What Problems Can OBD2 Scanner Find and Fix?

What Problems Can OBD2 Scanner Find and Fix?

ODB2 scanner is an abbreviation for On Board Diagnostics Scanner.

An OBD2 Scanner can read trouble codes that trigger the check engine light (MIL).

OBD2 scanner tools are the latest industry standard and is incredibly more versatile than its predecessor.

In 1988 the Society of Automotive Engineers (SAE) set a universal connector plug and a universal set of test signals / trouble codes.

Unlike a basic scanner, the OBD2 scanner has a greater ability to define trouble codes and provide more accurate diagnosis, along with being able to tune or tweak performance.

In 1996 the OBD2 scanner was implemented and became the industry standard in USA. Other countries soon followed.

ODB2 Scanner Basics

An ODB2 Scanner can detect many inconsistencies that are present in a vehicle.

It read trouble codes produced by the it’s onboard computer system.

The on board computer system monitors cars emissions, performance, and numerous other functions.

Those codes with trigger and illuminate the check engine light; letting the owner know something is wrong and needs to checked out.

The codes produced are 5 characters long.

Below is the break down of what each character or digit represents…

First character represents the system related to the problem.

  • B = Body
  • C = Chassis
  • P = Powertrain
  • U = Undefined

The second digit lets you know whether the code is generic or enhanced

  • 0 meaning generic
  • 1 meaning enhanced

The third digit identifies the sub system that the code pertains to.

  • 1 = Emission Management (air or fuel)
  • 2 = Injector Circuit (air or fuel)
  • 3 = Misfire or Ignition
  • 4 = Emission Control
  • 5 = Idle Control & Vehicle Speed
  • 6 = Output Circuit & Computer
  • 7 = Transmission
  • 8 = Transmission
  • 9 = SAE Reserved
  • 0 = SAE Reserved

The forth and fifth digits are variable and related to precise problems.

Real Life Example of a Trouble Code Situation

We will use the code P0171 as an example. This code in particular means “System Too Lean” (Bank 1)”.

Possible explanations for this code vary and could mean one or more of the following…

  • Faulty or stuck open PCV valve Failed or faulty oxygen sensor (sensor 1, bank 1)
  • The MAF (Mass Air Flow) Sensor is dirty or faulty

    Note: There is an issue in some vehicles, the MAF sensors leak the silicone potting material used to encase the circuitry. Using “oiled” air filters may cause the MAF to become ineffective if the filter is over-saturated.
  • Possible cracked PCV line or vacuum /connection
  • There could be a vacuum leak downstream of the MAF sensor
  • Plugged or failed/ sticking fuel injector
  • Low fuel pressure (dirty fuel filter/ possible plugged!)
  • Exhaust leak between the first oxygen sensor and engine

Professional Advice Suggested

As you can see just having the code won’t fix the actual physical problem if you aren’t familiar with auto repair.

OBD2 Scanners are very helping with diagnosing a variety of problems.

It can also allow you to perform performance tuning. It is a great multi use tool that is imperative to any good auto repair shop.

If you have any questions feel free to comment below…

What Problems Can OBD2 Scanner Find and Fix?
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11 Responses to What Problems Can OBD2 Scanner Find and Fix?

  1. It appears American English is not your first language. You may want to have someone check your grammar before posting. Just a thought and it doesn’t in any way take away from you great knowledge of cars and these products.

  2. My battery (Just purchased another one) shows low voltage & won’t start if it is left unused after several days. I pulled both radio & Amp fuses but it still shows a current draw. I also disconnected the alternator wire, (But still have the same problem). I checked & there are no lights staying on. Some sites say that either the radio or the dash assembly are defective. This is a 2004 GMC 2500 with 94,000 miles that I recently purchased privately, Otherwise it’s in great running (And looking)shape.
    PS: I am a 71 year OLD retired mechanic.

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