Steering Locked Whilst Driving!

[electricmike]

Took delivery of 1 year old T180 and the wife loves it, until going around a round about the steering locked and pulled her across 2 lanes. luckily no accident as little traffic at the time. i rang the dealer who asked if we could drop off the car in a couple of days and if we wanted a courtesy car we would have to wait till next week. i suggested that the car is probably unsafe to drive so they then suggested I get in touch with the RAC and they may even organise a replacement car.

I could not understand this fault and as we arrived at the dealer with the RAC i thought i would check the Battery for a loose terminal, hold and behold the Battery had not been installed properly and both terminals were loose. when the dealer saw this their attitude completely changed organising a car and promised to make a thorough investigation.

Makes you wonder if the Battery ever runs down this fault could be repeated?

Also what compensation should i be seeking, considering this negligence could have caused a fatal crash. the RAC documented the fault.

[anchorman]

Welcome to the club Mike.

We have had very occasional reports of these scary steering issues. The steering is driven by an electric motor and it is linked to the VSC in such a way that in the event of a skid it will assist you to turn the right way to correct a skid and resist but not prevent you from turning the wrong way and making things worse. It also makes a convenient way of combining a steering angle sensor to work in combination with the VSC yaw sensor under the passenger seat.

I don't want to rain on your parade and I sincerely hope the fault is cured but I think what you are saying is that the Battery connection was so poor that it completey broke the circuit and cut off power to the steering motor? TBH I'm not sure that wouldn't have caused an array of other problems. To start with, would the engine run with the Battery disconnected? I also think the speed sensors might throw up VSC and ABS faults if the power went down. In reality if the Battery did develop a fault that you suspect might cause a steering malfunction it would have to be completely open circuit as the alternator would usually provide enough "instantanious" voltage to keep everything powered up as long as the engine was running. There is a member called shcm who looks in and is involved with the deign of these systems who may well comment further.

Now with the regard to your compensation the difficulty will be in proving who was responsible. Your contract is with the seller who is responsible for selling you a safe vehicle but I don't think all garages check every nut and bolt and if it went to court a test of reasonableness will apply. You also have to get them to admit that they agree that the battery was the cause. I guess you should put it to them and see what they say. I personally don't think you will get a lot but your negotiating might have to be based on how they react. Whatever they say try for a bit more. If they say you can have nothing, try to get something knocked off your first service. If they say you can have a free service, try and get two!

What you really want is an assurance that they have checked every aspect of the steering and ask them to demostrate it by explaining exactly what they have done. The other thing is that until enough time has passed for you to convince yourself all is well that you and wifey hold that steering wheel properly - just to be on the safe side.

All the best

steering.pdf

[electricmike]

Welcome to the club Mike.

We have had very occasional reports of these scary steering issues. The steering is driven by an electric motor and it is linked to the VSC in such a way that in the event of a skid it will assist you to turn the right way to correct a skid and resist but not prevent you from turning the wrong way and making things worse. It also makes a convenient way of combining a steering angle sensor to work in combination with the VSC yaw sensor under the passenger seat.

I don't want to rain on your parade and I sincerely hope the fault is cured but I think what you are saying is that the battery connection was so poor that it completey broke the circuit and cut off power to the steering motor? TBH I'm not sure that wouldn't have caused an array of other problems. To start with, would the engine run with the battery disconnected? I also think the speed sensors might throw up VSC and ABS faults if the power went down. In reality if the battery did develop a fault that you suspect might cause a steering malfunction it would have to be completely open circuit as the alternator would usually provide enough "instantanious" voltage to keep everything powered up as long as the engine was running. There is a member called shcm who looks in and is involved with the deign of these systems who may well comment further.

Now with the regard to your compensation the difficulty will be in proving who was responsible. Your contract is with the seller who is responsible for selling you a safe vehicle but I don't think all garages check every nut and bolt and if it went to court a test of reasonableness will apply. You also have to get them to admit that they agree that the battery was the cause. I guess you should put it to them and see what they say. I personally don't think you will get a lot but your negotiating might have to be based on how they react. Whatever they say try for a bit more. If they say you can have nothing, try to get something knocked off your first service. If they say you can have a free service, try and get two!

What you really want is an assurance that they have checked every aspect of the steering and ask them to demostrate it by explaining exactly what they have done. The other thing is that until enough time has passed for you to convince yourself all is well that you and wifey hold that steering wheel properly - just to be on the safe side.

All the best

thanks for your comprehensive reply, i agree that our confidence needs to be restored in the Ravi, e.g. will it lock at 70 mph on the motorway? and your assessment about the Battery is also true. with more thought things to consider are the following:

1, toyota must have a fail safe for this to ever occur.

2. the system has been around on other cars for a number of years and well tested.

3. i imagine the car has a multiplex system (bmw call it canbus) where a single cable is used to operated several devices.

on this basis the loose terminal produced a spike that happened to be at the same frequency and amplitute that controls the electric steering lock. if this is the case it maybe possible to replicate the fault by tapping a disconnected terminal on the Battery when the engine is running.

i will update this post when i know more from the dealer.

[electricmike]

Took delivery of 1 year old T180 and the wife loves it, until going around a round about the steering locked and pulled her across 2 lanes. luckily no accident as little traffic at the time. i rang the dealer who asked if we could drop off the car in a couple of days and if we wanted a courtesy car we would have to wait till next week. i suggested that the car is probably unsafe to drive so they then suggested I get in touch with the RAC and they may even organise a replacement car.

I could not understand this fault and as we arrived at the dealer with the RAC i thought i would check the battery for a loose terminal, hold and behold the battery had not been installed properly and both terminals were loose. when the dealer saw this their attitude completely changed organising a car and promised to make a thorough investigation.

Makes you wonder if the battery ever runs down this fault could be repeated?

Also what compensation should i be seeking, considering this negligence could have caused a fatal crash. the RAC documented the fault.

just got of the phone from the dealer and they owned up and confirmed that the Battery caused the steering lock. so all you t180 owners check your Battery terminals!! For the compensation they have offered a free 2nd service (£230) i am pushing for a towbar.

[shcm]

There is a member called shcm who looks in and is involved with the deign of these systems who may well comment further.

Glad to here everybody is safe, that is the main thing.

It would be inappropriate for me to comment on any one particular system, however, I can make some general comments.

First, there is a "fail safe" - there is still a mechanical connection between the steering wheel and the wheels. The motor just provides assistance. However, I agree that over time, vehicle manufacturers have made other changes to steering design (e.g. to improve feel/performance in other areas), such that now, without assistance, it may well feel "locked". I've witnessed loss of assistance on a 4x4 (not Toyota) and it was certainly a struggle for the chap (who wasn't exactly small) to wrestle it to safety.

Loss of assistance on EPS (electric power steering) is certainly in theory no worse than loss of a mech/fluid based system.

On a small car at low speed, the current into the steering motor to provide assistance can typically be up to 120 amps peak (That's a lot in this context!). On something like the RAV, it is probably a fair bit more. However, that current level will reduce by a large percentage with increasing speed.

The vehicle electronic systems should still work even with the Battery disconnected, the alternator will provide the supply, as it does most of the time anyway. However, it's not unreasonable during short periods of high current demand for the Battery to act as a reservoir and make up the short fall. The RAVs alternator is something like 130A rated, so it's not unreasonable to expect some current from the Battery to be involved during high demand. This however, should be mainly at low speed, where, it could be argued that loss of (or reduced) assistance is less critical. I would expect the EPS ECU to store a fault code, if the system can't provide the target assistance.

The system should still work independently with the loss of the CAN bus, although the whole vehicle stability thing will probably be at a reduce functionality and you'll get a warning and a fault stored.

There is an electric steering lock involved with keyless entry on T180/XT5. Not sure whether that would kick in if all vehicle power supply was lost, or voltage pulled down to a low level. I can see two sides of an argument for that one.

I'm surprised with a loose battery terminal, that the starter motor didn't struggle to start the car.

However, with the engine running a battery disconnect can generate a large voltage transient (spike if you like) on the vehicle supply. We refer to it as a load dump. 80 to 120V is not uncommon, although some vehicles help by clamping the voltage at the alternator.

A simplified analogy, is probably something like a large pump, pumping water though a pipe to a reservoir and you instantly blocking the pipe. The resulting pressure increase can destroy pipes etc.

I was only discussing the probability of loose battery terminals and load dumps the other day with a colleague. We were speculating it was small, but at least you have just reinforced why we need to take care with it.

We have to design the electronics to survive load dumps and it can be a real pain for us at times. Some systems have to work without degradation though this, others can be specified to shut down briefly. I'd expect the EPS to work though it, possibly at reduced functionality.

Inadequate load dump protection in a control unit can destroy other more sensitive electronics in there, so, when you get the vehicle back, just check everything else seems to be working properly.

My employer doesn't make the EPS system on the RAV by the way. Fault conditions and scenarios are taken very seriously during design and development and even more so with things like steering and braking systems. We try to cover all reasonable scenarios and allow for them. We are still human (allegedly) though.

I'm sure you'll be back to enjoying the vehicle when it is sorted.

Cheers

[duncerduncs]

just got of the phone from the dealer and they owned up and confirmed that the battery caused the steering lock. so all you t180 owners check your battery terminals!!

Just for the benefit of others on the forum, this fault could affect XT5 owners too

[shcm]

Just for the benefit of others on the forum, this fault could affect XT5 owners too

Eh?? Sorry Duncs, but while that is a technically correct statement, I think it could be a bit misleading.

If this is due to loss of Assistance, then it is possible with all 4.3 RAVs.

If it is due to the electric security steering lock (and I can't believe they haven't thought about faults in that one very carefully), then yes it will just affect models with the keyless entry (push button start). I'm assuming the elec lock is only on the keyless models - I haven't checked.

Unless you know something different?

[electricmike]

http://www.feebleminds-gifs.com/electric-shock.gif

Just for the benefit of others on the forum, this fault could affect XT5 owners too

Eh?? Sorry Duncs, but while that is a technically correct statement, I think it could be a bit misleading.

If this is due to loss of Assistance, then it is possible with all 4.3 RAVs.

If it is due to the electric security steering lock (and I can't believe they haven't thought about faults in that one very carefully), then yes it will just affect models with the keyless entry (push button start). I'm assuming the elec lock is only on the keyless models - I haven't checked.

Unless you know something different?

hi beside experimenting with image placement i think this fault could occur on any car that is multipexed and has an electric steering lock, more gadgets more complexity = more problems in the future, however if we do not embrace technology we would still be using a horse and cart. some would say no bad thing!

[duncerduncs]

If it is due to the electric security steering lock (and I can't believe they haven't thought about faults in that one very carefully), then yes it will just affect models with the keyless entry (push button start). I'm assuming the elec lock is only on the keyless models - I haven't checked.

The only way I can see you activating the steering lock on XT3, XT-R, XT4 & SR180 models would be to remove the key on the move!

Electricmike's post suggested that T180 owners should check their cars, I was trying to be helpful by reminding XT5 owners too

I'm with AM on this one, I think there is more to it than the Battery connection...

[vivianM]

Took delivery of 1 year old T180 and the wife loves it, until going around a round about the steering locked and pulled her across 2 lanes. luckily no accident as little traffic at the time. i rang the dealer who asked if we could drop off the car in a couple of days and if we wanted a courtesy car we would have to wait till next week. i suggested that the car is probably unsafe to drive so they then suggested I get in touch with the RAC and they may even organise a replacement car.

I could not understand this fault and as we arrived at the dealer with the RAC i thought i would check the battery for a loose terminal, hold and behold the battery had not been installed properly and both terminals were loose. when the dealer saw this their attitude completely changed organising a car and promised to make a thorough investigation.

Makes you wonder if the battery ever runs down this fault could be repeated?

Also what compensation should i be seeking, considering this negligence could have caused a fatal crash. the RAC documented the fault.

On all my pre Rav4 cars with power steering I checked each one on how difficult it was to steer with the engine off - in those days I had a long drive down a slight hill - all could be steered with quite a heavy action some much heavier - you should all try this out on an empty straight road but note that the brake servo will not operate and much heavier brake pedal use is needed to stop!!

Has anyone tried pushing the start/stop button whilst travelling to see what happens - someone braver than me, please, and does the steering lock cut in right away?

Both in and out of gear!

If Anchorman is assisting at the local station on this Sat afternoon we could have a try!!

My T180 service is booked for tomorrow am so will report if the engine managent upgrade is done and if there is any noticed change.

Guy

[anchorman]

I can't believe that the system would lock the steering with a loss of power. The airbags have capacitors to hold a charge and I'm sure the steering lock will as well. What Toyota (your dealer) are advocating is that in the event of an accident where the Battery supply was severed but the vehicle was still on the move, then the steering would lock. It sounds like a service manager trying to give a nice warm feeling to me. He is suggesting that if an alternator fault caused the fusible link to go then the steering would lock??? He should have engaged brain before engaging "fob" mode.

We have heard of these problems before and like the others I think it has lost the power assistance which would no doubt caused a shock to your mrs and would have felt like it had locked OR like somebody else once suggested, the steering has applied the resisting force it would apply in the case of a skid when there was no skid and in fact "powered" the steering motor to one side.

I would still urge extreme caution until you have become confident that the problem has gone.

The vehicle in question was a T180 and when I get a bit of time I will search for it.

[shcm]

Electricmike's post suggested that T180 owners should check their cars, I was trying to be helpful by reminding XT5 owners too

Has anyone tried pushing the start/stop button whilst travelling to see what happens - someone braver than me, please, and does the steering lock cut in right away?

Guy, I'm fairly sure that the driver's door has to be open before the lock goes in, or at the very least there is a few minutes delay after ign off. Don't jump out if you try it :D.

I can't believe that the system would lock the steering with a loss of power. The airbags have capacitors to hold a charge and I'm sure the steering lock will as well.

There's usually a whole heap of supply drop out and transient specification to meet with probably nearly every, it not all ECUs. You know from your former occupation and area how keen they are on their piles of specs and testing.

There was probably a whole load of supply transients occurring with the Battery loose, but, no, I can't believe, they wouldn't have taken account of that during the system design. Stranger things have happened, but I certainly wouldn't put money on it chucking the steering lock back in.

OR like somebody else once suggested, the steering has applied the resisting force it would apply in the case of a skid when there was no skid and in fact "powered" the steering motor to one side.

Oh, you are going to love lane guiding with "haptic" feedback then. Applies slight steering resistance to try and keep you in lane, if it thinks you are straying out. (No, I'm not completely convinced either).

Hours of fun to be had repainting lane markings to guide you gracefully into concrete bridge supports

Maybe the large vibrating thing under the seat to simulate a rumble strip, if you stray out of lane, is a better option. Mind you, that might encourage some people to drive down the middle of the road. Could feel like sitting on a washing machine on spin and some people might enjoy that.

[anchorman]

Could feel like sitting on a washing machine on spin and some people might enjoy that.

Petrol pump is good if you get it just right. I once put 483 gallons of 4 star in a company BMW :D

[Red Yaris 54]

I once put 483 gallons of 4 star in a company BMW :D

And that was a diesel car!! :P :o ;)