Have a Code? OBD II Trouble Codes Here

[ExplorerDMB]

A normal 16-pin Data-Link Connector​

OBD-II is on some '95 vehicles and most '96-present vehicles. On Board Diagnostics (OBD) has been around for awhile, but hasn't been mandated in any way til vehicle model year 1996. OBD-II vehicles store codes in their computers and must be retrieved with a scanner or a code-reader. A Diagnostic Trouble Code (DTC) is made up of 5 digits. Look below:

There are two types of DTC's -- Type A and Type B:

Type A

Emissions related.
Requests illumination of the MIL after one failed driving cycle.
Stores a freeze frame DTC after one failed driving cycle.



Type B

Emissions related.
Sets a Pending Trouble Code after one failed driving cycle.
Clears a Pending Trouble Code after one successful driving cycle.
Turns on the MIL after two consecutive failed driving cycles.
Stores a freeze frame after two consecutive failed driving cycles.


This is by far the best code description layout I've seen for OBD-II systems (PDF File):

East Coast EFI Codes


The following link is to obd-codes.com which shows Fords Manufacturer Specific codes:

Ford Specific Codes


There are four types of codes, Powertrain (P), Body (B), Network (U), and C (Chassis) The most common is Powertrain.

 

[ExplorerDMB]

bump

 

[ExplorerDMB]

Getting P0171 and P01174

Read this: MAF Bulletin

 

[Ranger379]

do u need to know what those codes mean?

 

[410Fortune]

www.OBD-2.com

Google your code.

 

[ExplorerDMB]

do u need to know what those codes mean?

What do you mean you need to know what they mean? Some Scan tools will tell you automaticly what the code means. But like 410 said, you can get the definition online. Some codes you don't need to look up because you know them by seeing them the most.

-Drew

 

[spindlecone]

Drew
as in the below, a few down posts, are these codes part specific, can one code envolve multiple parts and or systems?

 

[ExplorerDMB]

Drew
as in the below, a few down posts, are these codes part specific, can one code envolve multiple parts and or systems?

Can you explain your question a little more - I think I know where you are going with it, but I just want to be sure?

-Drew

 

[spindlecone]

Can you explain your question a little more - I think I know where you are going with it, but I just want to be sure?

-Drew

What I am saying is say one gets PO171/ 174, in my application that was a vac leak, than others say 02 sensors.
Is the PCV system (where my leak was) tied into the sensor system.
hard to explaine, can one code implicate, more than one part and or system.
I:E P0401 on my engine is almost always the DPFE.
What I am trying to say is, sometimes with codes people start swapping out parts that the codes point to, when it may be another part of the same system, I think codes are system specific, not part specific, than the problem becomes I think, what part in that system is at fault

 

[sparky2263]

A code is an indicator. That's it. When the computer sees a sensor (input) or a controlled item (output) outside what is set for it's normal parameters, it sets a code for the related item. When you read the diagnostic chart (very few bother) it lists what systems the chart is supposed to diagnose.

When a lean or rich O2 sensor code sets, it's generally because the exhaust is rich or lean. And the O2 sensors are seeing that. But, Autozone will sell people O2 sensors because neither them nor the customer understand trouble code diagnostics. I saw them sell a guy 4 O2 sensors when the only problem was a blown O2 heater fuse. Stupid.

Trouble code diagnostics ain't rocket science. It does take a clear understanding of what happened and why though.

 

[spindlecone]

So related items within one system? not item specific?

 

[sparky2263]

A lean exhaust code could be low fuel pressure, vacuum leak, clogged injectors, etc.

It's simply an indicator. Diagnostic charts are formatted as a process of elimination (or cause).

 

[ExplorerDMB]

I have updated the links to "charts" of OBD-II codes. The first link in the origional post is the BEST I've ever seen. It includes from Emission control system codes, to Transmission. If you can't find it on there - You might as well stop looking!

Here it is again (PDF File)

East Coast EFI Codes

-Drew

 

[SoBeLover]

A lean exhaust code could be low fuel pressure, vacuum leak, clogged injectors, etc.

It's simply an indicator. Diagnostic charts are formatted as a process of elimination (or cause).

I had lean exhaust codes pop up after having my Explorer coded due to the CEL light being on plus my gas mileage was lousy......looked in my Haynes to find out what could be the problem. It turned out the IAT sensor was shot

 

[ExplorerDMB]

Added Ford Specific Codes to the links.

-Drew

 

[BrooklynBay]

Here is another site that has a listing of trouble codes for most vehicles: http://www.troublecodes.net/technical

 

[BrooklynBay]

This site has a list of Ford trouble codes: http://www.myscantool.com/dtc/specific/ford.html

 

[BrooklynBay]

This is a PDF manual for Equus which has a list of foreign, and domestic OBD-II codes starting from page 45: http://www.iequus.com/downloads/manuals/3100c.pdf

 

[BrooklynBay]

http://www.equus.com/support/obd2_definitions.php. You type in a code, and it will look it up for you.

 

[BrooklynBay]

This site has a downloadable OBD-II list, and other trouble code information for Ford, GM, and Chrysler: http://www.tradervar.com/instructions.htm