Random Central locking behaviour!

[Matt1986]

Hi all. Had an odd situation with my 98 ls400 today. I went to unlock the car with the fob and it did nothing. Tried again and this time it only unlocked the rear passenger side door. Locked again and one more time tried to unlock. This time it only unlocked the front passenger side door. 

Also didn't work with the key in the door locks or boot. 

It's never done this before. Any thoughts on a probable cause? Could this be ECU related as mine needs the caps doing? 

Thanks. Matt 

[cruisermark]

Hi matt - How old is the Battery? - I would check that first

[Matt1986]

Not sure on the Battery but just to update this a little. My wife was having this issue whilst at work. I've now seen the car and cannot get the central locking to operate at all. It also seems that the seat memory buttons and automatic retraction of the steering wheel have all stopped. The seats and wheel can be moved manually but won't move on auto.Can't open either back door and there's no key. What do all these parts have in common? It also set the alarm off when I started it up but it started and ran fine. The alarm.stopped after about 30 seconds. 

I feel this is going to be hard and expensive to resolve. 

[steve2006]

Having looked through the electrical manual the common factor would seem to be the Body ECU as all three problems are associated with this device. I would start by disconnecting the Battery negative terminal for a short period of time ( if your radio has a code make sure you know it) and then reconnect the Battery terminal to see if this resets the ECU.There are no fuses common to all three systems.

[Matt1986]

54 minutes ago, steve2006 said:

Having looked through the electrical manual the common factor would seem to be the Body ECU as all three problems are associated with this device. I would start by disconnecting the battery negative terminal for a short period of time ( if your radio has a code make sure you know it) and then reconnect the battery terminal to see if this resets the ECU.There are no fuses common to all three systems.

Yes I'm coming to the same conclusion. Seems odd that it's just stopped working all of a sudden. Do you know where the body unit is located? 

 

Thanks for all your help and looking this up for me Steve 🙂

[Matt1986]

So just to wrap up this issue I did as steve2006 recommended and disconnected the negative Battery terminal for a couple of minutes and reconnected it. This seemed to solve the issue and now everything is working ok. Just needed a reset.

Thanks for the tip steve2006. 🙂

[steve2006]

You’re welcome.....if it don’t work try switching it off and back on first 🙂

 

[dendonc]

12 hours ago, Matt1986 said:

Just needed a reset

Do you mean reset the codes? if so is the alarm going off when you try to start it?

[Matt1986]

2 hours ago, dendonc said:

Do you mean reset the codes? if so is the alarm going off when you try to start it?

No I literally just disconnected the negative Battery terminal for a few minutes and reconnected again. After that it all worked fine.