I went to look at an '04 XJ8 at your typical Main Street used car dealer. The car was very clean and the interior was just beautiful. The car started and idled fine. Took it out for a test drive and it felt great, lively, tight steering, good ride with quiet suspension. While we were out and stopped at a signal light we heard a beeping sound. it was a series of four rapid, distinct beeps. Beep, beep, beep, beep. This happened on two occasions. There wasn't any warning lights activated in the odometer readout the speedo or tach dial, or on the nav screen. The car did not feel or run different.after this.. When we returned to the dealer my Wife looked through the owner's manual and found the section on audible warnings. The manual described the typical ignition key, door open, turn signal click etc. It listed a four beep sequence as being an air bag problem. The air bag icon in the speedo lit and then went out after starting the car which appears to be normal. We did this several times. My old X300 has flashed an air bag warning and air bag read out before, but there wasn't any audible alert.

The car has 123,000 miles and is equipped with parking sensors. Does anyone know what could cause this sound? Thanks.
Yes, I'm thinking of replacing my X300.

 

If you have front sensors as well as rear you may have been to close to the vehicle in front of you.

 

Thanks for the suggestion. At the time I was the first vehicle in line at the red light. The car behind me was at least four feet behind me. Did some searching on the forum and found that moisture leaking into the sensor itself had caused some problems. The car had just been washed at the lot. What concerns me is that the owner's manual states that the series of four beeps indicates an air bag fault. I didn't see any indicators on the dash of an airbag fault, but that didn't make me feel confident about the condition of the car. I wasn't planning on buying a car and then have to take it to the Jaguar dealer for an evaluation. I really liked the car, the interior has all the wood that I love and the exterior still looks like a real Jag. I'll just look for another car that doesn't have this issue.

 

Could certainly be the parking sensors. If you have front and rear on the car (some have just the rear sensors) pull up slowly to a car in front of you they will trigger. Not sure why you would get just four beeps unless the space was then increased by the person in front rolling up a bit. That's the only scenario that makes sense to me. If it should happen again, look at the overhead console and see if the red led lights or blinks. I am not sure regarding the air bag error - I would assume it would be accompanied by a dash warning and/or lighting the airbag light.

 

Vehicle close along side of you will trigger the sensors as well,

 

Thanks to all you took the time to send me an answer.

 

Park assist sensors can be randomly triggered by nearby trucks or busses releasing air pressure or from other random electrical noise that they emit. Other possible causes is sand or other dirt on the face of one or more of the sensors, or even a weak battery. I suspect it was a result of these various false positives that for the X351's, the driver has to enable front park assist every time they need it. I've had my 04 since new, and happily deal with the occasional false positives for the benefit of it being ready to assist when needed.

 

Thanks. All this info is something I will keep in mind as I look into other XJ8s.