ECU damage, what can cause it?

ubercal said:
Ok so it looks like the problem might be a part that has an effect on the ecu.eg the maf sensor or 02 sensor might be cock eyed , or you have an air leak.This would cause the car to run lean and det , or maybe go into limp mode.
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02 sensor, is missing, as the exhaust is different, other 02 sensor is got a heater element not working (maybe that might cause this).
maf sensor was checked, air leak checked ,

nothing awry with any of those.

do any of you guys know good mechanics i should be visiting to confirm all these things? especially in JHB area.
now that we have isolated it to a electrical issue specifically a ECU/computerbox/wiring loom issue?
 
eg2505 said:
02 sensor, is missing, as the exhaust is different, other 02 sensor is got a heater element not working (maybe that might cause this).
maf sensor was checked, air leak checked ,

nothing awry with any of those.

do any of you guys know good mechanics i should be visiting to confirm all these things? especially in JHB area.
now that we have isolated it to a electrical issue specifically a ECU/computerbox/wiring loom issue?
Click to expand...

well that is a big problem.car needs an 02 sensor for your afr(air fuel ratio)
 
depends which 02 sensor it is.you get the front and rear.i know with my car both need to be working else it starts running badly.
 
if you dont get your 02 sensors sorted iam sure your engine will blow up due to your car running lean.
 
eg2505 said:
it has the one, except that one has a problem with the heater element
the other is missing due to the exhaust being replaced.
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The ECU depends completely on the inputs it gets from the sensors in order to make adjustments to air/fuel etc.
I would start there.
 
thinking about it , your car not starting or giving intermittent issues is the ecu going into limp mode to protect your engine from failure.
 
So the question is when did your car actually start giving problems , was it after you had the exhaust changed ? This could give us good clues
 
ubercal said:
So the question is when did your car actually start giving problems , was it after you had the exhaust changed ? This could give us good clues
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many many months after the exhaust was originally replaced,

I get a voltage from the o2 sensor on my app, its just the heater element that damaged. mechanic said its only used when its cold,
right now, its 30 odd degrees, still same error code,
other o2 sensor is missing inside the exhaust, thats obviously missing. (apparently the car can work perfectly without this)

worked perfectly up to now, engine light is off,

believe me, we have had so many "experts" in electrical and computer problems, and a family member who is a expert as well,

test everything with a voltmeter, and checked with a few different scan tools, that NOBODY can understand how the ECU Blows up constantly.
even the boffins locally at auto ECU, who are the nationwide experts in this sort of thing cant understand it, its confusing even the most experienced guys.

I can promise you 90% of the things you asking have been checked and rechecked numerous times,,

its simply designed badly, and built to strand you out on the road,.

so here is what im going to do, fix it temporarily, and get rid of this POS ASAP so I dont have to suffer anymore with it.

if you guys know somebody who I can take it to who will diagnose and fix this issue right, I'm prepared to do that.
 
ubercal said:
if you dont get your 02 sensors sorted iam sure your engine will blow up due to your car running lean.
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The ECU will pick up that the EGO sensor is dead/missing and use the preset rich mix. EGO is only used to trim the mix leaner. So it will run rich and not lean and just be less economic. If the car has to conform to modern EU emission regulations, it will also go into limp mode, as you will not make emmision regulations without an EGO sensor.
 
Does the car keep running when you start it on spray? Or does it die? (Also, go buy some faststart/easystart at a Midas, deodorant is probably not good for it)
Starting on spray usually means a fuel issue, although it could be spark. Sounds like the injectors aren't firing properly.

Is the only problem the not starting? So once you are on your way, it's fine? Sorry if this is answered, I missed it over, so please remind.

The O2/Lamda heater is because the Sensor itself doesn't work properly when cold. It will eventually heat up from exhaust, but usually not hot enough (it should be way hotter).
So that could cause an issue. You should be fine without the other sensor, as it's presumably the one after the cat, although you are probably less efficient and could be killing the cat quicker.

ECUs are exceptionally reliable usually, which is why they get glued together, because they aren't serviceable, and you should never have to.
And given that no one seems to have had this problem other than you, you seem to have some shocking luck. It also means something external is wrong.
But if you've still got the previously dead ones, get someone to open up and look for component damage I guess. If they are dead, it won't matter if you break them more, and it should be possible to tell electrical damage vs opening damage.
 
thanks @Binnacle,

I agree , nobody can understand how it is that the ECU keeps breaking,
but this keeps happening to me, many many times after fixing it up and getting it to work properly.

what we have deduced, is this, if you connect a thermocouple, to the ECU, and try to start when the ECU is cold, about 19-21 degrees,
wont start.

but if you heat physically the ECU (with a hairdryer) to about 27-30 degrees, will start perfectly, like nothing ever happened.

what I do know, is the o2 sensors might need replacing, but the mechanic/electrician checked it.
checked, the crank angle sensor as well, and even replaced the battery,

only other thing that might cause all this hassles is a wiring issue, as the wiring might be shorted somewhere deep inside the harness.

but Im not sure if this can even be fixed?
 
eg2505 said:
thanks @Binnacle,

I agree , nobody can understand how it is that the ECU keeps breaking,
but this keeps happening to me, many many times after fixing it up and getting it to work properly.

what we have deduced, is this, if you connect a thermocouple, to the ECU, and try to start when the ECU is cold, about 19-21 degrees,
wont start.

but if you heat physically the ECU (with a hairdryer) to about 27-30 degrees, will start perfectly, like nothing ever happened.

what I do know, is the o2 sensors might need replacing, but the mechanic/electrician checked it.
checked, the crank angle sensor as well, and even replaced the battery,

only other thing that might cause all this hassles is a wiring issue, as the wiring might be shorted somewhere deep inside the harness.

but Im not sure if this can even be fixed?
Click to expand...
It could be an earth fault not necessarily a short, shorts are seldom intermittent, most of the time it is ether a short or it isn't.
 
thechamp said:
It could be an earth fault not necessarily a short, shorts are seldom intermittent, most of the time it is ether a short or it isn't.
Click to expand...

thought that as well, was pointed out that my earth strap was laying loose, did connect it, and still issues.
so what else could it be? wiring issues inside the injector harness? damaged injector?

is there actually a way to know whats damaged?
 
eg2505 said:
thought that as well, was pointed out that my earth strap was laying loose, did connect it, and still issues.
so what else could it be? wiring issues inside the injector harness? damaged injector?

is there actually a way to know whats damaged?
Click to expand...
There are many earth connections on a car, over time corrosion sets in which can cause many problems, having said that it does look you have many issues on the car, was the ECUs ever tested by an indepedent party or did the dealership do their usual replace and let's see if it comes right?
 
thechamp said:
There are many earth connections on a car, over time corrosion sets in which can cause many problems, having said that it does look you have many issues on the car, was the ECUs ever tested by an indepedent party or did the dealership do their usual replace and let's see if it comes right?
Click to expand...

was tested many times by a ECU specialist, (independent), and was tested by another (contracted) specialist to Kia HQ in SA,
checked many times my earth leakage, and cheeked many times my alternator wiring, to try determine the fault here.

haven had any luck in finding out what is he issue here, looked and looked but nobody can figure out what is the root cause here.
 
Wait for a hot day. And trade it in. Get rid of it. Do not keep it. Do not waste time and money trying to fix it. Do not think about how nice it sometimes is. Do not get tempted to keep it a bit longer. Don’t believe that you have to keep it to get your money’s worth from all the repairs you’ve already paid for. Don’t throw good money after bad. Don’t see fixing it as a challenge that you can’t resist and that will somehow make you a better man if you do get it right.

GET RID OF IT!
 
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