Diagnostic Codes: Tech Diagnostics vs. Self Diagnostics
You have probably heard of the term “pulling codes”, or “reading codes”. The codes are initiated by your BMW or MINI by it’s very own “self diagnostics”.
There is a fallacy out there in the general public; that all a tech has to do is to “plug something into” your BMW or MINI and that a computer will easily tell the tech what is wrong. Part of this misconception may be from the tons of commercials from big box automotive places advertising their pulling codes for free, with some guy holding the little scan tool and making it look simple and easy. But, let’s look at the bigger picture.
For example; OK, so your ABS light is on. Yeah, you will have code that shows it’s an ABS fault. But, you don’t want to replace the entire ABS control unit, if the unit is fine and it’s a problem is a wheel speed sensor! First of all, even replacing the ABS control unit won’t make that light turn off if the RELATED problem is not repaired! There are about a dozen things to check and test prior to even beginning to ascertain that you need the BMW or MINI ABS control unit. (Thats where the real diagnostics comes in) Codes, trouble codes, fault codes, errors, whatever you call them are a product of the the “self” diagnostics of your BMW or MINI. In the ABS, each time you cycle your ignition, your ABS control unit is doing a self check and reporting the findings. Problem = the light!
Other control units and sensors are checked and monitored through a drive cycle. Self diagnosis by your BMW or MINI is awesome. But, it’s a long way away from being the complete answer in most cases. That is why you need a trusted, trained and educated BMW or MINI specific place to retrieve the codes and then get to the root of the issue.