Scary handling!

I've recently experienced a situation where my FL2 has induced massive oversteer when accelerating left out of a junction. I don't mean aggressive acceleration but a little spirited. It's handled perfectly all it's life but, instead of the normal front wheel drive or reassuringly safe four wheel drive it felt like giving a rear wheel drive a right boot full of throttle - just like driving onto oil or ice with the rear trying to swap ends needing to steer into skid to put back in shape.

This has happened at different junctions both on dry roads.

My FL2 has done 111k miles. Had minor problems with handling prior to new tyres all round and all tracking done and all then came good again until these unsettling experiences. Have had the LR Pinion bearing fix on the rear diff twice. The last time just a few months ago. Thought it was a rear shock but they seem ok (as far as it's possible to tell). The dealer has checked all mounts and torqued everything up before too with no wear reported. No leaks on the shocks reported. In a straight line it's ok. No wandering etc.

I'd like to know if anyone has had similar experiences to mine or may have any ideas.

Might be a worn front driveshaft inducing torque steer, alternatively are there any warning symbols appear? Could be a broken rely for ring giving false info to sensors

freelance said:

Might be a worn front driveshaft inducing torque steer, alternatively are there any warning symbols appear? Could be a broken rely for ring giving false info to sensors

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Thanks.

Doesn't feel like torque steer, although I suppose if one front wheel looses traction due to driveshaft issues or sensor input, the Haldex cuts in, applies power to the rear which under throttle and steering input upsets all the dynamics. I'd tried to remember if I'd seen any lights flick up on the dash but nothing did as far as I recall. I'd expect the dealer to check any logs of sensor malfunction etc. I suspect it's going to need more than the usual grease monkey to isolate the problem - in every other respect it behaves as you'd expect and this I've not been able to repeat, at least to the same degree. I did a similar corner with DSC off but that didn't repeat it.

That should spell reluctor ring, or even n/s track rod end or steering rack fault

freelance said:

That should spell reluctor ring, or even n/s track rod end or steering rack fault

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The reluctor ring sounds favourite to me. Everything else has checked out ok and come back NFF, but, I'm not surprised that the dealer hasn't found this. I don't think they even considered it. The next thing is how safe is it if there is a problem. I can live with it if I know the circumstances when it decides to throw an error, but, if it's likely to do it anytime, especially at speed that's something else.

I think I need a good LR independent to look at it.

Thanks for you help

There is no reluctor ring on a FL2 so that's why the dealer hasn't considered it!

To be honest without experiencing the fault and monitoring the various sensors and readouts on the car when it happens it will be very difficult to determine what's causing it.

Can you regularly repeat the issue?

td4van said:

There is no reluctor ring on a FL2 so that's why the dealer hasn't considered it!

To be honest without experiencing the fault and monitoring the various sensors and readouts on the car when it happens it will be very difficult to determine what's causing it.

Can you regularly repeat the issue?

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Unfortunately I wish I could. It's happened twice but I've tried and been unable to, at least not to anywhere near the same extent, but then I'd don't want to risk putting it into the green stuff. Finding a suitable space isn't easy short of using a carpark at an unsociable hour.

How does the FL2 monitor ABS and wheel rotation if there isn't a sensor on the shaft? There must be something somewhere...

Am sure it's a sensor induced response but, as with all intermittent problems, it's a pain to isolate and diagnose.

It uses a magnetic sensor in the wheel bearing to determine wheel speed.

Plus the diag in the module is good at picking up faults with the wheel speed sensors so if there was something wrong there it'd flag.

What's your wheel alignment like and have you had it adjusted recently? Maybe the steering angle sensor needs zeroing

td4van said:

It uses a magnetic sensor in the wheel bearing to determine wheel speed.

Plus the diag in the module is good at picking up faults with the wheel speed sensors so if there was something wrong there it'd flag.

What's your wheel alignment like and have you had it adjusted recently? Maybe the steering angle sensor needs zeroing

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Wheel alignment was done when the tyres were changed three weeks ago. All within spec. Have been getting 26k to 29k miles on each set of tyres which I think is pretty good and indicates that everything is pretty much in order.

How is the steering angle zero'd? I have a BMW that you simply turn full lock one way then right across to the other while stationary. Is the FL2 the same? Mine is a 2008 model with I suspect hydraulic steering rather than electric. Correct me if I'm wrong, but, it doesn't need zeroing if that is the case.

I have a healthy disrespect of claims that software picks all valid errors (have written software for 35 years). What valid fault conditions is it likely to detect as opposed to a valid trigger? Are they recorded too?

I think I'm going to have to wait until it happens again then get it looked at then. Thanks for the response. Much appreciated.

To zero the steering angle sensor then diagnostic equipment is needed to tell the steering angle sensor the wheels are straight ahead.

Unfortunately the BMW method won't work

It's fristrating these issues (and scary!) but they're very difficult to get to the bottom off especially if the car thinks it's behaviour is "normal" as the sensors are all reporting correctly.

That was why I asked about the wheel alignment as if the steering angle sensor isn't dead ahead then the car in combination with the longitudinal and lateral sensor thinks it's going Round a bigger bend then it is and reacts to keep the car on the road.

td4van said:

To zero the steering angle sensor then diagnostic equipment is needed to tell the steering angle sensor the wheels are straight ahead.

Unfortunately the BMW method won't work

It's fristrating these issues (and scary!) but they're very difficult to get to the bottom off especially if the car thinks it's behaviour is "normal" as the sensors are all reporting correctly.

That was why I asked about the wheel alignment as if the steering angle sensor isn't dead ahead then the car in combination with the longitudinal and lateral sensor thinks it's going Round a bigger bend then it is and reacts to keep the car on the road.

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I know the tracking was good, but whether or not that included zeroing the steering - I don't know. I suspect not. However, the LR dealer had it for a day to investigate - they may have done so.

While it happens only under those circumstances I can live with it while I zero-in on the problem/cause/circumstances. If it starts to throw in other random sensor MIS-reads and responses then it becomes more worrying.

Fortunately my wife works for a major manufacturer of garage diagnostic equipment. She suggested last night that the next step may be getting it into their training workshop for a serious shakedown. It may be more productive than back to LR or LR Indy. A win-win it sounds to me. Free diagnostics for me and a hard to diagnose fault for them to investigate. Might get the injectors and glow plugs checked at the same time

That does sound a win win all round!!!

Good luck and hope they can find something up with the car