RX400h drivers seat won't move forward or back

[Imackie61]

Just tried to move the seat forward on my 2007 RX400h and it just makes a clicking sound. All the other electrics on the seat work, up, down, lumbar, etc.

I've tried to check whether anything has got lodged in the rails but having difficulty accessing them under the seat. Does each seat function have its own motor?

Any advice appreciated. Thanks

[Barry14UK]

Fortunately not had to check on my RX yet but seats I removed from a  BMW each had a motor and as I recall it was necessary to unbolt seat to access it, bit of a pain! 

You don't say if the other seat is affected which could give a clue.   

[Imackie61]

The passenger seat works fine. The switch that moves the seat back and forwards also moves the seat up and down. The up and down work fine so does that mean there is one motor for both actions given it's the same switch?

[Barry14UK]

There is one motor for each seat, at least on my BMW but it does not have lumber adjustment so could make a difference with RX). The one motor operates the different actions on my Beemer, just as one motor does in a washing machine.  This video may give you some idea of what's under the seat and how to access it, although it's for the purpose of replacing seat covers. The fact that yours clicks suggest the movements is obstructed, even though you have checked this as well as you can. Sorry can't help further. 

 

[Haylands]

I don't have time to watch that video but every electric seat I have had has had one motor for each plane of movement, the polarity is reversed to go the other way. You should have one motor for forward and back, one for up and down and one for the recline...

There will be an ECU to control the movement which will be handled by canbus, these tend to work or fail so I would put my money on the electric motor that does back and forward.

Disconnect the Battery after putting the seat in it's highest position, then unbolt the four bolts, one in each corner, it can be tricky getting to the forward or back ones if the seat is in just the wrong position, when unbolted tip the whole seat back to get to the plugs underneath, protect the door threshold when lifting the seat out..... Swap the motor and hopefully refitting it will be easier, put it back in, plug it in, connect the Battery and move the seat all the way back to do the front bolts and vice versa..

A pretty easy DIY job if you can get a spanner on the bolts, and you always find some money under the seat to offset the cost....

[Herbie]

48 minutes ago, Haylands said:

A pretty easy DIY job if you can get a spanner on the bolts, and you always find some money under the seat to offset the cost....

[Barry14UK]

2 hours ago, Haylands said:

I don't have time to watch that video but every electric seat I have had has had one motor for each plane of movement, the polarity is reversed to go the other way. You should have one motor for forward and back, one for up and down and one for the recline...

There will be an ECU to control the movement which will be handled by canbus, these tend to work or fail so I would put my money on the electric motor that does back and forward.

Disconnect the battery after putting the seat in it's highest position, then unbolt the four bolts, one in each corner, it can be tricky getting to the forward or back ones if the seat is in just the wrong position, when unbolted tip the whole seat back to get to the plugs underneath, protect the door threshold when lifting the seat out..... Swap the motor and hopefully refitting it will be easier, put it back in, plug it in, connect the battery and move the seat all the way back to do the front bolts and vice versa..

A pretty easy DIY job if you can get a spanner on the bolts, and you always find some money under the seat to offset the cost....

Apologies to OP, I was going from memory.  I have just checked the seat underside of a 2001 E39 BMW 530i, that I broke for spares last year and a quick check shows that it has at least 4 motors that are immediately visible.  There is no lumber support but it does have an extending seat squab. At least two of these motors have an intermediate rather than direct drive, so would work rather like the drive to the powered sun roof on that car, although there is only the one motor for moving the drive each way to the roof.  So if the seat slightly flexible drive is similar on the Lexus, it could be this is the problem along with operating arms (as was problem with the sun roof on that BMW, the motor being OK), or the motor could could be faulty. 

[Imackie61]

Thanks everyone for your replies. For no reason, as I'd done nothing to resolve it, the forward and back switch started working again. We shall see whether it re-occurs.

[Illogan]

1 hour ago, Imackie61 said:

Thanks everyone for your replies. For no reason, as I'd done nothing to resolve it, the forward and back switch started working again. We shall see whether it re-occurs.

Ahah!     The recent problem may well have been caused by a loose or (possibly) corroded connection.     Like so many things electrical - fingers crossed!

[Haylands]

In my experience an intermittent failure is, more often than not, down to dirty switch contacts inside, pull the knob off and jet wash inside as best you can with electrical contact cleaner aerosol.... also move the switch numerous times to help clean the contacts... usually does the trick....