How does the "annual inspection" service indicator work?

[DaveVoorhis]

A couple of days ago, the "Inspection" indicator lit up on the dash, with the little clock icon beside it. No worries there -- my maintenance schedule is more rigorous than BMW's, but I have some curiosities. According to the manual, that means an annual inspection is due. However, three green LEDs are still lit in the "impending doom" bar graph.

Therefore, my questions are these:

1. Is it normal for the annual inspection warning (or the "oil service" or "inspection" warning) to appear before the bar graph runs out of green LEDs and shows only yellow?

2. How does the ECM or instrument cluster determine when an annual service is due? It has been about a year since I bought the car, but obviously there's no way the car knows that, and the battery was disconnected from late April until August, so I assume it isn't a simple timer.

[Jon K]

I think it just goes based on how much the car is driven at what RPM and such. It can be reset by grounding a pin in the diagnotic connector - no special tools needed.

[DaveVoorhis]

I think it just goes based on how much the car is driven at what RPM and such. It can be reset by grounding a pin in the diagnotic connector - no special tools needed.

Yup. That requires grounding pin seven on the diagnostic connector. I'm familiar with that, and I can see how the "Oil Service" and "Inspection" indicators would be based on RPM and whatnot. What I can't see is how the car would know to pop up an "Annual Inspection" indicator -- which, I presume, pops up once a year -- without keeping track of the date.

[Jon K]

not sure its an actual year ding... some states only have every 2 years, etc etc. I guess it just bases it 365 days from last service reset probably.


Easy way to check would be to set the date 1/1/2006 reset the service fully, then set it to 12/31/07 and see if it tells you it's time.

[cschollum]

how would that work if you dont have an OBC though? cars without and OBC still have the service interval system, however with no obc you have no way of setting the time and date....

My guess it works on its own internal clock, and counts each day since it was last reset???

[Jon K]

True -

Every computer must have its own internal clock - it probably just shoot for like 350 days or so. It's not that weird for it to count down from 365

[Paul in NZ]

th annual inspecton is just that...every year,but i think it goes one year from the reset...Is there a specific reset for the annual inspection as opossed to the oil or inspetion sevice?