sounds expensive part 2, rover 75 cdt 02

[Departed]

Originally Posted by bl52krz

have you thought of trying a bmw dealer?

Not for parts inside the ECU. They may supply a complete new ECU but that's silly money.

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Originally Posted by lowedb

I didn't have a camera, but I've worked in Automotive electronics for many years and never seen anything quite the same.

They are marked 15uF, 100V. Generally you'd expect them to be electrolytics with those ratings, but they looked more like polyesters. Rectangular (25 long, 8 wide, 12 high at a guess from memory) but most unusually, 4 legs. No polarity marking.

I'm assuming those are the ones, as all the other caps were rated 50v or less, and there were three of one and one of the other.

Update: searching on RS's website, I've at least identified the manufacturers symbol. The manufacturer is EPCOS. RS stock ones with the right rating, though not with 4 pins.

It's late now (no not really, but the glass of wine is kicking in) so I'll continue the research later as you need a clear head to find this detail.

[Timbo.P6]

what a lovely man

[BigRuss]

Thanks Duncan for your sucessful diagnosis of Tim's problem.

If we can get hold of a 2nd hand ECU then am more than happy to swap the capacitors over for him.

Well worth trying and if sucessful, it may become possible to attempt this kind of repair in the future.

Russ

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Successful? We don't know yet!

I've seen enough in my life to know that fault codes can tell you exactly what's wrong, or lead you on a wild goose chase.

Certainly the capacitors are a prime suspect. But there are other things in the system. The capacitors are charged up by an inverter circuit. It could be any part of that, though the most likely culprit IS the capacitors.

Looking at information on the Epcos website, they do 4 terminal capacitors of the ratings we found. So if we can confirm data, we might find the ones from RS are OK. But if the problem is the rest of the circuit, it won't help.

I only wish I could give a definitive answer, but I'm guessing on a lot of stuff, based on previous experience.

[BigRuss]

Well I suppose the proof of the pudding will be when the capacitors are replaced.

I would prefer to use new if we can get hold of them, but I suppose a good used ecu would do and give us instant access to the other components.

Russ

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I've found the manufacturer, but they don't list anything that will fit. I've emailed them but don't hold out much hope.

The capacitors have four terminals. The technical literature suggest this is to give the high pulse response so the standard ones might be worth a try, but might also still not work. The literature also doesn't say which terminal is which, so it would be a guess, or maybe a measurement once one is removed.

I really suspect the fastest route is going to be a donor ECU. Mind you, it seems the connection resistcnce is really critical, so a quick remelt of the soldered joints can't hurt.


OOh, look at this. A different manufacturer, but looks the same (only green). Bottom right picture:

http://www.vishay.com/capacitors/film/mkt1820-list/

[stocktake]

I have sent a pm to Willshott, some time ago I gave him the details of a breakers yard in East Yorkshire that had quite a few 75's in. Was very reasonable on cost too. Will see if that gets us anywhere? ( I've lost the address.........Doh)

[madmax1975]

Hi all i live in bury gtr manchester and close to some of the greatest breakers yards all in the same area pimhole bury and know that in these yards are a few 75s so im of work this week if i can have some ecu numbers and what you need i can pop down tomoz and have a look they are pretty good as i use them a lot hope this helps

[BigRuss]

Originally Posted by lowedb

I've found the manufacturer, but they don't list anything that will fit. I've emailed them but don't hold out much hope.

The capacitors have four terminals. The technical literature suggest this is to give the high pulse response so the standard ones might be worth a try, but might also still not work. The literature also doesn't say which terminal is which, so it would be a guess, or maybe a measurement once one is removed.

I really suspect the fastest route is going to be a donor ECU. Mind you, it seems the connection resistcnce is really critical, so a quick remelt of the soldered joints can't hurt.


OOh, look at this. A different manufacturer, but looks the same (only green). Bottom right picture:

http://www.vishay.com/capacitors/film/mkt1820-list/

It certainly won't hurt to try to remelt the solder and see what happens, can go down within the next couple of days and do that.

Russ