OBD Diagnostic Codes

Most vehicles generate computer codes used for diagnosing simple and complex problems. These codes help service mechanics more efficiently locate and repair vehicle problems.

1,022 Questions
Car Computers and Sensors
Car Electronics and Lights
OBD Diagnostic Codes

What are the OBD-II pins?

Honda Man'sSince we don't know what make, model or year your car is, this is a difficult question. If it is in fact OBD II, the connector should be located under the driver's side dash.

In order to find your codes, you don't need to plug into the obd2 port. On the bottom right side of the diagnostic port, there should be two pins rather close together. My recommendation is to go to Auto Zone. Some of their stores actually have a key for checking GM obd1 systems. It looks like a key, and has two prongs on it that plug right in to where you need to check your codes. If your local store does not have one, then my advice is to look on the port and find the two bottom prongs that are closest together and jump them.

I have the exact same pinout on my 1995 Buick LeSabre. I have been researching this issue for some time now. The VECI label abve the radiator in my car states "OBD 1 Certified." However, I believe this is only stated because the pinouts of the connector are wrong. I have the VIN L engine, and all technical docs for that engine point to it being controlled by a PCM. PCMs do not report codes by flashing the SES light, only GM ECMs do. GM cars with an ECM and a 16-pin J1850 non-OBD-II connector on them, have a pin-out of 4,5,6,9,12,16. You short pins 5 and 6 to receive diagnostic trouble codes via the Service Engine Soon light. As you can see, those pins do not light up with our common connectors. Our connectors use pins 4,5,8,9,14,16. What I can tell you about this connector is as follows: 4=Chassis Ground, 5=Signal Ground, 8=Keyless RF Trigger (short to 5 to enter program mode), 16=Battery+. (Note 4,5=Ground 16=Battery+ are standard pins for the OBD-II standard. Yet another thing that points to an OBD-II serial uplink.) 1995 was a transition year for GM, in many different aspects including OBD-II. I believe what happened, what the pins were installed in one order believing that they conformed to standard, and then the standard changed before finalization. For more information on this, check out my regular posts to Automotive Forums.com in the Buick LeSabre forum. This is my latest: http://www.automotiveforums.com/vbulletin/showthread.php?t=307153

Transmissions and Drivetrains
Check Engine Light
OBD Diagnostic Codes

What is OBD code P0700?

P0700 is EATX code present.

It simply means that the engine computer has noticed that the transmission computer has a dtc in it. This causes the Pcm (engine computer) to turn the check engine light on. You will need to have the TCM (trans computer) checked for codes to know what to diagnose.
General automatic transmission fault. It could be a sticky internal sensor. A transmission shop could read the actual fault from the transmission.

Dodge Intrepid
OBD Diagnostic Codes

What does a P0174 mean?

Bank 2 running too lean.

Dodge Dakota
OBD Diagnostic Codes

What is Trouble code p 1862?

P1682 Charging System Voltage Too Low

Toyota Sienna
OBD Diagnostic Codes

How do you read the ODBII diagnostic codes for a 2001 Toyota Sienna?

chilton auto repair manual available free at your local public library. vid i have a 2001 Sienna with the check engine light on. had a diagostic machine check and got a code P0171 AND P0174. And it says "system too lean". Also it the diagnostic reads: O2S212 .625 mv O2S211 3.29 mv your info will be greatly appreciated. po 171 is almost always the mass airflow sensor located in the air cleaner box. start with that, its only about 150.00 for the part and is easy to replace. I took MAF off the top of the air filter with two screws and clean it and reset the check engine with ODBII code reader I called Toyota dealer in Canada it cost $245 plus tax

P0171 specifically for Toyota is generic "too lean", and very well could be MAF, but the MAF can be cleaned, recommend trying aerosol cleaner before buying a new one, and run the OBD again to see if it will give you a more specific fault code..it could be O2 sensor, MAP Intake (Manifold Absolute Pressure) and dozens of other things. No dispute here, just adding

you can choose china brand Launch X431 Creader VIII CRP129 from vipprogrammer.com, it is designed to almost vehicle, and read the ODBII diagnostic codes, als have others car diagnosis function, it is an good diy tools for owner, diagnosis and maintenance easier and cost even less. Maintenance and Service All in One, Because it has more application, like Engine Oil Reset, ABS Bleeding, and more.

Ford Windstar
OBD Diagnostic Codes

1999-2003 Windstar has rough idle - has OBD codes P0171 and P0174 and feels like it's ready to stall?


I have just recently started having misfire issues with my 2000 with a 3.8 ltr. I had the dealer that I use run a full computer scan on it. It came back with rear o2 sensor, map sensor, cam position sensor and FUEL INJECTOR 1. Guess what, no exhaust leak.. o2 sensor ok.. mechanic said replace injector 1 and all other codes will go away. I have asked a couple other mechanics and they all say the same thing, bad fuel injectors will reek all kinds of havoc and throw odd codes. If your vehicle is suffering from a rich or lean mixture, make sure you have it scanned at a reputable ford dealer for fuel injector issues, it might just save you a lot of money and they are not hard to change yourself. Oh, by the way, don't buy the injectors from the dealer unless you are going to have them change them. Most dealers charge between 65 and 75 for each injector. I found them at advance and o'rielly's as well as on e-bay for a lot less. Problem solved on my van. Good luck!!

AnswerI just recently became aware of this common problem with 1999-2003 Windstars.

The first, and most persistent indicator that this MIGHTbe a problem is getting P0171 and P0174 scan codes - they indicate a lean condition Bank 1 and Bank 2.

Another symptom is a rough idle - and it may be an intermittent rough idle.

There are other diagnostics cited at both of the linked resources to confirm if your Windstar may be afflicted with the problem.

For reference, there is a TSB (technical service bulletin) officially recognizing the problem and a proposed remedy: TSB# 03-16-1

There's an exhaustive photo guide and discussion regarding this repair via the "Related Links" below.

Be Warned: if you do visit AutomotiveForum.com, as the gentlemen suggests, it's addictive to want to read everythingavailable on the Windstar!

Check PVC grommet in the valve cover. Should be tight around the PVC. Check the Fuel Pressure Regulator Vacuum Line. It has a tendency to swell and leak at the Regulator end.

AnswerI means you need to have your intake manifold gaskets replaced and perhaps the valve cover too. I had this done on my Windstar , here is a link that explains it all.

http://leckemby.net/windstar/windstar01.html (linked below)

I did this myself for less than $80.00 very simple.

Fuel problem:

  • Fuel filter needs replacing
  • Fuel pump is failing - check pressure

Vacuum leak?

Bad gas or Ethanol

This is usually caused by vacuum leaks that the average person cannot fix. It can be repaired by a reputable mechanic for around $850.00 but once it is fixed, it's fixed and you won't have to keep going back again and again for the same codes.

AnswerIt is very possible your Mass Air Flow sensor is sending bad signals to your pcm. They can cause screwy problems sometimes. This should also be throwing a fault code. Is your check engine light comming on? If so have the fault codes ran. If not the only other way I can think of is to hook up the computer to a real time scanner and compare the values of the sensors with the values they should be. You will need access to a factory manual for this though.

it soundslike a misfire or multiple misfire. check the plugs, wires, ignition coil, and the timeing. those are the usual causes, bad head, head gasket, or crank angle position senser have the same simptoms so further probing might save trouble later

I also have a 2000 ford windstar. I replaced or checked the following.

1. Replace Idle air control valve. $80.

2. Fule filter $10.

3. Make sure vacume hoses behind air filter box is connected.\

4. Replace PCV valve. $6

5. Make sure the spark plugs are not over 4 years old.

bad o2 sensor or active fault code it needs to be scaned auto zone does it free

Trouble code P0171 means: Fuel System Too Lean (Cylinder Bank 1)

Trouble code P0174 means: Fuel System Too Lean (Cylinder Bank 2)

More info...These 2 codes are common indicators of a well-known failure on the 1999-2003 Windstars. Be sure to review the additional information in the "Related Questions" below...

I would like the whole list of error code.I have other codes,but my manual don't have this other codes

Remove the negative cable on your battery for about 5 min. It should clear any codes stored in the ECU.

I own 1999 Ford Windstar XL 3.8l engine, and I have same codes P171-P174 it is mean for lean codes of upper bank. Diagnosing the codes gave so much about it. I decided to take it to the dealer and they told me sam code for various problems. Bill to repair is about $1200.00.I did repair by my self and find that lower and upper intake plenum gaskets went bad.After that no codes at all. Repair was done 3 years ago.That is the cure of the problem and cost me 8 hours of my labor and $275.00 in parts.I have around 95000 miles on it .

Chevy Astro
Emissions and Exhaust Systems
Check Engine Light
OBD Diagnostic Codes

What causes OBD code P0420?

This code means that your catalytic converter efficiency has dropped below the nominal value. p0420 is a generic code for the catalyst to indicate that you need to investigate a potential problem with your emissions system associated with the catalytic converter.

Code P0420 means "Catalyst System Efficiency Below Threshold (Bank 1)"

P0420 is actually Catalyst System Efficiency Below Threshold Catalyst System Efficiency Below Threshold.

This means that the secondary O2 sensor detects that the catalytic converter isn't working as efficiently as it should.

This engine code can be triggered by any one of the following:

1.) The catalyst in the catalytic converter is cracked, clogged, or otherwise damaged.

2.) The secondary O2 sensor is malfunctioning.

3.) There is an exhaust leak.

4.) The computer unit is faulty.

Trouble code P0420 means: Catalyst Efficiency Below Normal (Bank 1)
Code PO420 is catalytic converter efficiency low bank 1, sensor1. You did not state as to the year,make and model of the car as well as the engine size. I am a member of IATN and the majority of there fixes was related to someone installing an AFTER MARKET converter. There is a big difference. I strongly suggest that you go to a repair shop with the proper equipment as well as a very good tech to diagnosis the problem. You could replace parts and never fix the problem.jd1709

Serpentine Belts
Ford Taurus
Air Filters and Intake Manifolds
OBD Diagnostic Codes

97 Ford Taurus What does the error code p0420 mean?

Trouble code P0420 means: Catalyst System Efficiency Below Threshold (Bank 1)

Dodge Dakota
Toyota RAV4
Late Model 1979-New Ford Mustangs
OBD Diagnostic Codes

Where is the OBD connection on a 1998 mustang?

== All OBD II equipped vehicles (1996 and newer Mustangs included) have the data link connector, or DLC, located underneath the dashboard, just to the right of the steering wheel. Sit in the car and it's most likely above your right knee.

Car Computers and Sensors
OBD Diagnostic Codes

How do you reset the computer on a VW golf?

To reset the service lights on a Golf III, it's weird. You turn the key on (but do NOT start the engine), hold the odometer button, then turn the key off while still holding the button. Now press the hour button on the clock. This will reset the service reminder for an oil change. If you have an "IN 01", you must do it twice; three times for an "IN 02". If this is the only cause for your Check Engine light, it will go out after a few miles and stay out. To reset de computer to disconeect the battery of the car for 3 hours. Other way is with an scanner machine . The best way is to disconnect battery then hold battery terminals together for 3 seconds. This restores factory fuel and ignition map settings.

Lincoln Continental
OBD Diagnostic Codes

What is 1997 fault code p 1744 description?


The Chilton repair book : P1744 Torque Converter Clutch (TCC) System Mechanically Stuck in Off Position




Honda Accord
Honda Accord EX
OBD Diagnostic Codes

How do you reset a radio error code 1 on a 2001 Honda Accord?

The car comes with a card. It looks White like a credit card and it has your radio's numbers. It should be 5 numbers. Then you disconnect the battery wait about 15 seconds, reconnect the battery and then dial the numbers in your radio's buttons. Mine is 25555 give that a try. If you don't have the card contact a Honda dealer and give them your Vin #. PS. you might have to go to the dealer in person, because of security reasons.or try this
OBD Diagnostic Codes

What's the most probably cause for a code 44O2S lean?

your vehicle may need a new o2 senser, look under you vehicle around the catalytic converter. it looks like a sparkplug screwd into your exaust system with a wire leading to it, pull off the wire and remove carfuly, you may need to heat it up first

Ford Explorer Limited
Classic 1964-1978 Ford Mustangs
Late Model 1979-New Ford Mustangs
OBD Diagnostic Codes

What does the Error code P0316 for Ford Mustang mean?

missfire on star up first 1000 rpm ignition coil is going bad use a ford coil if you dont want a lot of problems with aftermarket units

Car Computers and Sensors
Chrysler 300 Series
OBD Diagnostic Codes

What does P0300 code mean on a Chrysler 300?

P0300 Diagnostic Code - Random Misfire

Engine may stumble or miss
Engine may be hard to start
you may notice no issues

Failing spark plugs or spark plug wires
Bad coil or coil pack
Failing oxygen sensor(s)
Bad fuel injector or more than one
Stuck exhaust valve
Bad catalytic converter
EGR valve or valve passage clogging
Bad camshaft position sensor
Bad PCM or ECM

The Fix
Best first action is a tune up, new plugs, wires, inspect all hoses and wire connections then reset the code. If it returns you will need to narrow it down to a system, coils and coil packs should be tested, catalytic converters for function ( do you smell rotten eggs?). A misfire that jumps cylinders could indicate a lean condition, do you have any other codes along with the 300? this will help clue you in to the source, check valve function to make sure they are opening and closing fully.
This is probably pone of the most difficult codes to troubleshoot, so start with the basics and work your way into the more expensive options, in many cases a good old tune up solves the problem, back it up with a fuel system cleaning and see where you stand.

OBD Diagnostic Codes

How do you reset P0446 Error Code?

pull the battery for a few minutes. if it comes back check gas cap seal or purge solenoid temporary relief

Dashboard Lights and Gauges
Cadillac DeVille
OBD Diagnostic Codes

How do you pull codes off the ECM using ground wire FlashingCheck Eng what are the codes?

Don't know where you are located ,,but,, most of the auto parts supply houses have the codes and readers for free or can be borrowed. Some will even do it for you .AUTO ZONE OR O'RILEYS for example

Volvo S80
OBD Diagnostic Codes

What does code TCM-000C translate into for a 1999 Volvo S-80 T6?

Diagnostic trouble code (DTC) TCM-000C is stored if the control module detects that the vehicle speed and engine speed (RPM) signals do not correspond with the programmed values and that an "incorrect" gear is being used in relation to the calculated gear. This is because solenoid S2 is stuck in open or closed position.

Check Engine Light
Nissan Sentra
OBD Diagnostic Codes

How do you read the diagnostic codes on a 2001 Nissan Sentra?

Take it to Auto Zone and they will read them free.

OBD Diagnostic Codes

Help with error code p4060?

Need to know the following, year, engine liter size, model.

Check Engine Light
Ford Bronco
OBD Diagnostic Codes

What does the check engine light error code P01400 mean on a 1996 Ford Bronco?

did you mean code P0140 ? this means o2 sensor no activity( bank 1 sensor 2) in other words replace the O2 sensor. hope this answers your question.

Hyundai Sonata
OBD Diagnostic Codes

Where can you find diagnostic codes for 2 liter 1997 Hyundai Sonata?

take your vehicle to auto zone they have a free service to hook up to your vehicles computer and read out computer codes they will then tell u what the codes mean it works i just did it on my 98

OBD Diagnostic Codes

What does a obd code 14 mean?

what car??

find your car on this site and i am sure you will find the code. http://www.troublecodes.net

Auto Parts and Repairs
Dodge Dakota
Toyota RAV4
OBD Diagnostic Codes

Where is the OBD connection on a 95 Maxima and does it have an OBD1 or OBD2?

The OBD connector is located under the center console on the passenger side. It is OBD-II although not fully compliant.

Chrysler PT Cruiser
OBD Diagnostic Codes

How do you fix code p1776 on a Chrysler PT Cruiser?

P1776 how do I fix


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