First off, my XJR arrived at my house last night and is now safely tucked away in the garage. I'm very excited.

It is having transmission problems. Before I fully commit to swapping the transmission, I definitely wanted to know what codes it was throwing.

I borrowed my buddy's Cen-Tech OBD scanner (item #98568 from Harbor Freight) and was able to successfully read the codes this morning.

The first code I read was C1175.

There are several existing threads regarding this code.

C1175 = Left rear wheel speed sensor
C1165 = Right rear wheel speed sensor

It appears that the rear outer CV joints have a ring on them from which wheel speed is determined. Sounds like either the sensor itself can become loose or corroded, OR the actual ring on the CV joint can corrode or become loose and slip.

I even came across this handy thread where Jim was kind enough to post instructions on how to replace this ring: Speed Ring Replacement

However, pretty much all of the information I've dug up about the C1175 error code is coming out of the X-type groups.... nothing from the X308 fellows.

So I ask... does C1175 mean the same thing for the X308 design, and does Jim's directions apply to the X308 CV joint as well?

Thanks!

-Caleb

 

The X Type and the XJ8 are very different at the rear (all over actually). The ABS ring failure is peculiar to the X Types only. The ABS ring on the XJ8 is part of the hub rather than the drive shaft (which has a Universal Joint not a CV Joint on the XJ8) and I've never heard of one failing except where a mechanic breaks it.

It is more likely that the abs sensor itself is the fault.

 

Thanks for the heads up B1mcp!

I went ahead and pulled the tire off to take a look. Turns out the ABS sensor is just behind the brake rotor, right out in the open:



A couple turns with a 5/16" socket and the sensor pulled right out:



It sounds like some people get this C1175 error because the sensor is dirty? This is what mine looked like right when I pulled it out:



I thought I read somewhere that you can test the resistivity of the sensor to see if it's any good? (or was that testing the wire leads that connect the sensor?)

-Caleb

 

I found several threads discussing the ABS sensors, and they all seemed to indicate that the sensor itself should have a resistance of between 1,000 to 1,200 ohms (1.0 to 1.2 kOhms). So, I grabbed the trusty Fluke multimeter and tested mine out.

Mine tested between 1,123 to 1,128 Ohms.

So... I'm going to assume that the sensor itself is good.

I also believe I've read that the ABS control module can be faulty, including some poor soldering connections.

I'm going to wash the sensor with dish soap, and re-install it, then start looking at the ABS control module.

 

I'm moving forward with the ABS control module unless/until someone stops me.

The ABS control module for the X308 XJR is located right behind the front grill, on the drivers side. It is fairly conspicuous due to all the brake lines coming out of it:



The entire unit consists of the control module, brake line bank, and pump, with a main harness connected on the left side.

Note: Don't be concerned if you do not see a zip-tie near your control module. That is a performance modification unique to my vehicle.



The main harness should be disconnected before removing the control module. In order to do this, lift up on the small handle-looking thing at the top of the main harness connection. Once lifted, the harness should pull outwards and disconnect:



Beneath the main harness connection is the ABS pump connection. Squeeze this connection on both the top and bottom, then pull outwards to disconnect:



More to follow....

 

Well crap! There are 4 E5 star-head bolts holding the control module in place. The top 2 were straight-forward and I had them removed in a couple of minutes. However, the bottom 2 are located in such a place that a frame rail is sitting about 3/4" in front of them. It would be enough space to unscrew the bolts enough to disengage them, but it is not enough space to get a socket in there. I also don't own any Torx box wrenches, so I'm pretty well screwed.

It's looking like I'm going to have to disconnect all the brake lines (which means draining the brake fluid), and then remove the entire controller, valve body, pump assembly. Well in order to do that I need to remove the 2 bolts holding the assembly in place from underneath. Well in order to do that I need to remove the overflow container behind the bumper. Well in order to do that I need to remove the front bumper....

ARGH! Was hoping this would be much easier than this. Should have known better. :-(

 

Caleb - You seem to be diving in very deep. If you have only done the resistance test on the sensor then I would want to do a lot more to check out the sensors before I pulled out the module.

I would try and confirm the sensor absolutely before going any further. I suggest:

- After cleaning the sensor, clear the codes and see if they re-occur?
- Check the voltage output from the sensor while the wheel is moving
- Check the continuity and resistance between the sensor and the module plug - it's a long way front to back and there could be a wiring problem along the way

So if you can confirm sensor resistance and voltage output at the module plug, and a code is still being flagged then that is grounds for pulling the module for further investigation.

 

I agree with Brendan. But in the meantime, check out this thread -

https://www.jaguarforums.com/forum/x...removal-37915/

 

I would do some additional diagnostic prior to taking the module apart -- it may indeed be the problem since I find it unlikely that both of the rear sensors failed - but checking any common connection point seems logical.


The sensors are normally very reliable -- whenever people talk about having a problem ............cleaning the sensors is always the first suggestion. But I have never heard of this actually fixing the problem ..... and I can't think of anyone every replacing one.

 

Well, I should probably mention that I have other reasons to believe that the control module is part of the problem. I'm also getting the error messages "ABS Unavailable" and "Traction Control Unavailable", which from what I read would indicate the control module. Cleaning the rear sensor might have cleared up the C1175 code though. I'll try throwing the wheel back on, clearing the code, and getting it up to 12mph. I believe that's the speed where the C1175 code would be activated if the problem hadn't been solved yet.

Thanks!

-Caleb

 

While you can, and should have clean wheel sensors, if you have other ABS TRAC issues, then you may have the pump issue.
You can remove the control module without removing or opening brake lines.
https://www.jaguarforums.com/forum/x...-repair-62539/