Hi all,

I'm sure this has been covered a million times but just wanted to check my diagnostic thinking makes sense.

My car is a 2002 S-Type 3.0 with a manual gearbox. The other day I got a slight bit of understeer on a tight wet corner (it came on awful tyres that I haven't changed yet) and ABS FAULT and DSC NOT AVAILABLE came up on the dash.

I've tried the easy things first. Changed the battery for a known good one (tested at a solid 12.6 volts) which made no difference. Tried a reset by leaving the battery off overnight. No difference.

A local garage read the codes and said it's showing as three faults. Steering angle sensor, ABS reluctor ring missing a tooth on offside front and Wheel speed sensor offside front bad signal.

My thinking is that the main fault here is probably the wheel speed sensor offside front. I haven't even managed to find a source for front ABS rings but I think that a faulty sensor could return a report that it's missing a tooth when it's actually fine.

Any insight from those who know these cars better would be appreciated

 

You need a tool to clear most faults including ABS ones but the light should go off if the problem is fixed / goes away.

It's easy to over-think and when you have multiple codes clearing and seeing which if any comes back may be best. That or do the simple/cheap stuff (tyres?) and hope.

 

Thanks for this. I'm happy to do tyres, but I'm feeling that the most likely fault here is the speed sensor?

It seems like on the front, rings are unlikely. I just want to fix it - I can get a garage to clear old faults later on

 

Not a Jag guy, but have years of experience on LR with similar ABS problems. Almost always wheel speed sensor, although slipping conditions do not typically cause the fault, fault comes before you need the abs. probably 50% of the time I have found someone has left the speed sensor cable out of the correct holder during a brake job and the tire has rubbed a hole in the wire.

Good luck!

 

I'm hoping that this is the case. A few things point to it for me.

I guess that the slip just let the car realise that the fault was there. Odd that it didn't pick it up before and it picks it up now after resets, but I guess that's what happened.

My other potentially useful symptom is that it only shows ABS FAULT on startup. DSC NOT AVAILABLE comes only after exceeding 20mph or so, so I hope that the basic fault is the easiest and cheapest - speed sensor.

If anyone can tell me how to check the front ABS rings for damage (I haven't checked yet, but it sounds like they're sealed? Is the only way to mark a tooth and to count them all through the hole where the speed sensor sits?)

 

Almost zero chance the reluctor rings are damaged. They are integrated in to the hubs and cannot be damaged. One fault that does happen on LR's is the hub bearing wears a little bit and the signal becomes intermittent causing an ABS fault, usually that is only on vehicles with 175k+ on the clock.

 

Thanks, this was my thinking so I'm relieved to hear someone else thinks so too.

My car is on 190k but had new bearings on the front last year, at 186 or 187k I think. I have details somewhere in my paperwork at home

 

I don't think you will. AFAIK, the rings are integral to the front hubs. The hubs are sealed assemblies. The rings are well protected from the elements inside there. It's hard to imagine them getting damaged. I recently replaced the front hubs on my '02 and played around with the old units. I couldn't see any means for disassembly without destroying them.

I added details of my experience to this FAQ, starting at post #20. Not a difficult job at all. The only tricky part was breaking the four bolts free, but if you turn the steering you should easier access:

https://www.jaguarforums.com/forum/s...-repair-39466/

Back to your present faults, I wonder if your mechanic's scanner is giving inaccurate definitions. It's best if you have the 5 digit code, such as C1234. Many scanners display generic definitions that can be different than the official Jaguar version and possibly lead you astray.

Since your fault suddenly appeared in a sharp turn, I wonder if there's a problem with the sensor harness. It may have flexed just right and failed. I'd suggest starting with a good visual inspection for any chafing or kinks.

If they look good, you could do a resistance check of each sensor from the controller. I don't know the expected value, but all four wheels should be close. Wiggle the harness at each wheel while watching the meter, in case of an intermittent fault. The resistance checks are not conclusive. If a sensor fell out of the hub, it would still pass, but you'd see that on a visual inspection.

Piece of cake to replace a sensor. A simple clip secures the sensor (and integrated harness lead) to the inboard side of the hub. Some flexible clips secure the harness lead to the suspension. The connector is under a plastic shield on the body.

If you do replace a sensor, make sure you get OEM or equivalent. The hubs I installed were Timken brand and included new sensors and leads. The leads plugged right into the main harness, no problem. But the sensor itself was slightly different. If I ever have to replace one of these sensors, I'll have to find one that fits the Timken hub. If your hubs are still original, make sure you don't get this different style sensor.
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If you had the hubs replaced it is possible they did not clip the sensors in to the retainers correctly and the tire has worn a hold in the wire. The other possibility is your rear hubs are throwing the fault. For zero dollars you can check the front sensor wiring to see if it shows any signs of damage. Otherwise you need a scanner to determine which sensor is throwing the code. After I find the offending sensor I always swap it left to right confirm it is a bad sensor and not a bad hub bearing.

Good luck.

 

Thanks kr. It was a little frustrating - I would've liked to get the codes for myself. I might get chance on Monday/Tuesday to take it elsewhere.

And thanks for your tips - that's very helpful. I'll have to dig out the bills for the work to see what I have. I'll also take the wheel off and give it all a good visual inspection. I'm really glad to hear from separate sources that the front rings are as I thought - sealed and integral. It makes me think more and more that an issue with sensor/sensor wiring is causing it, and that should be cheap and easy to fix