I feel like an idiot having to ask this, but am I correct in assuming the up and down function of the lumbar adjustment is to move the lumbar adjustment up or down the backrest, and then increase it as needed? Any time i push up or down, it just seems like it decreases the support, and if i increase it again, it feels like its in the same spot. I resorted to the owners manual, but it just basically said "yup, thats the lumbar support".

I searched and came up with nothing, which makes me believe i am being a bit thick about this.

Thanks!

 

Yes, the up and down is supposed to move it up and down as described with the 4 way adjustment. There is a 2 way adjustment offered, but that would only have fore/aft buttons and not the 4 way switch). It does this by deflating a lower air bladder cell and inflating a higher one via a solenoid block. It is not quick - it takes maybe 10 seconds to fully switch. In the attached drawing of the entire seats it is either 3 (with massage and squabs), 4 (with squabs) or 5 (standard).

The massage bladders have five separate cells, 4 way has two, and 2 way just a single cell.

Assuming the pump is functioning ok you may have a leaky upper cell or maybe a hose at the solenoid is not sealing correctly. The bladder drawing below shows the 4 way and you can see the solenoid, the three hoses (one from the pump, one from each cell) and the deflate vent. Those clips at the solenoid can allow a slight leak. Rub a bit of washing of liquid over them and operate the pump to see if any bubbles form. (If you have squab bladders you will have an extra solenoid on the other side.)

PDF of the lumbar diagnostics attached for reference.

 

Thanks so much xdave, that was extremely helpful. Im sure the issue is that I am not giving it enough time. I thought once you set the amount, then you could move that amount up or down (i think thats how my CLS worked) but this makes a lot of sense.

Thanks!

 

Could the leaky solenoid or hose effect both seats? The lumbar support on the passenger seat operates in the same way as the drivers. Maybe i am just expecting it to do something it cant, but pressing up or down just simply deflates the lumbar in the same spot it inflated.

That being said, the massage works fine, but i dont know if that matters at all.

Thanks for the help.

 

Each seat has its own pump and solenoid block. It's not impossible that both would be leaky, but they would not be linked.

Do you have a four way switch for the lumbar adjustment (like the direction pad on a games console)? If you look up your vehicle spec sheet on https://topix.jaguar.jlrext.com/topix/vehicle/index you can see what spec seats were fitted at the factory. Alternatively if you post a photo of your seat switch pack we can tell from that.

 

It definitely is the 4 way switch. Here is a picture of the passenger side.

That being said, i messed with it while i was getting the picture, and the upper and lower portion of the seat back does seem to inflate and deflate, just not nearly as much as the middle area. Maybe its just how I am sitting?