Brief Encounter II - The Sequel

jgra1 · Post by **jgra1** » 02 Jun 2009, 23:58

enjoy tomorrow Jim, and well done!

I spent tonight doing a 406 V6 rad, and oil and filter change, coincidentally, for someone

engine was pretty damn black inside!

MikeT · Post by **MikeT** » 03 Jun 2009, 17:37

Thanks Jim and xac - it was good to see your efforts rewarded with a smooth idle and nothing untoward. Bet you can't wait to unleash those horses and let it rip 8)

KP · Post by KP » 04 Jun 2009, 09:44

Good work Jim!

Dont forget to keep all that scrap metal and wiegh it in to get some cash back on it as im sure your sat on a small fortune in re-usuable metal

Cant wait to see you do the V6 manual project in the future now

Post by **CitroJim** » 05 Jun 2009, 08:29

Well, she's all back on her wheels after replacing the front discs and pads and she goes backwards and forwards quite well but.....

The autobox is stuck in emergency 3rd

Xac noticed that the engine lurched a bit when D was engaged and this is a symptom of the 'box in emergency 3rd. The engagement is a little vicious in this mode as the handbook warns.

I ran the Lexia across the gearbox ECU and all comes up fine. No faults logged (after remembering to hold the brake pedal down whilst faults are being recorded else a brake swich fault is logged) and everything looks good but when doing an axctuator test, the MV1 electrovalve does not appear to be operating. This is the one that determines if the 'box operates under ECU control, or in Emergency mode. The ECU however "thinks" it is operating this electrovalve.

There are several possibilities and it could even have been a pre-existing fault.

Recall that the normal/emergency slide valve (which is directly operated by MV1) in the old valve block was broken. Also, if the electrovalve is not operated but the ECU tries to maintain electronic control, at speed, both clutches B and E will be operated and recall that clutch B in the old 'box was burned out which will happen if B and E tries to engage at the same time with a brake also applied as the gearbox will effectively lock up solid until something gives.

It all makes a kind of sense. This could have been yet another reason for the original 'box failing. Maybe. There appears to have been so many potential causes of failure but hopefully the real culprit will soon reveal itself.

Now, there is another variable. The replacement valve block I used was off my spoares gearbox which was damaged in an accident. One place the 'box took a whallop was in the region of the area of the valve block cover where MV1 resides.

It looked OK but as it was untestable until all was back together, there was no way of telling.

I shall be looking for electrical faults first, especially as the signals from the gearbox ECU to the gearbox Kostal connector runs through the infamous 10AV loom and then looking that the correct signals from the ECU are present at the Kostal connector. It could even be a duff ECU..

I'm hoping I'll not need to dive into the valve block but if I do, it's not too bad as it is just possible, with care, to get the valve block out without lifting the whole engine and gearbox.

More news as it happens....

It's a setback but not a biggie... Still plenty of fodder to keep me interested in the project!

Post by **CitroJim** » 05 Jun 2009, 20:26

I did a brief spot of diagnostics this evening. The MV1 and MV2 electrovalves are not operating under ECU control.

I started by removing the Kostal connector on the gearbox (tricky in-situ

) and checking the DC resistance of the valve block electrovalves. All present and correct. I was helped here as the special toolkit I have on loan for the gearbox contains a breakout box for the Kostal connector although unfortunately not an in-line one.

I then borrowed the loom from the old valve block and wired it to the Kostal connector. Ignition on and engine running, I found no voltage reaching the electrovalve plugs.

The MV1 and MV2 electrovalves are supplied with a common 12V and they operate by the ECU earthing them. The common 12V supply appears to be missing.

Unfortunately time was against me this evening and that is as far as I got. Next step will be to check the wiring between the Kostal connector and the ECU and I'm praying I find a break in said wiring. If there is no break then it looks like something in the ECU has bid a fond farewell. Else that or it is missing one of its supplies, again due to bad wiring.

Tomorrow I'll get to see. If it is the ECU, it remains to be seen how repairable it is. The Lexia says it's fine so the problem will be in an output stage so may well be amenable to repair in the same way as a Hydractive ECU is.

If the problem was pre-existing, it would go a long way to explaining why Clutch B burned out and why the SIV slide valve spring was broken, especially if the problem began intermittently with the gearbox sporadically dropping into 3rd emergency at speed whilst the ECU was still trying to control the brakes.

Interesting. This may also go some way to explaining the occasional rough change and lurching that has been experienced by xantia_v6 that I believe once resulted in a broken engine mount donut. Co-incidentially, mine had a severely broken engine mount donut..

The plot thickens....

Sl4yer · Post by **Sl4yer** » 05 Jun 2009, 20:34

You'll get there Jim. It's been a fascinating read so far!

James

Xaccers · Post by **Xaccers** » 05 Jun 2009, 23:39

I think for xmas Jim, I'm going to buy you a deerstalker and curved pipe

Post by **xantia_v6** » 06 Jun 2009, 06:20

Jim, If you want to borrow an ECU (or anything else) for testing, I can spare one for a while.

Post by **CitroJim** » 07 Jun 2009, 19:24

xantia_v6 wrote:Jim, If you want to borrow an ECU (or anything else) for testing, I can spare one for a while.

Thanks for the offer Mike but I'm delighted to say there's no need

Between storms this afternoon I checked the continuity of the loom between the gearbox and ECU and no problems found.

Then, after an agonizing wait for the rain to ease off, I used the Lexia to re-initialise the ECU, then carried out an actuator test on the electrovalves and was delighted to hear a faint clicking from within the valve cover...

I then started up and lo and behold, an autbox that is no longer stuck in emergency 3rd

I then tested the gears and found all would engage smoothly with no big lurch and then I popped into Reverse and crept backwards.

I had a bit of a scare when I went to check for forward motion in D and found none. With the Lexia leads tangled around the gear selector I could not see the panel and found I was in N! Into D properly and she crept forward

So all it was in the end was a need to reinitialise the ECU because it had a new valve block attached

I reckon I'm the happiest person on this planet this evening

Koukku · Post by **Koukku** » 07 Jun 2009, 19:41

Congrats!

XantiaMan · Post by **XantiaMan** » 07 Jun 2009, 19:42

Great news Jim. Next step? Get that paintwork tidyed up!

Post by **myglaren** » 07 Jun 2009, 19:51

Excellent Jim. I'm so pleased that all that hard work paid off with no further trauma.

Going to try and shoehorn a Maserati engine in there next?

red_dwarfers · Post by **red_dwarfers** » 07 Jun 2009, 20:06

Nice one Jim!
That Lexia is quite a handy bit of kit

Im glad it was nothing that serious.

Deanxm · Post by **Deanxm** » 07 Jun 2009, 20:18

Thats good news indeed! so, been out for a thrash yet or have you been limited to crawling up and down the drive

D

Post by **CitroJim** » 07 Jun 2009, 20:33

Deanxm wrote:so, been out for a thrash yet or have you been limited to crawling up and down the drive

Just up and down the drive Dean, between the garage doors and my 1.9TD

Even that feels rather good!

Dare not take her out as she has no MOT, tax or insurance just yet. I'll be looking to get her MOT'd very soon, as soon as the drop links are replaced and the rear hydractive problem is sorted...

We're not quite done with this blog just yet