My Code Reader doesn't do anything - FAQ's

Now, BEFORE you go ahead and smash the "thing" to pieces and shatter your nerves (and someone else's...) let me make something very clear.

No matter what your salesman told you, no code reader will "read" all vehicles! If you are on the market for such thing, hang on little longer because it simply doesn't exist yet. In most cases, if you "work on all cars" then you'll need more than 3 different code readers. Please understand that the code reader is nothing more than a communication link between the car PCM/ECU and you. In other words it translates to you the PCM's language and vise versa. It does this thanks to the software written in to it by other people.

The biggest fault with code readers are actually the vehicle manufacturers, who could not agree (again) to one standard protocol and standard fault codes for everybody. Oh, no, no, no, we Germans know cars better than the Japanese...(or something like that). I mean what is wrong with sticking to one standard? You could go from country to country and get your car fixed! We have been "sticking" to Windows for so long now because it's standard and it works (more or less) and everybody knows how to use it. Anyway, let me get back to code reading...

Code Reader not connecting to ECU:       (Please don't assume! It's the worst mistake you can do! Check it!)

Is the code reader powered? (some derive power from the diagnostic plug, so check for power there first...)

Is the Ignition Switch ON? (some ECU's won't communicate if the key is in off position.)

Is the harness from the diagnostic plug to the ECU ok? ( not damaged by anyone?)

Is this the correct ECU for this vehicle? (you may be trying to connect to something that is not there...)

Code Reader Connecting to ECU but will not "read it" properly:   

Have you connected the correct adaptor for this vehicle? (different adaptors use different connecting pins even if they look the same)

Have you chosen the correct vehicle version in the code reader software? (usually if you make a mistake here no harm is done, but there won't be communication either) (which buy the way leads to one more thought,- try with another model from the same manufacturer)

Do you know what are you trying to connect to?   i.e. If you are not successful connecting to a Jaguar AT gearbox, try Ford (they use the same ZF gearboxes, so there is a chance that the ECU may be "borrowed" too.

In South Africa particularly, we are getting all sorts of "mixes and matches". To the point that even the software for the ECU's is altered from the "standard ones". (i.e. Take Opel for example, in Europe it's perfectly "readable", here not so...)

Don't get fooled by the vehicle year model either! If your Code Reader is imported (and probably is) then it's software will be written for it's main market ( i.e. Europe or America) so a new Toyota here may be a 2-years old model in Europe with different market name!

Worst yet, because we don't have strong (if any) emission-pollution laws in South Africa the vehicle importers are not necessarily importing OBDII or EOBD compliant vehicles. This means that a car may have a OBDII diagnostic socket (and even harness) but the ECU's software is not OBDII compliant. (Why fit an O2 sensor if no one checks if you have one?)( No O2 sensor means you have to load different software in the ECU so it can complete the "close loop" without it.)

Now, OBDII & EOBD is ONLY ( and I will repeat this again - ONLY) about POLLUTION CONTROL. No one cares in Europe if you have faulty Air-Con as long as this fault does not increase you pollution levels. So, anything related to Emission Control and Pollution (codes starting with 0) is in the OBDII standard (generic) codes, which all manufacturers (exporting in those regions of the world) have to comply with. Anything a side from this standard is considered "specific" OEM (codes starting with 1) AND is NOT necessary to implement.

This is why an EOBD/OBDII ONLY code reader costs so little. (Because it does so little...)

Here comes the big "confusion": Because everybody is left in the manufacturers hands, they can change the fault codes meaning as they wish whenever they want. So a Ford specific code: P1500 means "Vehicle Speed Sensor Intermittent fault", but the same code P1500 from BMW means: "Idle Speed Control Valve Stuck Open". Do you see now what I mean with "the big confusion"? It goes without saying that the manufacturers keep their "specific" diagnostic codes secret so we all "hail to the king" and think that they perform some kind of voodoo magic...

Now, imagine you have to write the software for a code reader that have to communicate (properly) with ALL vehicle models on gods earth... You are just bound to get it wrong... One way is to buy the proper code descriptions from the manufacturer. (In doing so, don't forget that they still have the right to change them at any time...) This is expensive and hence some code readers have "ridiculous" prices at first glance! However, those are the ones that will "work" most of the times and give you proper fault code descriptions. Imagine if you swap the two codes will be trying to fix the VSS on the BMW when the ISCV is the real fault! Go explain this to your customers after you've fitted new VSS...

The other method to write the code reader software is to go through very lengthy and tedious process and figure out what sets the code. This method is very slow and you'll need to go thru a lot of car models. There is a third method too...(it involves industry spies and it's not recommended ;-))  The last two methods perhaps are the ones that bring us the "cheaper" code readers...but never forget that you'll still get only what you paid for!

Code readers should have their software updated, as vehicle manufacturers release new models so do the code reader manufacturers. Check with your supplier for an updated software version for your unit.

 So, to sum up all this mess: If your code reader doesn't want to "read" check the power, physical connections, vehicle model and equipped systems. Also try to establish whether or not the code reader is actually capable or "doing" what you want it to do. After that, feel free to whack it in to the wall...(just kidding:-))  Better try the same car with another code reader...

Also, read this material.

Automotive Equipment - in tune with the Future

Crypton Diagnostic Equipment - Automotive Diagnostic Workshop Equipment as used by Dealers and Garages

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