09 35d, CEL light on

[JCL]

All recalls apply to a certain range of serial numbers and vehicle configurations. Just because there is a recall on a 20xx model yy, doesn't necessarily mean all the models built that year.

Mandatory recalls involve safety systems. Parts are either replaced or inspected, depending on the situation, ie if an inspection can determine if they are in fact ok.

Other recalls are often classified as "after failure". The manufacturer may have had a small batch of bad parts or potentially bad parts that they can't narrow down to having been used on a specific serial number vehicle, and it isn't safety related. In that case, as soon as there is an owner complaint or failure, they do the campaign. Owners often think that they should get the new parts automatically, but it is entirely reasonable IMO that if, for example, 100 components missed an inspection step and may be good or bad, and they were used on 100 out of 100,000 vehicles but the manufacturer doesn't know specifically which ones, that they wait to see if the part fails. It is all a judgement on positively impacting owners of failed parts (by catching it in advance) vs negatively impacting a much larger population of owners who won't have any failure. And then there is the cost issue. Sure, the manufacturer can suck it up and give everyone free parts to protect their brand. But we end up paying for that in any case, in price increases.

When a manufacturer decides to do a campaign on a full range of serial numbers (ie before failure) it is because there is a high impact of the failure occurring (ie consequential damage) or it is easy to do (ie at time of scheduled service) or there is a clearly identifiable population of impacted vehicles (ie the cause or failure mode is specific enough that all or most vehicles built in a certain date range with a certain configuration will have the issue)

To all of the above, add in dealer competence. Did the dealer check the VIN, did they do the campaign they should have, and did they do it correctly. Lots of variables.