Last week of June I took Alice on a road trip to Denver and back, mainly because I was helping out my ex wife with some medical stuff. Car drove great, no issues aside from the ever blaring CEL from the EGR valve (I'm not allowed to work on cars in my condo's parking lot, so when I can get some time to sort that at a garage I will.) but the next day I started getting TCS Fail and ABS lights. Brakes are a little squeakier than normal, which may be due to the fact I've had to do some hard stops thanks to the massive amount of imbeciles that have moved to Colorado Springs. Have checked the rear floor boards for water or dampness, checked the majority of the fuses that I can find within reason. Gonna check the terminal's again on the battery but those were clean and that had recently been replaced (about 2 months before I got the big cat.) Randomly the light will go away, for a day or two, then will return. I'm wondering if when the car was on a slope and I had the parking brake engaged something got stuck or wedged somewhere in one of the calipers, as my brother has postulated with his grumbling about the complexity of the TCS and how it drove him bonkers. Thinking a caliper might be dragging as well. Is there a quick way I can check if it's not just a shot ABS relay? After reading some of the threads and realizing "Oh dear god, why are there relay's literally everywhere in this car?" I was curious to know if anyone had some "straightforward" relay diagrams for the ABS relays. I'm hoping they aren't buried somewhere in the depths of the dash.

 

Guessing can get expensive. A proper diagnostic tool is harder to come by but it might be worth it to check the module for DTCs before 'throwing parts' at the car.

Most of the faults I've had with customer's X300 XJRs were from the position sensor in either the TC unit (C1449 or C1495) or the TPS on the throttle assy (P codes).

Could be wheel speed related but without the faults read from the module you won't know what the module is 'whining' about.

bob

 

Alice's 1997 wiring guide for the ABS / TC can be found on page 70 , relatively simple wiring and components , no relay involved

Fuse are :

# 16 / 5 amp LH heelboard fuse box

# 7 / 30 amp LH heelboard fuse box

# 7 / 30 amp RH heelboard fuse box

http://www.jagrepair.com/images/Auto.../jagxj1997.pdf

Easiest thing first and most conman is the 4 wheel speed sensors dirty on the sensor face as well as the electrical connectors

The wheel speed sensors will read about 1300 ohms as a 2 wire pair as a " fundamental " reading from the modual connector under the hood

As a " functional ' reading they will read about 1.0 volts as a AC signal in the correct direction of tire spin

The sensors are plastic and can break if tried too hard to remove by prying from the outside

Motorcarman had a suggestion on cleaning or pushing the sensors out from the interior of the wheel hub I have not tried

There is a change in sensor part numbers through X300 production number in your VIN

The brake switch is involved and there is a upgraded switch involve

There are 2 switches inside the brake switch assembly and one independently controls your brake lights

The parking brake handle is not related

There are 2 wires that go under the cylindrical TC actuator that have the insulation go bad and crumble off

 

I was looking at that diagram you posted earlier. I'll go digging around and see what I can find when I can get her on a lift. I thought that the wheel sensors might be dirty, knowing that they can be fragile now is less fun. I'll ask my buddy about getting some actual diagnostics done. Will go through fuses again to make sure that those aren't blown, and will look for those crumbled wires on the module. Thanks for the input, will have updates come Thursday hopefully. @motorcarman Yeah, I'm of the generation that's "throw parts at it until it works" and I'm trying to teach myself how to diagnose things and actually trouble shoot and repair things correctly. Still have a lot...a lot... a lot more to learn. Thanks again guys. Will report in.

Edit - Are the ABS modules the same on the XJR as they are the standard XJ6? I'm considering getting my hands on one to practice out of a yard before pulling and working on my own.

 

No jacking required on getting to the wheel speed sensors and the sensors are on the top of each wheel hub

10 mm bolts

Some penetrating spray a couple of days in advance helps especially to get plenty in the boss the sensor fit in

Some have no problem at all in removal

Notice I have the sensor wire pairs in different colors in the pic , just click on the picture and click again to expand

The cylindrical TC actuator is in front of the ABS / TC module and the TC option is not always on each X300 example

 

The 4.0 liter ABS modules are 'Traction Control' and EXCEPT Traction Control. They are NOT interchangeable.

bob