I am curious if there are "electronic switches" that are built into the car that are not written into the owner's manual. Some of the things that I am used to is like with the X-Type, if you press and hold the TRIP button (on the end of the turn signal stalk) and then start the car, you can put the instrument cluster into a diagnostic mode and this will allow you to read some codes (albeit you have to decode them). Another would be like what the wife's Fusion has where you can buckle and unbuckle the front seats a certain way and it will de-activate the seat belt minder unless the person performs the procedure a second time to re-activate the belt minder.

This came to mind seeing another post where someone was asking the process by which to reboot the computers in the car. So, what are some of the "tricks" that are out there. I would be interested in hearing them.

This isn't so much for things like the "DRL relay mod" or other items where you are having to cut wiring and install new stuff. This is meant more for what I call electronic switches that allow a tech in the garage to access something or to disable/enable a feature of the car. Yes I know there are items like this that can be reached via the instrument cluster. But I am pretty sure that there are more than what can be accessed that way.

 

The seatbelt warning chime process that works on the X-Type (and other Jag models) should work on the X351 as well. Try it & see.

 

Cambo, tried the belt mind turn off procedure on the XJ as it is stated for the X-Type. For the X-Type, you are supposed to turn on the car to the RUN position with the engine off. You then buckle the seat, let the belt light clear, unbuckle the seat and let the light return, then buckle/unbuckle the seat 8 more times till you get a chime to sound on the unbuckling. With my XJ, I don't even get the belt minder indication with the car in the "RUN" condition (ie, START button depressed to turn on the instrument cluster, but not stepping on the brake to allow the engine to start). I am going to try it again with the engine running to see if that changes anything. Reading the owners manual, it has a generic statement about turning off the belt minder can be done by the dealership and to take it in. I wonder when I get my Mongoose cable/SDD program if I will have that ability then?

Since we are on the subject of the belt minder, I noticed an oddity with my car. If I have someone in the front passenger seat and they are not belted in, the car will constantly flash me indications that the person is in the seat and not in the seat as the vehicle passes through 3 mph (5 kph?). What I mean by this is as I am coming to a stop, the right side of the instrument cluster will tell me that I am the only one in the car. Then as I take off, the right side of the instrument cluster will tell me that the passenger is now in the seat and not buckled in. This causes the belt minder to go off constantly when in stop and go traffic.

 

With some playing, I have figured out the belt minder. It is slightly different than what a lot of other Jaguars use. So, here it goes. Of note, this can only be done after the car has been turned off, this cannot be done say after a bit of driving.

1) unlock the car and get into the driver's seat and put on the seatbelt
2) start the engine by pushing the START button and having your foot on the brake
3) leaving your foot on the brake, place the car in DRIVE
4) with your foot still on the brake, wait for the right side of the instrument cluster to show the "green" driver (ie, buckled) symbol
5) with your foot still on the brake, unbuckle/buckle the seat so you do 9 unbuckles and 8 buckles. Ensure that the right side of the instrument cluster shows the appropriate condition before doing the next buckle/unbuckle. On the 9th unbuckle, you should hear a chime sound. This is telling you that the belt minder has been turned off.

Please keep in mind that you need to do this fairly quick. In the past, all this buckling/unbuckling (step 5 above) needed to be done in 60 seconds for the belt minder to change state. I haven't tested to see how long your truely have, but I would venture to guess this is still true.

You can use the same technique to activate the belt minder. But, in this case, you will not see the status of the seat belt. So, you will need to add a second pause between each buckle/unbuckle. You also will not get a chime indicating that the belt minder has been re-enabled. You will note that the belt minder light in the lower left corner will come on.

 

There may be a similar dash feature but the codes are usually ANCIENT and NO LONGER APPLY. Ignore them. Use an OBD tool.

 

JagV8, I agree that when looking at OBD codes that a code reader is the way to go. But, like the belt minder feature is not something that you can turn on/off with the code reader. It is these sorts of "features" that I am interested in. Sometimes there are some useful things that can be only accessed this way unless you buy the $1000+ OEM level machines.

 

Sure, no worries, but the codes have misled people e.g. on S-Type forum - with pain resulting. They can't even be cleared by a normal tool so they are almost guaranteed to be ancient.