Anthracite XM 2.0 SEi Turbo Manual

[Aerodynamica]

PM gesendet

[Dieselman]

The door lock issue is the internal microswitch that detects the latch is fully closed moving away from the latch.

[Aerodynamica]

Well, had the Hydractive ECU out after fitting the replacement I purchased off of Matthew and decided to have a look at the condition of it. It looked pristine inside and no obvious sign of any bad bits. After I got the board out of the housing I noticed the printed circuit looked sort of 'crinkled'

Closer

Is this a sign of deterioration?

I reflowed two solder points that looked aged but that was all.

The replacement ECU behaves exactly like this one - automatic suspension works for the first kilometer then goes to hard mode. Looks increasingly like the speed sensor and/ or the pedal sensor is to blame after all (?)

(I've been testing the speed sensor and the speed 'interface' used for the trip computer seperately but I'll go in to that at a later date! needless to say the speed sensor is looking like it isn't actually working)

[Aerodynamica]

I've been working on the hydractive for months now but today there was a breakthrough. After testing the speed sensor off the car and discovering there was a signal from it and testing the continuity between the sensor's connector to where it connects to the speed interface unit and finding it all buzzed out ok I turned to the connection to the Hydractive ECU from the speedo interface as this was what I believe the signal (boosted by the speed interface unit) traveled to the ECU by.

Basic recap: it would always start up and run with soft suspension that would switch soft-hard etc as you drove and it was great but then, less than a mile later it just goes to hard and stays htat way. It was the action of the accelerator pedal sensor that set it off like this but the only fault code ever recorded on the ECU was #24, vehicle speed sensor.

After lots of research and a lot of help via PM from Chris and John, I found the Hydractive ECU does EVERYTHING as a function of speed input. No speed info then it just goes 'off'. It likely doesn't like the contunual accelerator pedal inputs without any other input such as speed and so it faults out. If you disconnect the accelerator pedal it stays in soft mode permanently as without the speed info, again it thinks the car is stationary.

Everything was pointing to the speed sensor.

So, tested the circuit, OK, tested the sensor, OK, fitted other speed sensors - same result. Heard tale of the 'speedometer interface' failing. Turned out this is only fitted to XMs with the trip computer (and Peugeots etc) and according to the wiring diagrams when it's not present, the speed sensor connects directly to the Hydractive ECU (at pins 13 and 6 of the black multiplug of the ECU) but where the speedo interface is present, pin 6 isn't used and the speed sensor connects to the 9 pin plug of the interface (pins 7 and 8) and then one of the outputs of the interface goes to pin 13 of the ECU. I reckoned the interface or its wiring was duff and the speed information was being lost.

Also, the trip computer didn't work so also pointed towards the speed interface being duff.

I found there was no continuity between the pin of the speed interface (pin1) and pin 13 of the black connector of the ECU so that was a start but I wanted to bypass the speedo interface completely by wiring the speed sensor directly to pin13 and 6 and that's what I have just done and it has now driven 9 miles with functioning hydractive! The inputs from the accelerator pedal are working the electrovalve accelerating and decelerating but it restores to soft a second later and continues for miles so it is looking good.

It was a joy to drive.

So the next step is to replace the black 15 pin ECU plug and rewre the connections to the speed interface and hopefully it'll continue to work and also restore the trip computer...

So I'm looking for a replacement black connector for Hydractive 1 suspension (H2, H3) if anyone has one with a good few inches of wiring on it up for grabs?

[xantia_v6]

The crinkled appearance of your PCB above is not a defect, it is an artefact of the manufacturing process. PCBs have a layer of solder-resist (the green coating) to prevent the PCB from picking up too much solder in the wave-soldering process that would have been used. Often the solder resist is applied to the bare copper tracks before tinning, but in this case the copper tracks have been entirely tinned before the solder-resist was applied
When the PCB has later gone through the wave-soldering machine, the solder under the solder-resist has melted, and the wave pressure produces that wrinkled effect on larger areas of copper. This is a bit unsightly, but causes no problem in service.

[Aerodynamica]

Thanks, and I can confirm it works fine too!

[Aerodynamica]

Still working!

[Dieselman]

After all that, just checking inputs at the ECU would have revealed the problem, which was being accurately recorded.

That's not a criticism, just an observation that the correct testing procedure normally reveals the problem


A good fix though.

I was reading about the ongoing stalling issue and wondered if either the throttle plate was sticking or the small vacuum pipe connected to the throttle body was blocked with carbon.
Try adjusting the throttle plate to have it slightly more open at idle. I recall on Bosh Motronic fitted to VW Golf GTI, you have to put the ECU into limp home mode, which parks the throttle actuator, by disconnecting the coolant sensor, revving the engine over 2500 Rpm, then set the idle to 900Rpm.
The throttle actuator then reduces the idle speed when in operation.

If the baseline setting is below 900Rpm, the engine stalls on coasting to a halt.

[Aerodynamica]

Yea but how would you check the inputs at the ecu when the ecu doesn't operate with the plug off? All imput connections were checked i.e the continuity of every sensor, their specified resistances where applicable and the power and earth at the pins. All checked out. It was a case of finding why the speed sensor was testing ok on the car, at its connection to the interface thing but coming up as a fault on the ECU.

Actually the fault code was incorrect because it recorded 'speed sensor' as the fault but the fault was with the speed interface wiring.

Also, in my further defence; I have had absolutely NO garage facilities for the past 6 weeks to continue for another week or so.. Tesco car park if surprisingly useful for car fixing..

I'm interested in the stuff about the throttle etc though. Never did check the rubber vac pipe was clear - just checked the fitting at each end. I also found out there is a second pipe from the connection of the vac pipe on the ECU that goes to the actual vacuum sensor on the pcb and I suppose that could be perished too. I want a spare ECU though before I investigate it further but so far no joy finding one.

All I can say about the stalling at junctions (though the throttle response problem is a bigger concern) is that it seems to be related to the HP pump being under sustained load where the steering is slightly right or left hand down. I think it's causing a little extra load that's just enough to stall it. But it barely does it at all now.

[Aerodynamica]

Arg, I've just fixed the HP pump suction pipe (it was sucking in air at the LHM tank pick up) so that's one thing off the list of fixes on the car...... until the parking brake just.... er.. broke....

cable has snapped (or something) - must be the single upper cable because the pedal itself has gone all 'floppy' - ugh.. what next..

I'm thinking this cable is the total 'mare to change out. Anyone have a spare available?