Hello all, I have a quick question.

My XJ shows service required when I start it up but then goes away. Is that normal? Typically any car I owned with a warning light, the light stays on until service has been preformed. I am having issues with the ambient outside temp sensor. Could this be causing the service message?

 

John, this message comes on once a year or every 12K (?) miles (whichever occurs first). This is a message that most of us live with because it takes an SSD computer to reset. If you go to your dealership to have maintenance done, then it has probably been a year since you have been. I do not believe that the ambient temp sensor would cause the message that you are seeing.

Just for reference, the ambient temp sensor is located in the driver's mirror. So, you may see it high when you first get in (especially if your car is black) and then as you drive, come down to a more realistic temp. if it is bouncing all over the place, then you probably have a loose wire near the door hinge.

 

Some OBDII scanners (not low end, but for instance the Autel CT200 or AP200 which you can find for ca. 40USD) will also allow you to clear that service message.

Contrarily to other cars, on a X351 there is no magic combination of buttons to push to clear that message, or if there is it has not yet been discovered.

 

I'm pretty sure the Service light appears briefly upon startup to inform you that routine service will soon be needed. Age and mileage trip various triggers; engine oil, brake fluid, etc. When the light remains on, some routine service is required. I concur with the comments above regarding code readers and DIY reset.

 

Thanks everyone!