ECU REMOVAL PANIC

runsgrateasanut · August 8, 2018

I have undone the lower three bolts on my 93 lexus but cannot see how to undo the top two. Steve 2006 write up on the glove box removal I followed yesterday, but ran into a snag. Firstly the G/box door differs slightly, and secondly there is a trap door for the Air bag (I'm assuming) which I am unsure if needs be poked through the hole of the liner before it can be withdrawn. Even attempting this I couldn't get movement of inner liner and also seems incredibly unusual if to change the glove box bulb at the back it would be necessary to go to such trouble.

Scotty Kilmer shows in his "replacing a bad ECU" him having removed the lower three screws and then the glove box drops down. But how did he undo the top two holding bolts? this is a mystery the video doesn't explain. I can see my ECU is situated on the lower panel rather than bolted in line with the Car. (I think.) Does the lower part just unplug with lever force between the G/B door and it? Is it just two push in clips? Hate breaking things. Thanks

runsgrateasanut · August 8, 2018

Work in progress update - found a bolt each side under the Felt liner of the box. Everything still feels pretty solid. Do I have to jemmy the below door downwards? More research needed. I'll go it alone.

runsgrateasanut · August 8, 2018

Its out - perseverence pays off.

steve2006 · August 8, 2018

Sorry only just seen your post, my tutorial was based on the Celsior which has no passenger airbag so slightly different procedure, good to hear you have managed to get it out though.

runsgrateasanut · August 10, 2018

Yes I worked it out in the end. Its now winging its way to the States to be (hopefully) rejuvenated with new Capacitors.

Not sometihng I planned on - having prepped a workplace over a six month period to do the job and about seven Soldering irons standing idle, but I have to say I bottled it, at the first fence. When my flexible friend didn't seem to want to loosen one side I thought this is not the time to practice my soldering skills. Looked in great shape on the outside of the Sandwich but didn't get to look within. Looked like virgin box. Almost felt it could be a replacement ,or perhaps they all look that good t'other side of the business parts?

Malc · August 10, 2018

it looks enormous .... is it ??

runsgrateasanut · August 10, 2018

9 x 7 inches guessing in old money. I was surprised how large it is. Wish I could tell date of manufacture but .........

steve2006 · August 10, 2018

If I knew you wanted it recapping I would have done it for you, I did 2 1994s last week for the same guy who has fitted the engine in his Land-cruiser.

This is my soldering station with fully variable temperature control and interchangeable tips.

runsgrateasanut · August 10, 2018

That looks the business as they say. Someone did mention your name two days ago Steve but I felt it would be unfair to ask any Member to do this job just in case it goes T's up.

I didn't want to trust Parcelforce with the ECU but they came in cheaper than others when found through Interparcel and not via Royal Mail.

I'm hopeful of a good outcome and will be worth the expense if the Car finally will go into Overdrive (I know it could be a solenoid problem) and has more grunt to get me up those long French Hills. It just doesn't seem to have the power I'd expect. This could I suppose be down to a blocked fuel filter. I have a replacement.

Twenty five years the Caps must be replaced so doing the examination backwards, perhaps.

As I have had no other problem with the Cars engine and it passed its Emissions, if the unit comes back as not repairable then I'd be shocked.

I didn't want a dead Car in the drive after a bungle on my part, especially after I've spent quite a lot on it and its grown on me over the last few years.

The 93 ECU's are rarer than Hen's teeth so they tell me so fingers crossed.

steve2006 · August 11, 2018

The Celsior ones are even rarer as there are subtle differences between them and the LS400 ones like no EGR system so I am fortunate to have a spare acquired many years ago. There was also an aftermarket ECU called MINES which 12 years ago could be bought for around £100.00 which are now fetching many times more in price.

Headlight covers, smoked and clear indicators were all cheap and available (I have a new set of clears if anyone wants them) but as the cars age parts are become more difficult to source.

From experience I know one of the suspect capacitors causes the engine revs to become limited to around 3000RPM which is probably the problem with yours, I take it the ECU has gone to LS Cowboy?

I am also hoping to be able to offer door accuator repairs on an exchange basis very soon which again is a very common fault on Lexus vehicles, just waiting for the parts to arrive for approval and quality.

runsgrateasanut · August 11, 2018

Some interesting info there Steve. Thanks.

Yes the ECU has gone to "The Man".

runsgrateasanut · August 15, 2018

Good news - I've heard back that there is no leakage in the 25 year old Capacitors.

Look forward to getting the ECU back and see how much of a difference to the drive.

Makes you wonder why some Caps leak and some don't. 139,500 mileage.

steve2006 · August 15, 2018

28 minutes ago, runsgrateasanut said:

Good news - I've heard back that there is no leakage in the 25 year old Capacitors.

Look forward to getting the ECU back and see how much of a difference to the drive.

Makes you wonder why some Caps leak and some don't. 139,500 mileage.

I could explain the effects of ESR on electrolytic capacitors but do you have the time 🙂

This type of capacitor contains paper and a liquid electrolyte ( hence the name),all this is encased inside an aluminium can and plugged at the base with a rubber bung to seal the contents inside.

As these components age the ESR ( Effective Series Resistance) increases....increased resistance produces more heat. heat increases the pressure inside and forces the liquid out at the weakest point (the bung) which being corrosive causes damage to the printed circuit board. The capacitor value also falls which then adds to the problems the ECU suffers from as a consequence.

Malc · August 16, 2018

Steve, is there a probable time-line / mileage at which we should all be looking to have our ECU's overhauled to ensure we remain trouble free ?

Thanks

Malc

steve2006 · August 16, 2018

These components do have a defined life span which is generally given in hours of use by the manufacturer so yes it would be a good idea to replace them before they reach that stage but this is difficult to define time wise unless you monitor how many hours the car has been driven.

Other factors also affect the lifespan like heat, humidity and vibration, the cooler the better....Lexus ECUs tend to be placed remotely which is good...the worse place where many are located is the engine bay.

As an example these components are used in the power supply of LCD televisions and a common failure is due to heat exposure which can happen with as little as 2 years use so 25 years proves the reliability and durability of the components used by Lexus.