How often does an ECU write a car off?

How often does an ECU write a car off?

Author
Discussion

Triumph Man

8,670 posts

167 months

Thursday 27th February 2020
quotequote all
Riley Blue said:
bristolracer said:
Lot of ECUs get written off by water, blocked drain holes,convertibles with dodgy seals, leaking windscreens.

For some reason car makers seem fond of putting them under areas where water gathers or in the bottom of cavities where water will track into
yes Who in their right mind would build a luxury saloon with inadequate plenum chamber drainage then place much of the car's electronic gubbins in the passenger footwell, the place where any water build-up runs into?

Audi, that's who.
Don't forget that the brake servo is also situated in this "trough" and if the water level gets to a certain point can get ingested through the vacuum hose and hydrolock the engine. This, I suspect is a diversionary tactic so that owner is no longer worried about the electronics, rather his 6 bent conrods!

Poshbury

683 posts

118 months

Thursday 27th February 2020
quotequote all
Riley Blue said:
bristolracer said:
Lot of ECUs get written off by water, blocked drain holes,convertibles with dodgy seals, leaking windscreens.

For some reason car makers seem fond of putting them under areas where water gathers or in the bottom of cavities where water will track into
yes Who in their right mind would build a luxury saloon with inadequate plenum chamber drainage then place much of the car's electronic gubbins in the passenger footwell, the place where any water build-up runs into?

Audi, that's who.
Bentley too as a few GT owners have found out to their cost.

2Btoo

3,410 posts

202 months

Thursday 27th February 2020
quotequote all
Triumph Man said:
Riley Blue said:
bristolracer said:
Lot of ECUs get written off by water, blocked drain holes,convertibles with dodgy seals, leaking windscreens.

For some reason car makers seem fond of putting them under areas where water gathers or in the bottom of cavities where water will track into
yes Who in their right mind would build a luxury saloon with inadequate plenum chamber drainage then place much of the car's electronic gubbins in the passenger footwell, the place where any water build-up runs into?

Audi, that's who.
Don't forget that the brake servo is also situated in this "trough" and if the water level gets to a certain point can get ingested through the vacuum hose and hydrolock the engine. This, I suspect is a diversionary tactic so that owner is no longer worried about the electronics, rather his 6 bentconrods!
More likely to be four bent conrods. The vast majority of Audis are poverty-spec 4-pot things, bought for the 'bling'.

GroundZero

2,085 posts

53 months

Thursday 27th February 2020
quotequote all
I know little about car ECUs, so forgive this next question.
How hard is it to simply go to the scrap yard and take an ECU out of an equivalent car to replace one that is broken in your own?


Nickbrapp

5,277 posts

129 months

Thursday 27th February 2020
quotequote all
2Btoo said:
More likely to be four bent conrods. The vast majority of Audis are poverty-spec 4-pot things, bought for the 'bling'.
Christ alive what is it about this website that attracts these sort of cretins

Richard-D

751 posts

63 months

Thursday 27th February 2020
quotequote all
Impossible to tell how many are genuinely written off by ECU failures. So many garages will declare the ECU has failed when changing the component related to the OBD fault hasn't cured it. That's what they think 'fault diagnosis' is.

J4CKO

41,287 posts

199 months

Thursday 27th February 2020
quotequote all
Nickbrapp said:
2Btoo said:
More likely to be four bent conrods. The vast majority of Audis are poverty-spec 4-pot things, bought for the 'bling'.
Christ alive what is it about this website that attracts these sort of cretins
Indeed, amazing how so many folks choices get looked down upon.

An Audi isnt generally a cheap thing to have, be it via finance or buying outright.

It always amazes me how people are so quick to slag stuff off, any four pot Audi is a decent enough car, and for a lot of people its something to aspire to, no such thing as a "Poverty Spec" one by and large as they all have pretty much all the stuff you could need nowadays.



Krikkit

26,500 posts

180 months

Thursday 27th February 2020
quotequote all
GroundZero said:
I know little about car ECUs, so forgive this next question.
How hard is it to simply go to the scrap yard and take an ECU out of an equivalent car to replace one that is broken in your own?
It can range from very simple to immensely complex, depending on the manufacturer and age of the vehicle.

Sometimes it's a case of swapping a set of ECUs rather than just one, as they can be coded to operate together, and swapped together too.

e.g. An old Saxo/106 - swap the ECU and the key over for the immobiliser and away you go. Clio 1x2 you can swap the ECU and body control unit + key immobilisers and they play fine. Older BMWs you can swap single units but they will need recoding (which is often quite simple).

gooner1

10,223 posts

178 months

Thursday 27th February 2020
quotequote all
Krikkit said:
GroundZero said:
I know little about car ECUs, so forgive this next question.
How hard is it to simply go to the scrap yard and take an ECU out of an equivalent car to replace one that is broken in your own?
It can range from very simple to immensely complex, depending on the manufacturer and age of the vehicle.

Sometimes it's a case of swapping a set of ECUs rather than just one, as they can be coded to operate together, and swapped together too.

e.g. An old Saxo/106 - swap the ECU and the key over for the immobiliser and away you go. Clio 1x2 you can swap the ECU and body control unit + key immobilisers and they play fine. Older BMWs you can swap single units but they will need recoding (which is often quite simple).
.


I'm presently awaiting the return of my 1994 e36 325i ecu from a company that charges £30 for testing, and £125 for repairing most ecu's. Due to the ridiculous placing by bmw of the item this will be the 2nd time in 4 years this car has suffered ecu failure. 1st time round I just swapped in a 2nd hand one from the same year & spec car, cost £60 so not too painful. Cost of the same replacement item has now absolutely rocketed for a 2nd hand ECU with no testing or part replacements at all. People , imo, give up too easily when their cars develop faults, though I do understand why tbf"

2Btoo

3,410 posts

202 months

Thursday 27th February 2020
quotequote all
J4CKO said:
Nickbrapp said:
2Btoo said:
More likely to be four bent conrods. The vast majority of Audis are poverty-spec 4-pot things, bought for the 'bling'.
Christ alive what is it about this website that attracts these sort of cretins
Indeed, amazing how so many folks choices get looked down upon.

An Audi isnt generally a cheap thing to have, be it via finance or buying outright.

It always amazes me how people are so quick to slag stuff off, any four pot Audi is a decent enough car, and for a lot of people its something to aspire to, no such thing as a "Poverty Spec" one by and large as they all have pretty much all the stuff you could need nowadays.
Apologies folks, I didn't intend a flow of opprobrium. Just saying things as I see them!

Back to ECU's ... the vast majority of 'ECU Failures' that I have ever come across are actually either sensor failures or wiring failures. When ECU's are kept dry and free of vibration they very rarely fail (although ancillary components like capacitors sometimes do). However sensors are usually cheaply made and in harsh environments and more prone to failure, as is wiring and connectors. A lazy garage will all to readily diagnose electrical issues as 'ECU Failure' and get no further when in reality the ECU is fine, it's just not getting the signals it should have.

treeroy

564 posts

84 months

Thursday 27th February 2020
quotequote all
My Fiat Panda's ECU "wrote the car off" a few months ago.

swampy442

1,472 posts

210 months

Thursday 27th February 2020
quotequote all
Riley Blue said:
bristolracer said:
Lot of ECUs get written off by water, blocked drain holes,convertibles with dodgy seals, leaking windscreens.

For some reason car makers seem fond of putting them under areas where water gathers or in the bottom of cavities where water will track into
yes Who in their right mind would build a luxury saloon with inadequate plenum chamber drainage then place much of the car's electronic gubbins in the passenger footwell, the place where any water build-up runs into?

Audi, that's who.
Look at Mondeo's, in front of the front wheel!

swampy442

1,472 posts

210 months

Thursday 27th February 2020
quotequote all
Scootersp said:
I had my 2001 Volvo CEM repaired before it was 15 years old, I think it was relatively common as the guy in London that repaired it had a business just for that.
I wish I'd known that, sold a C30 for scrap late last year because of total ECU failure

Jamescrs

4,450 posts

64 months

Thursday 27th February 2020
quotequote all
When I owned a Mk2 Ford Focus ST I was doing some map testing and data logging work with one of the well known Ford tuners and I think we had three different ECU's we were swapping between each other with different maps and variables on, when there was a new version of the map to try and used to drive to their premises, they gave me an ECU and I'd change it myself in 5-10 minutes and give them the other back to be tweaked. It was actually quicker than loading new maps straight to the ECU each time.

lufbramatt

5,318 posts

133 months

Thursday 27th February 2020
quotequote all
I've got a 2013 Honda that fried it's ECU just before Christmas, apparently one of the injectors burnt out and took out the driver circuit in the ECU. Main dealer wanted £1750 for a new ECU, an injector and labour for coding it all. Gulp.

To be fair to them they did source a 2nd hand ECU instead to keep costs down which knocked over a grand off the bill. So wasn't the end of the world and nowhere close to writing the car off. I probably could have got it fixed cheaper using specialists and sourcing parts myself but couldn't be bothered with the hassle.