Can anyone tell me what is this switch by the OBD II Diagnostic Plug on my 2002 Jaguar X-Type (2.5L Gas)?

These pictures were taken under the driver's side dash, near the door hinge.

The check engine light came on this morning, but turned off this evening after I depressed this button. Does it reset the diagnostic computer?

The car runs fine and has ~58K miles. The only unusual behavior this morning was:

1) Atypically cold for Houston, ~32F.

2) A DSC System Fault message also appeared this morning, but that message ceased after I parked the car at the office all day (this happened once before a few months ago when I hit a hard bump on the Interstate, and also ceased after I parked at the office).

Any help is appreciated.

Dyson

 

I don't think that's anything from the factory. The OBD codes are cleared with a code reader.

 

Could this switch by the OBD II be for an after-market alarm system?

I purchased the car used and it has an after-market alarm system which I never use (and don't know anything about).

Thanks.

Dyson

 

definitely an add on of some sort. ejection seat? machine gun? smoke screen? Any of those things happen? Funny that it's a plunger and not a toggle switch? perhaps it arms the aftermarket alarm?

 

Ejector seat?!

Hmmm. I need to test that, but with whom in the passenger seat??!!

Got 3 boys, 2 dogs & the misses.

Hmmmm!!!!

 

The misses !?!?!?

 

Looks like a valet switch for an aftermarket alarm switch, I had one on another car but could never figure out what it was for.

 

exactly what i was thinking.!!!

it is definatelly aftermarket, does it click and hold or is it a pressure switch?
is there plastic that coveres it or is it just there sticking out?
follow the wire and see where it goes to...thats probably your best bet, worst thing that happens is it turns out yur headlight sprayers have been replaced with machine guns...i bet every1 will get out of your way on the highway!

 

I found the same puch-button momentary type switch under MY dash!

I was looking under the dash for the make and model of the remote starter unit that came with our car, a device I had never used, and spied the same switch. The instructions for my remote starter are here:

http://www.directeddealers.com/manua...t/2205a_OG-Eng[1].pdf

I found the description of the button on page 16 of that document.

(The link refuses to paste in here fully, you need to cut and paste it, clicking it will not work)

It is the "Valet Mode" switch, which deactivates the alarm for a period of time.

Poke around under the dash some more, look for the "Black Box" for a remote starter. You just might have one installed and still there, just waiting for a remote fob to operate it.

I tried mine, but immediately generated an "Intermittent Misfire" code because it does indeed start the car, but it does not rev the engine up enuff to let it run smoothly in the winter cold.

I am not impressed by the units operation. Nor am I impressed that the installer mounted the off/on switch in such a manner that I must remove it to plug in the OBD-II reader. Idjuts!)

Hope that helps! "Valet Button" Mystery solved!

 

Do the Misses...or one of the two dogs, just make sure they're wearing a safety hemlet.