Car ECU, replace or repair

[amyk]

Many cars have it under the bonnet, usually beside the engine.

[Simon]

Many cars have it under the bonnet, usually beside the engine.

pretty stupid place, haven't forgotten when my dads escort engine flooded because we ran into deep water the ecu would have gone with it, we dried the engine out but an ecu would not have come out well.

[SeanB]

My ECU is on the top side of the engine, if it is flooded the entire engine is full of water.........

If you do get another ECU you will need the keys as well, as they have a transponder that is interrogated by the ECU at power up and randomly thereafter. No match no go, unless you leave the power on for 4 hours, when the ECU will go into limp home mode and ignore the key transponder code.

[aluck]

Piratebay is blocked in the uk

No problem here, pal. Check your P.M.

I can try to find the diagram for your car, but I need the exact year and model, including engine type (i.e. 1.25 16V DHD).

Possible causes for that fault:
 - you have more than one temp sensor, one for dash and one for ECU
 - you have just one temp sensor; good wiring between dash and sensor, but bad wiring between ECU and sensor
 - faulty ECU (seen that, been there)

Give me your model and we will try to find out about sensors.

[Simon]

Fiesta finesse, 2000 Endura E engine.

[aluck]

Fiesta finesse, 2000 Endura E engine.

Is it 1.3 or 1.4 liter model? 1.4 is 16 valve. And what about horsepower?

There's a dozen of those engines, sorry...

[Simon]

1.3L I think 60 BHP

[aluck]

1.3L I think 60 BHP

Then it's J4L or J4J engine. Please P.M. your e-mail address - I've got the wiring diagrams for your car.

[aluck]

Here's a short troubleshooting guide:
 - turn ignition on
 - check the voltage between battery ground and pin 46 of ECU connector. it should be 0 V
 - check the voltage between battery ground and pin 7 of ECU connector at room temp (20?). it should be 2.9-3.1 V
 - check the voltage between battery ground and pin 7 of ECU connector at 80?. it should be 0.7-0.9 V
 - let as know of the result

[aluck]

pretty stupid place, haven't forgotten when my dads escort engine flooded because we ran into deep water the ecu would have gone with it, we dried the engine out but an ecu would not have come out well.

that's why 80% of Russian-made vehicles have ECUs inside the cabin, under passenger's feet.

doesn't help much, though.

[SeanB]

Russian vehicles, built cheap and easy to repair. Really good heaters though...... Add as well a rear window demister, so your hands don't get cold pushing it.....

[aluck]

Russian vehicles, built cheap and easy to repair. Really good heaters though...... Add as well a rear window demister, so your hands don't get cold pushing it.....

The only one I really like is Lada 4x4 http://en.wikipedia.org/wiki/Lada_4x4
It's a real beast when offroad. And it's a pain in the butt on the road.

[IanB]

All this reinforcement of "Found On Road Dead" or "Fix Or Repair Daily" is depressing. May I suggest your next car is a Honda?

[SeanB]

I have had a Ford, very nice vehicle and easy to fix. Only time it died on the road I had a spare ignition module ready, known failure, and it was a pirate one anyway, so I had bought 2 for $5 anyhow..

[aluck]

May I suggest your next car is a Honda?

Why not Subaru? Those beasts are insanely reliable. A friend of mine has Honda CR-V, and his wife has Subaru Forester. They live in a desert area, so just one failure can cost you a lot by means of your health and life. He literally calls her car "an ass-saviour".

[Zad]

Given the number of people I know who have had big problems with recently made Japanese cars, I wouldn't touch them with a bargepole. Much of the reputation of these companies is down to skewed reliability data as they tend to be self-reported in voluntary surveys. What it usually boils down to, is that cars used by retired people who don't drive much are apparently really reliable, and cars used every day to drive across fields are unreliable. Who knew?

[WorldPowerLabs]

All this reinforcement of "Found On Road Dead" or "Fix Or Repair Daily" is depressing. May I suggest your next car is a Honda?

I own a Ford and a Lexus (Toyota).  My wife owns a Honda.  All are from the late 1990s.  All have been reliable and mostly trouble-free.  Ford is at ~140k miles, Lexus is around 116k, Honda is almost 200k.  OEM Parts for the Ford and Honda are pretty inexpensive.  Lexus parts are very expensive, though a better deal can be had by finding the Toyota equivalent.  Both Ford and Honda have lots of aftermarket repair parts -- Lexus, not so much.  The Lexus has had far fewer annoying problems than the other two (except for the stereo -- even with the Nakamichi option, the speakers are crap).  The Ford has structural rust; the Lexus and Honda do not.  The paint on the Ford is peeling off of the primer (yes, it is the original paint).  The clearcoat on the Honda is failing.

None of the vehicles requires than $1000/year on average for repair and maintenance, so I'd say that they all do pretty well in that respect.

I used to have a Nisssan.  That car was great, except for rust!  Had one failed starter -- and no other major mechanical issues in 14 years and 198,000 miles.

This reminds me of some jokes:

What do you call 6 Chevys and a Ford?  A junkyard and a ride home!
Nine out of 10 Chevys made in the last 10 years are still on the road.  The rest made it home.

[jucole]

I would think the ECU is the least likely place to look for a fault. It is solid state electronics with no moving parts. There is nothing to go wrong.

A few years ago I had to use a pic 16f84a to replace the entire indicator system in a Peugeot 206 because of a failed blackbox. I was so angry with the rip-off price of a new box and the fact that there was no documentation that i was determined to make it work. I bypassed the box for the left, right and hazzard switches, then wrote some code to handle the logic; It worked a treat!  You could potentially replace the blackbox and the ecu given enough time and effort. It was certainly not worth it for my crappy 206 though but if you had a nice car you might fancy it.

[aluck]

You could potentially replace the blackbox and the ecu given enough time and effort.

It's not that simple. There are several Russian wizards who make custom-made firmwares for ECUs. It's rather expensive because of all the equipment they use. And it's very complicated, because there is still no reliable scientific model for internal combustion engine. At least half of the parameters in the ECU are not calculated, they are based on experiments on the exact engine. I know several guys who make so-called "chip-tuning". Basically, what they are doing, is they take your car and your ECU and try to get better parameters for ECU firmware. Sometimes they replace the firmware completely. One could get 20-30 hp more after that procedure.

[jucole]

You could potentially replace the blackbox and the ecu given enough time and effort.

It's not that simple.

My crappy Peugeot 206 1.9 D LX, 2000 year plate was pretty simple as there wasn't much to it, a few sensors etc.  I got a ecu and blackbox from a scrap yard and ebay for next to nothing and ripped them apart to study them and did a lot of research, but like I say mine was a simple car,  but from what you say it appears it's more difficult for more complex systems, the biggest problem for me was lack of documentation.

[Mechatrommer]

if you already have the schematic and yet still unable to figure out whats going on, i suggest bypassing the fan and temp sensor and make your own FCU (fan controller unit). btw, does anybody know or have ECU schematics for toyota wish car 1.8cc 2003 make?

[aluck]

btw, does anybody know or have ECU schematics for toyota wish car 1.8cc 2003 make?

ECU schematics? You are dreaming.

[jucole]

Many cars have it under the bonnet, usually beside the engine.

In the Peugeot 206 I looked at, there was an ECU (blackbox) by the engine and another blackbox under the steering column. The later Blackbox handled all the non-engine related stuff, including the fan, display, light, indicators, odb etc

[Mechatrommer]

btw, does anybody know or have ECU schematics for toyota wish car 1.8cc 2003 make?

ECU schematics? You are dreaming.

coz i wonder, if i translated it correctly i read people have their car's ecu schematics (fan controller section) in early page. (i havent read all pages through)

[aluck]

ECU schematics? You are dreaming.

coz i wonder, if i translated it correctly i read people have their car's ecu schematics (fan controller section) in early page.

Nope. It's vehicle wiring. What's inside ECU - is a well-kept secret. Never seen a full schematics, although there's nothing hi-tech.

Some manufacturers even go so far that they order ICs with their's own markings. And instead of original IC name like NE555 you will get something weird like J25. Good luck seeking a datasheet.