnose the emission problems and identify the culprits that could raise exhaust emission levels from vehicles. The basic procedure uses a pin or a jumper wire which is connected to a diagnostic connector. Fault codes were taken from control units memory using a series of voltage flashes to indicate a particular check engine light code. The flashing light could be seen in the vehicle dash panel or box specified by the vehicle maker. When utilized, this light code will point to a defective circuit, sensor or service required by the vehicle. Aside from cars, these first generation OBDI system was also applied to new light duty trucks starting 1988 upto 1995-96.

A fault code will direct the mechanic to the defective malfunction circuit. This malfunction will be stored in the computer memory for a period of time or during a set of engine start and run cycles. OBDI was a good step forward in helping technicians but was limited because they did not cover all emission control system components. In addition, the OBDI regulations did not provide proper regulations for manufacturers to standardize their computer systems. As a result, Gm, Ford, Dodge vehicles have the Throttle Body Injection (TBI) and Electronic Fuel Injector System (EFI) systems which were started in 1982. Then Asian vehicles counterparts followed suit a year later although European vehicles were more ahead in their implementations which dates back to 1981.

Check engine light codes for OBD1

Before you buy an OBD1 scanner, browse thru some of these links on left so you can get the fault by jumping the diagnostic wire connectors.

Check engine light code analysis

When diagnosing the check engine light codes, emission components are monitored for wiring continuity, shorts, and in some cases mechanical functions such as those used on advance European models. OBD1 systems were normally limited to the detection of an open or short in a sensor or wiring circuit. When a check engine light code occurs, the light remains illuminated as long as the fault is detected and goes away once normal conditions return. This fault code information remains stored in the computer long term memory regardless of whether a permanent hard fault or intermittent fault caused the code to set. Also, OBD1 vehicles store a fault code in the computer long term memory until power is removed from the computer like disconnecting the battery or removing the fuse.

Most of the techniques in getting the OBD1 check engine light codes are shown in this website in detail. If you click on the right navigation links, you will access most of them including check engine light reset tips and brief descriptions on check engine light causes. OBD1 was designed on vehicles equipped with electronic fuel injection so you can generally retrieve the codes yourself. There is no need to buy a scanner or going to any parts stores to have your vehicle scanned for codes. All you need is a complete description of the fault code which are mostly available in the Internet.

Fixing check engine light codes

Knowing your OBD1 fault code and fixing it will need 2 important tools after you get the description. They are common fixes database and the vehicle wiring diagrams. The former is a list of fixes for every possible symptoms associated with the fault code. It will describe the usual electronic components and wiring involved in the fault code. It is based on the design of the vehicle and history of repairs performed on the type of vehicle being worked on. The latter tool is used if the problem needs a closer look that involves a complete wiring circuit description which is shown in the diagram. This includes the location of the components, the color of the wires and the related parts like switches and relays associated with the fault code. Feel free to check out this website so we can help you fix your check engine light codes.

As soon as you get the code fault number, check out the OBD1 and OBD2 sample fixes on this blog link below:

Click Here for free " check engine light codes" fixes

On the link above, you will have a glimpse on how it is done using the common fixes. What symptoms to look for because all of these are needed together when fixing your vehicle problem. And to be really effective in fixing the engine light problems, you also need a wiring diagram. This way, you have a guide when testing the defective components or wires.

A lot of folks are making the mistake of knowing the common fix and check engine light code only. You also need to test the wires or components to make sure what engine system is involved. This is where a wiring diagram can really help you to get the best result. This proven system means no guessing or replacing of parts until you are sure.

Please try to remember:

OBD1 means you can get away with no scanner if you know which wire or connector to get the code. After you get the code, find out the common fix and a lot of simple vehicle fixes are done this way. You need a wiring diagram to fix difficult re-occurring check engine light problems.

OBD2 means almost always using a scanner so you can find the code. Most vehicles made after 1996 do not provide the "jumper wire at the connector features" that were available in OBD1.You also need a common fix to verify the code for easy problems but a wiring diagram is the BEST TOOL if the problem is hard to find.

Additional tips when fixing OBD1 or OBD2 fault codes:

1.) Reset the code after getting it erased from the engine computer's memory. On most OBD1 applications, it is safe to remove the battery to reset the code. On OBD2 codes, you need a scanner to be able to do it.

2.) Go for a road test to verify the code. If the same code comes back, make a note of it because that is the one you have to fix.

3.) Do the above procedures after replacing any defective part. As a matter of fact, always do this for every fix you make. Don't proceed to the next repair until you verified your earlier fix. This will prevent replacing unwanted parts and wasting your time.

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Feel free to check this website regularly (bookmark it now) so you can get the latest updates for any OBD1 or OBD2 free check engine light tips.

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