Panic, a little light is burning!
05/09/2026
The British and Americans call them by their name: "idiot lights". Sometimes it really is the case that you feel like one of them when another light comes on in the dashboard. It's particularly funny when the place where it starts to light up was previously just a black area - no warning that something important might be displayed at some point. Of course, when you switch on the ignition, the whole Christmas tree lights up briefly, but who goes through every illuminated symbol and reflects on its possible meaning should you come across it again as a solitaire? It lights up briefly, it goes out - ideally all of it - and that's that. End of point.
But one day it happens: something lights up, a reason to panic! This may be the case with certain cars, for example if the oil pressure is missing, then it probably really is missing and there is every reason to stop and investigate. The same applies if there is a control indicator for the brake fluid level and it is showing, even if only intermittently. Not good!
Recently, however, the "Oxygen Sensor" light came on in my Jaguar. Everything else in the recent past has been a joy to behold and I've put a lot of effort into the car to - as one colleague calls it - "flog it out". 14 years of styling are really not a good idea for a car. But then this light, the sensor: the lambda sensor? A defect! I was afraid that the injection would now do something stupid and make the mixture too rich or too lean. And that I would ruin the engine, the catalytic converter or everything together. So should I carry on driving or call the breakdown service immediately?
A look in the owner's manual only told me that if the light is on, I should change the "unit", i.e. the sensor. Along the lines of: If the engine light is on, please replace it. So: nonsense! However, a little research and reading in various forums brought a lot of reassuring information to light. This light is not connected to the lambda sensor (or rather the two lambda sensors on the V12)! So how does this light know when to start burning? The answer lies in the fact that the odometer is connected to it.
The "Oxygen Sensor" light is therefore basically a maintenance indicator and this is not technically motivated - even Jaguar trusts that their exhaust gas treatment is reasonably maintenance-free - but the light meets a requirement of the American legislator. Although my car is a Canadian version, for example, it has an electric engine heater (unfortunately only for 110 volts), the light is just as much a feature here. It is intended to motivate regular maintenance. Its purpose: to create panic! It lights up every 40,000 miles and is intended to suggest that ignoring it could be expensive. It all sounds a bit absurd, because normal car enthusiasts simply understand that maintenance is due at regular intervals depending on the time or distance driven. That's why nobody needs to scare me! And to threaten me with a defect where there isn't one, I think that's pretty uncool! Worse still, the light in question might not even be able to detect one, let alone indicate one. Sorry mate!
Fortunately, there's a reset button behind the rear trunk panel.
