Location of the Body ECU in a 2012 Avensis (Petrol)

[FatOldBloke]

Hi All

Does anybody know the location of the body ECU on a 2012 Avensis.  The cental locking is intermittent and I need to sort it out (referb) - the dealer quoted £880 for a new one :).

I have searched the net and it seems it is integrated with the fuse box.

Any help will be appreciated.

Bren

 

[avetoy]

Fuse box diagram for Avensis:

2009-2017 Toyota Avensis (T270) Fuse Box Diagram » Fuse Diagram.pdf

[furtula]

What are the exact symptoms you have?

[FatOldBloke]

1 hour ago, avetoy said:

Fuse box diagram for Avensis:

2009-2017 Toyota Avensis (T270) Fuse Box Diagram » Fuse Diagram.pdf 616.62 kB · 4 downloads

Many thanks for the diagram JJ it is a big help.  The fuse box and main body ECU are one unit - perfect.  Assuming the main dealer's diagnosis is correct.

Regards

Bren

[FatOldBloke]

Hi Dean

The fault is intermittent operation of the central locking system that results in only the driver's door key operating.  None of the other doors will open even from inside the car.  This is my wife's car so if I am locked in the passenger seat.........  The fault is very intermittent but very annoying.  If you have any other ideas I appreciate them.

The dealer diagnosed a replacement main body ECU to fix it - so I have found somebody breaking on so will give it a go.

Cheers

Bren

[avetoy]

Have you tried the easiest: take car´s Battery cable off and put it back after few minutes?

Does this car have the feature that doors lock automatically when speed rises over 6 km/h? 

[FatOldBloke]

54 minutes ago, avetoy said:

Have you tried the easiest: take car´s battery cable off and put it back after few minutes?

Does this car have the feature that doors lock automatically when speed rises over 6 km/h? 

Hi JJ

I have not tried anything - however the dealer will have (I hope :)). The challenge is taking the power off the system will probably reset everything and it will run for a few weeks and then fail again.  I am an electronics engineer - this sort of fault is usually caused by one of the passive components like a capacitor leaking or becoming heat sensitive.  The usual fix is to replace them.  Also to test the unit will require some ATE (automatic test equipment).

The car does auto-lock its doors because it unlocks them when you put it in neutral at a RAB - it is an auto.

If I can source a unit from a scrapper I will send the old one off for refurb - it is possible and old unit will show the same fault.  It would be useful to know if the unit is common to the diesel version of the car and how many other people have seen the problem

Any good ideas are very welcome.  If the car is exhibiting the fault when I get home at the weekend I will take off the Battery lead.

Thanks

Bren

[furtula]

The dealers dont fix things, they just replace stuff until the problem goes away, at the expensatte of your wallet.

If you suspect faulty components, then cheapest option is to replace the component yourself. I had power steering die on me a month ago, i replaced the ECM for it, worked fine, the computer showed faulty relay, which when tested was fine, but then again a lot of people said they just disconnected this from the harness, reconnect few minutes later and worked fine for them ( Battery removal does not help).

If you go to http://japan-parts.eu and enter your vin, you can locate the correct part number, send this to few breakers, and see the pricing.

You might have to re-code the keys later, since it's a different unit,a Toyota techstream cable would be helpful there, and it's quite cheap to get one online, also software is free.

[avetoy]

15 hours ago, FatOldBloke said:

 

... this sort of fault is usually caused by one of the passive components like a capacitor leaking or becoming heat sensitive ...

 

That´s right, the capacitor problems are very common in many electrical devices. Cheap components, poor quality...

Somebody might say they are used deliberately...

Anyway I hope you´ll find used unit from scrapper. I´m not sure but probably there is no difference between diesel and petrol cars in this case. It wouldn´t make sense if there is?

 

17 minutes ago, furtula said:

The dealers dont fix things, they just replace stuff until the problem goes away, at the expensatte of your wallet.

Sad but true...

[furtula]

There is no difference if the module is from petrol or diesel, if the part number is correct.

The electronics they use in modules are quite beefy, but when you replace few components with 10x more for doing the same job, well the risk of something dying on you also increases.

I would not say they use cheap components, when i took apart my steering module, that thing was beefy, and really nicely built, huge heatsinks, the components were mostly Japanese made, all coated in lacquer to prevent possible rusting of contacts.

That's what i hate about modern cars, they replace things that work fine, with electronics, giving you more potential points of failure. If i was not living in a place with a lot of salt on the roads and rust was not such a big issue, i'd be driving a 2002 car.

[FatOldBloke]

2 hours ago, furtula said:

The dealers dont fix things, they just replace stuff until the problem goes away, at the expensatte of your wallet.

If you suspect faulty components, then cheapest option is to replace the component yourself. I had power steering die on me a month ago, i replaced the ECM for it, worked fine, the computer showed faulty relay, which when tested was fine, but then again a lot of people said they just disconnected this from the harness, reconnect few minutes later and worked fine for them ( battery removal does not help).

If you go to http://japan-parts.eu and enter your vin, you can locate the correct part number, send this to few breakers, and see the pricing.

You might have to re-code the keys later, since it's a different unit,a Toyota techstream cable would be helpful there, and it's quite cheap to get one online, also software is free.

Thanks Dean the key coding will be the next hurdle.  I think I have a techsteam cable from when I owned a LS430.

[mrfixer]

If you can afford to have the car laid up for a few days you might want to send the unit to one of the ECU repairers (e.g. BBA Reman, ECUtesting etc). Might be a relatively cheap fix and no coding required.

[Konrad C]

On 6/3/2019 at 3:15 PM, FatOldBloke said:

Hi JJ

I have not tried anything - however the dealer will have (I hope :)). The challenge is taking the power off the system will probably reset everything and it will run for a few weeks and then fail again.  I am an electronics engineer - this sort of fault is usually caused by one of the passive components like a capacitor leaking or becoming heat sensitive.  The usual fix is to replace them.  Also to test the unit will require some ATE (automatic test equipment).

The car does auto-lock its doors because it unlocks them when you put it in neutral at a RAB - it is an auto.

If I can source a unit from a scrapper I will send the old one off for refurb - it is possible and old unit will show the same fault.  It would be useful to know if the unit is common to the diesel version of the car and how many other people have seen the problem

Any good ideas are very welcome.  If the car is exhibiting the fault when I get home at the weekend I will take off the battery lead.

Thanks

Bren

The auto lock feature can be disabled. It should be in your owner's manual if you have it. I would disable the auto lock feature and see if the issue persists, before doing any extra work and spending money. The auto lock has a mode which keeps the passenger doors locked, until the driver has press the door lock switch on the drivers door. 

This post may help.