First Problem in 3 years! Fuse I hope?

Spacewagon52 · May 4, 2018

Hi Guys!

Hope someone can suggest something here.

On the driver's door panel - only the driver's window switch works. The other three are dead. All windows work from their individual switches on the doors.

Central locking no longer works (on the drivers panel and the key).

The steering wheel does not actuate when the ignition key is put in place. The steering motors work from the knob on the steering column.

I have located the internal fuse box but I am baffled by which fuse might be the problem?

Any suggestions most welcome as I can't lock the car at this time!

PWR-1G?

P RR Door?

D RR Door?

Could it be a fuse in the engine bay?

ColinBarber · May 4, 2018

Unlikely to be a fuse in the engine bay.

D FR Door is the drivers front door which is a possibility.

cruisermark · May 4, 2018

I would get your Battery checked - a weak or failing Battery throws up all sorts of gremlins

Spacewagon52 · May 4, 2018

Thanks Colin, will try that fuse. Funny how the driver's door switch still works for the window but not the others? No idea where the fuse for the central locking might be?

6 minutes ago, cruisermark said:

I would get your battery checked - a weak or failing battery throws up all sorts of gremlins

Battery seems fine - starts - no labouring on turn-over.

I might wait for it to repair itself! LOL!

21 minutes ago, ColinBarber said:

Unlikely to be a fuse in the engine bay.

D FR Door is the drivers front door which is a possibility.

cruisermark · May 4, 2018

I would still not rule it out

ColinBarber · May 4, 2018

10 minutes ago, Spacewagon52 said:

Thanks Colin, will try that fuse. Funny how the driver's door switch still works for the window but not the others? No idea where the fuse for the central locking might be?

The central locking is controlled by the drivers door ECU, along with memory position for steering wheel parking etc.

Spacewagon52 · May 4, 2018

I will check all the fuses tomorrow. I changed the DFR Door fuse but no luck. Many thanks for the advice - will also put the Battery on charge - thanks Mark.

ColinBarber · May 4, 2018

If it isn't a fuse then it would be worth checking the connection on the drivers door switch panel hasn't come loose.

steve2006 · May 4, 2018

The only fuse common to all the failed items is labelled MPX-B rated at 10A and located in the interior fuse panel.

Spacewagon52 · May 5, 2018

11 hours ago, steve2006 said:

The only fuse common to all the failed items is labelled MPX-B rated at 10A and located in the interior fuse panel.

Thanks Steve! The MPX-B 10A fuse, on my Lexus, is located in the engine bay fuse box but it is fine!

My gut feeling is that the circuit board or the connection to the drivers panel switches have failed.

My next step is to take off the panel switch (with care!) to see if it is the connection as suggested by Colin. If that seems fine then it might be the door ECU - buy one from eBay and try it - around £30. Got to be worth a punt.

Thanks for the advice chaps! Will let you know how I get on!

Any tips for taking out the switch panel? Lever very carefully?

Spacewagon52 · May 5, 2018

IMPORTANT UPDATE GUYS!

MY LS400 HAS REPAIRED ITSELF!

No kidding! ALL WORKING!

THESE ARE JUST AMAZING CARS! PEEPS DON'T BELIEVE YOU!

To be honest I think Steve solved the problem when he said it was the MBX fuse. I took it out, tested it put it back but nothing seemed to work.

Went to take the key out of the ignition and the steering wheel moved! Central locking and all windows now work!

I am a little perplexed why it did not work straight away! Many thanks guys for all your advice! I was thinking about an expensive trip to Lexus in the end result.

Texas · May 5, 2018

When you charged your Battery did you dis-connect it from one or both of the cars main Battery connections?

if you did then this would of in effect done a 'soft' reset of any/all electronic components that contain volitile memory chips.

In the process of Removing the fuse mentioned this also done a 'reset' of any components fed via that fuse.

you can't beat a good old fashioned 'Turn it off and then turn it back on again' as a no tools no cost first action when things don't do what they are supposed to.

'Self Fixing'....never seen that in any brochure!

paul m.

Spacewagon52 · May 5, 2018

3 hours ago, Texas said:

When you charged your battery did you dis-connect it from one or both of the cars main battery connections?

if you did then this would of in effect done a 'soft' reset of any/all electronic components that contain volitile memory chips.

In the process of Removing the fuse mentioned this also done a 'reset' of any components fed via that fuse.

you can't beat a good old fashioned 'Turn it off and then turn it back on again' as a no tools no cost first action when things don't do what they are supposed to.

'Self Fixing'....never seen that in any brochure!

paul m.

Thanks Paul, it is a great relief. No I did not disconnect the Battery but interesting what you said about taking out the fuse, re-setting.

The "Self-Fixing" is only available on the LS 400 I am afraid!

Texas · May 5, 2018

The "Self-Fixing" is only available on the LS 400 I am afraid!

Shame..I can see that as a top selling point.

As for the Battery charging situation, I know it is a pita to physically remove batteries from cars ( manual handling with a glass back!) but if you do have reason to externally charge a car Battery then it is best to dis-connect the Earth/Negative connection ( unless you have insulated spanners of course) because if there is any slight current draw from the car ( ie interior lights or any after market permanently connected kit ie Dash Cam) then the Battery charger will interpret this demand as a demand for the Battery itself and up the charge level/rate which could do damage ( cook or boil ) to the Battery!

paul m.

Spacewagon52 · May 5, 2018

48 minutes ago, Texas said:

The "Self-Fixing" is only available on the LS 400 I am afraid!

Shame..I can see that as a top selling point.

As for the battery charging situation, I know it is a pita to physically remove batteries from cars ( manual handling with a glass back!) but if you do have reason to externally charge a car battery then it is best to dis-connect the Earth/Negative connection ( unless you have insulated spanners of course) because if there is any slight current draw from the car ( ie interior lights or any after market permanently connected kit ie Dash Cam) then the battery charger will interpret this demand as a demand for the battery itself and up the charge level/rate which could do damage ( cook or boil ) to the battery!

paul m.