Faulty Self-Levelling Lights? 07 GS450H

cpk · February 22, 2017

Driving home tonight was a real struggle. My lights are pointing as low as possible but only me in car and nothing in boot.

The levelling motors are working, they raise and lower when lights switched on but they are pointing down lighting up approx 3m of road!

I need to get it booked in (under warranty) but wondered if there was a quick fix to override the motors pointing down so I don't have to drive at 20mph if I can't use full beam!

NemesisUK · February 22, 2017

Level sensors on the suspension have failed? Check to see if one has broken.

Hangie · February 23, 2017

Just take screwdriver and raise them - there might be no fault of at all.

In general auto levelling is responsible to compensate extra weight in the car not to literally level the light. So first you need to have good reference point (setup with old school screwdriver) and then levelling system can work on top of that.

At least it was like that in all my previous cars and I really doubt it is different here.

finally to check the sensor park in front of the wall and press hard on the boot (when open) and observe if system is compensating for the extra weight in the back by lowering the light beam.

cpk · February 23, 2017

Thanks for the replies.

How do I check if the level sensors are broken? Any easy solution?

Hangie · February 23, 2017

Check my previous post. Just park in front of a wall and put some weight to the boot. If there is no reaction something is wrong.

cpk · February 23, 2017

I will do that tonight but suspect there won't be a reaction because the lights are pointing right down so they think there is already max weight in boot.

Might have to raise boot somehow!?

will try!

Britprius · February 23, 2017

7 hours ago, cpk said:

I will do that tonight but suspect there won't be a reaction because the lights are pointing right down so they think there is already max weight in boot.

Might have to raise boot somehow!?

will try!

There are height sensors on the front and rear of the car. Both are on the nearside suspension. The front one that easily be seen with the front wheels on a lefthand lock.

John

Lexus GS450H 2007 · February 25, 2017

I have just been quoted £606 to replace a sensor by Lexus Lincoln as the arm is detached but I fixed myself for £0!

Farqui · February 25, 2017

Well done, how had it been dislodged?

Was the Lexus quote without them looking at the vehicle, so a worse case cost?

cpk · February 25, 2017

What were your symptoms for Lincoln to come up with that charge?

Britprius · February 25, 2017

6 hours ago, Lexus GS450H 2007 said:

I have just been quoted £606 to replace a sensor by Lexus Lincoln as the arm is detached but I fixed myself for £0!

This is a common problem with the Toyota/Lexus leveling system. The connecting rods with the ball joint cups are made of cast zink, and are fitted to steel ball joints. There is a small rubber boot that is supposed to stop water and dirt getting into the joint, but it fails badly in this task particularly due to where they are situated. The result is a seized joint flexing the cast zink rod, and it snaps or pops off the ball.

It is easy to repair the old rod and lubricate it, but this is a short term fix.

The best way is to but some plastic cups with threaded ends, and use a piece of threaded rod to join them. These are readily available in various sizes. This makes for a rod that is adjustable in length to adjust headlamp height to a greater degree, and the plastic cups do not seize or need lubricant on the steel balls. This is the same system as used on the boot lid or tailgate struts where they do use plastic cups on steel balls.

The rods are not available as a replacement item only as a complete leveler at about £350 each.

John.

NemesisUK · February 25, 2017

Wow! That's expensive..

This is common on Mercedes as well, pretty sure I only paid £50 for a new sensor.

normski2 · February 25, 2017

This is quite a good post to have a nose through ....especially Steve's link to a fix for a broken rod.

Some problems may be headed off by the occasional greasing/checking of the ball joints. Going to check mine when I next do the slide pins in April.

cruisermark · February 25, 2017

I believe SGS Engineering sell this part for LS400 - might be worth asking them if they can knock one up for the GS

Britprius · February 25, 2017

22 minutes ago, cruisermark said:

I believe SGS Engineering sell this part for LS400 - might be worth asking them if they can knock one up for the GS

I am almost sure the electrical part is the same across the Toyota/Lexus range. It is only the mounting brackets, and the rod length that differs. I know the Prius unit is the same as the GS electrically.

John

Britprius · February 25, 2017

The sensor can often be repaired if that is at fault. It has three small springs inside made of steel. These rust and fall to bits. They can be replaced after cleaning the rest of the unit with springs from click type ball pens.

The sensor is in just about the worst place possible under the wheel arches. The front one could have been in the engine compartment worked off the roll bar, and the rear could have been placed higher and near the centre of the car "away from the wheels" and again worked from the roll bar.

John