FYI -I down loaded the schematic and found that the second connector color code is blue -orange.

 

Hi MC

I will be installing a sat radio in my XKR after I get some of the other small stuff done. Let me know how you made out with the install and if you ran into any problems.

wcnesta

 

Good news, and good info. I did get my install done with no problems. Not hard, but very time consuming to remove seats, console, panels, etc.. I did a complete write up in this forum just a couple weeks ago. I installed a Starmate8 which I like very much. Only complaints I have is the buttons for the presets are small, and it does not have a remote. Running the antenna wire is the hardest part. Look for the older post. Mark

 

I think I have the same problem with my 2004 XJR. The previous owner was smaller and ligher so the hall effect switch is probably acting different. can you describe the hall effect switch and the connectors that I should be cleaning. location? number of wires etc. There are probably 8 connectors under the seat and I don't want to risk damaging good connections. Are these connectors 4 pin or more, color??

Also the connector on the side is that the one for the side airbag module or is there another to be checking.

thanks much for your help

 

See my post #2 in this thread for the JTIS section on the SRS (Supplementary Restraint System).

A complete description of the sensors with lots of diagrams.

Graham

 

Graham

your reference is quite helpful expecially after re reading the posts the this thread. Can help confirm wiring colors? UY, U, RW? The nomenclature for wiring colours is different in the US and I need to get "trained" for my new car.

I plan to investigate the airbag fault once again on Tuesday.

Thanks for your help

Ryejag Howard

 

Good to hear it's helping you make sense of this over-complicated airbag system. You'll have seen from the thread how much effort it has taken members to troubleshoot issues with the sensors and harness.

The UK wiring colours are:
B Black
G Green
K Pink
N Brown
O Orange
P Purple
R Red
S Slate
U Blue
W White
Y Yellow

D Dark
L Light
M Medium

The first letter represents the main colour and the second letter is the stripe.

UY = Blue with Yellow stripe; U = Blue; RW = Red with a White stripe.

Graham

 

Hey Rye.. What code sequence is flashing on the airbag light? That will help narrow it down. In my "hunting" for the fault, I found it was NOT the Hall Effect sensor, (which you will easily see when you take the seat out). But instead, the connection to the side airbag which is in the shoulder area of the seat. It is a PITA to get to. MC

 

I'm marking this as 'Resolved to help others looking for an answer because you found + fixed the problem.
I know ryejag still has a problem.

 

Thanks for all the info, I need to read more on this issue.

 

I removed my seat yesterday, cleaned all contacts with contact cleaner, then connected and reconnected all airbag related connectors. Also removed the seat hall detector and cleaned that as well. The 4 pin connector was damaged, so I used "nylon tye raps" to secure it. The clip mechanism was broken. so far so good on the repairs. I do not understand how the hall detector works, so would appreciated any input on that matter.

thanks to all for sharing your thoughts and experiences!

RyeJag

 

Back again.. particular thanks to GGG, Graham and Italianguy63 for guidance in resolving my airbag code 2-2 problem.

 

A fancy name for a simple principle. The 'Hall effect' sensor is, as you have found, on the underside of the driver's seat.

It consists of a steel blade attached to the seat slide. When the seat is moved forwards or backwards, it causes a magnetic field disturbance as the steel blade passes through the sensor. This creates an output signal to the Restraint Control Module. This signal indicates when the seat is too close to the steering wheel and the RCM disables the second stage output of the driver air bag module to prevent injury if the airbag was deployed at full force in an accident.

Malfunction of the sensor or associated circuits causes the SRS indicator (that annoying little yellow warning light in the Instrument Cluster) to illuminate.

Graham

 

Graham,

I seem to have a problem with mine. As noted in another thread, I have the Code 4-9, and have cleaned all connectors and verified proper electrical connections up until the BW/RW leads in the main yellow connector, FC9-23 and FC9-24. The flash code remains. So now I'm thinking the sensor itself might be broken.

- Is there a good way to test this type of hall effect sensor?
- Can you buy a replacement sensor somewhere?


Cheers from the Alps!

 

We don't hear of many, actually I can't think of any hall effect sensors 'going bad' in these cars, not even the really old XKs (thinking 97-98 here).

I can't recall if there is one on the passenger side, if there is, look at its condition and relative proximity to the rail and seat. Perhaps its physically damaged or out of alignment?

Barring all that, salvage yards should have a ton of these available, as the demand for them just isn't there.

 

I don't think there is one on the passenger side. The sensor only seems to be actuated when the seat is ridiculously close to the steering wheel, like if a 5-year old would drive the car. On the passenger side I suppose the airbag is further away, so the two-stage ignition is not required.

Do you happen to know of a way to measure the operation of this sensor? I don't even really know what is supposed to come in on the wires connected to it...

Having such a sensor go bad indeed sounds strange, so perhaps the issue lies within some other cabling. Where does the driver side seat harness end up?

 

One more item to work on related to this air bag connection under the seat. Just as the weather started warming up, I started getting the 2-2 blinking fault again. I was considering just replacing this connector under the seat with a new one, or splicing it with male/female bullet connectors. But as I was examining the 2-pin connector, I noticed for the first time, that there was a metal clip that bridges both connectors in the harness simply by resting against them.





The clip comes apart from the connector, and I opened the clip so the tension was greater against the pins, AND for an extra measure, I cleaned the contact points which were a little black ...possibly a little dirt.



After I polished them up, re-installed it, plugged it back in, the 2-2 light didn't come on as it did the last three days in a row.

Just something else for those troublesome 2-2 diagnosticians to tidy up. Hope it helps someone down the road.