Where the ECU is located? IS300H

[Prejsnatan]

Hi any idea guys where can I find the ECU in my Lexus IS300H? 

Thanks 

[Andrew888]

Engine bay I believe on the right hand side next to the fuse/relay box

[Britprius]

It depends on which ECU you are thinking of. Although in later Toyota/Lexus hybrids some ECU's have been combined there is more than one. To give some idea my Prius had 28 ECU's.

John. 

[Mr Vlad]

Is that a miss type John? 28 ECU''s? 

[ColinBarber]

9 hours ago, Mr Vlad said:

Is that a miss type John? 28 ECU''s? 

sounds about right.

You obviously have the main engine/transmission ECU which is the one most people mean when they just state ECU but almost every other system has its own ECU. e.g. there is one for each door windows and power locks), tyre pressure warning ecu , reversing sensor ecu, skid control ecu, steering wheel tilt/reach ecu, shift lock control ecu, cooling fan ecu, power management control ecu etc. etc.

[Mr Vlad]

Mmmmmmmm interesting Colin. In my 45 years of car ownership and having fiddled with all of them and have pro mechanic friends I've never heard till now that each electric system has its own ECU. The most general use of ECU is purely for the Engine Control Unit. Any other use is surly egotistical or similar. I must admit I've had a laugh at the number of ECU''s some folk think there are.

Each to their own 

[Britprius]

1 minute ago, Mr Vlad said:

Mmmmmmmm interesting Colin. In my 45 years of car ownership and having fiddled with all of them and have pro mechanic friends I've never heard till now that each electric system has its own ECU. The most general use of ECU is purely for the Engine Control Unit. Any other use is surly egotistical or similar. I must admit I've had a laugh at the number of ECU''s some folk think there are.

Each to their own 

There is even an ECU to control how all the ECU's communicate with each other. It is called a gateway ECU.

John.

[Britprius]

The term ECU is for "electronic control unit", and is often wrongly used as "engine control unit" when even the older basic control units had other systems such as security built in to one unit.
To days vehicles are getting increasingly more complex. Going back not to many years ago cars had maybe 3 electric motors. A starter motor, a heater fan, and a wiper motor. Today the list runs into 100 or more. Don't believe me start counting.

John.

[Martin F]

1 hour ago, Britprius said:

The term ECU is for "electronic control unit", and is often wrongly used as "engine control unit" when even the older basic control units had other systems such as security built in to one unit.

This is correct, and exactly where the confusion occurs. 

An ECU controlling an engine is highly complex and has a lot of computational power, whereas an ECU controlling the central locking is less complex and many years ago didn't even have a CPU in it but was still referred to as an Electronic Control Unit. 

[Guest]

3 hours ago, Mr Vlad said:

Mmmmmmmm interesting Colin. In my 45 years of car ownership and having fiddled with all of them and have pro mechanic friends I've never heard till now that each electric system has its own ECU. The most general use of ECU is purely for the Engine Control Unit. Any other use is surly egotistical or similar. I must admit I've had a laugh at the number of ECU''s some folk think there are.

Each to their own 

https://www.csselectronics.com/screen/page/simple-intro-to-can-bus/language/en

Have a watch. 

 

[Mr Vlad]

Sorted and way over my head nowadays.