New owner a lot of problems Updated

Sl4yer · Unread post by **Sl4yer** » 18 Feb 2010, 19:45

lefgrter wrote:I have just thought of something.... when the car is stationary (speed 000), engine running, the suspension is in soft mode. If i press the accelerator pedal suddenly all the way down and release it before the engine blows out, what the suspension should do stay in soft or momentarily change to hard mode?

I believe it will stay soft unless the ECU sees a vehicle speed greater than 30kph.

James

Unread post by **CitroJim** » 18 Feb 2010, 20:21

That's my understanding as well James. I believe you can occasionally provoke a switch to hard on blipping the throttle but only if the car has been driven very recently.

The most most important inputs to the ECU are speed, throttle position and steering wheel angle.

lefgrter · Unread post by **lefgrter** » 18 Feb 2010, 20:43

CitroJim wrote:That's my understanding as well James. I believe you can occasionally provoke a switch to hard on blipping the throttle but only if the car has been driven very recently.

The most most important inputs to the ECU are speed, throttle position and steering wheel angle.

According to citroen repair manuals and under the title "Electrical specifications : Hydractive suspension", paragraph "6.1 Accelerator depressed thresholds",
Whenever the sensor data exceeds the threshold value, the suspension system switches into "firm" mode.
Time delay 1 to 1,5 seconds.

Accelerator pedal depressed (spacing/ 25 ms)

Vehicle speed (miles/h)___NORMAL___SPORT
0-9______________________2________1,3

That is why i am asking if i can provoke for a second firm mode.
Since the lexia is available it is easy to see the mode change.

Unfortunately its impossible to provoke an intermittent speed sensor fault
at least to have the emergency strategy so the ECU switch to firm assuming that the car moves with 60 miles/h.
Lefteris

Sl4yer · Unread post by **Sl4yer** » 18 Feb 2010, 20:56

I'll give it a try tomorrow.

James

lefgrter · Unread post by **lefgrter** » 18 Feb 2010, 21:10

Sl4yer wrote:I'll give it a try tomorrow.

James

I will wait

Sl4yer · Unread post by **Sl4yer** » 19 Feb 2010, 16:44

Just tried mine, and couldn't get it to switch to Firm mode with the throttle, as I expected. All your other readings look the same as mine with the engine off, including the AUTO sign.

When do you get your new speed sensor?

James

lefgrter · Unread post by **lefgrter** » 19 Feb 2010, 19:40

Sl4yer wrote:Just tried mine, and couldn't get it to switch to Firm mode with the throttle, as I expected. All your other readings look the same as mine with the engine off, including the AUTO sign.

When do you get your new speed sensor?

James

Thanks.... This was a relief to me

As my ECU seems OK.
Since i didnt get the sensor today maybe Monday or Tuesday.
Sunday, after changing the strut and LHM with hydraflush, i will try the wire from speedometer to ecu thing.

Unread post by **CitroJim** » 19 Feb 2010, 20:19

Lefteris,

Do you have access to an oscilloscope to measure the speed signal at the ECU?

If you do then I should be able to measure one of mine and get an idea of the amplitude/frequency you should see at the ECU for a given road speed.

lefgrter · Unread post by **lefgrter** » 19 Feb 2010, 20:56

CitroJim wrote:Lefteris,

Do you have access to an oscilloscope to measure the speed signal at the ECU?

If you do then I should be able to measure one of mine and get an idea of the amplitude/frequency you should see at the ECU for a given road speed.

Unfortunately I don't have access to an oscilloscope. I will so the test with wires and change the sensor next week. I want to think that i will fix the problem. If none of the above solve the problem I will try to find an oscilloscope and see what happens.

Thanks again
Lefteris

lefgrter · Unread post by **lefgrter** » 28 Feb 2010, 20:47

Eventually i must have a haunted car....
The new speed sensor is installed,the wiring rechecked, but the problem still remains. The only thing left must be both ECU's. i will try to find a spare one to check and see. Any other ideas??

As for the other problem i found that the air gets in from the returns

I decided to fit a transparent tube to the pump, and feed the circuit sinking the tube directly in the LHM (I mean Hydraflush). When the car was low and the 12mm bleed screw open (the circuit depressurized) the LHM war clean and without air. When i closed the screw and the car started to rise and the LHM level in the tank started to getting low, the air started to show in the feed hose, as the main return pipe (next to feed pipe returns foamy LHM.
After that i sealed the plastic lid with red silicone and fitted the clear hose to its normal position on the tank, the result was when the engine revs high some big bubbles and millions of tiny ones appears.

Here is the returns from the brake valve

and here is the foamy returns from the main return pipe

When i start steering the steering wheel some huge bubbles appears in that pipe.
So i assume that as the LHM gets in the tank with lot of air that air gets in the feed pipe ant the problem wets worse and worse.
I believe that if somehow i manage to find the air leak and stop it my problem will be solved. I think that the steering ram is the prime suspect here, but i don't know how to check it .
All those photos were taken with the car low and depressurized (I think that with the bleed screw open the only thing that works is the steering ram as the rest of the circuit is disconnected and the LHM returns directly from the pump to Tank through pressure regulator.)

Unread post by **CitroJim** » 28 Feb 2010, 21:00

Hi Lefteris,

That is odd with the speed sensor

Time to get an oscilloscope on the go I reckon. Two faulty ECUs seem very unlikely.

Air in the LHM. Yes, you are right that how you have tested, the air is coming via the steering system.

One potential place is cracks in the return pipe from the steering pinion return valve. In an RHD car, this pipe begins as a metal pipe and a rubber pipe joins it. In fact the opposite end of the pipe you have disconnected showing the air. Often this pipe cracks where it is joined to the metal pipe. I would assume a similar arrangement on an LHD car. That rubber pipe is serious fun to replace. I had to replace it on my V6 and access is rather difficult

It is nearly hidden but will give the game away by being wet and making the subframe wet.

The steering ram leaks when it fails and is usually obvious.

Less obvious is leaks in the steering pinion valve. This is the assembly attached to the steering rack just below where the steering column joins. It has two seals and can either leak externally by the steering wheel universal joint or internally into the rack itself. This leak can go unnoticed for a while until the rack becomes full of LHM and it leaks through the steering rack gaiters.

lefgrter · Unread post by **lefgrter** » 28 Feb 2010, 21:31

CitroJim wrote:Hi Lefteris,

That is odd with the speed sensor Time to get an oscilloscope on the go I reckon. Two faulty ECUs seem very unlikely.

Thanks for the fast answer

I agree that 2 faulty ECU's is unlikely. But also 2 sensors with the same problem?
As i told, someone has opened the engine ecu for tuning purposes. I will open it and see if it is altered in any way first. How can i test the speed sensor with an oscilloscope?

Next week i will change the whole rack and valve and hope to solve the problem. The good think is that i have made myself an expert

I can bleed the brakes in 3-4 minutes with all wheels on the car. With rubber gloves my hands dont even get dirty.

A small 8mm spanner is my best friend for the past 2 months

Unread post by **CitroJim** » 28 Feb 2010, 21:35

I will have to put an oscilloscope on one of mine Lefteris but the problem is that one of my Activas is immobile (all in bits!) and my other is away from home at the moment.

I can try it on my V6 perhaps as the speed sensors are the same. It will be a few days before i will be able to do it.

Can you bleed the front brakes without removing wheels as well?

lefgrter · Unread post by **lefgrter** » 28 Feb 2010, 21:41

Yeap, It is very easy if you know exactly where to look for the bleed screw.
I have a difficulty to fully bleed the front ones only if i want to fit the small tube to collect the LHM, as for that purpose i need to use both hands behind the wheel.

lefgrter · Unread post by **lefgrter** » 11 Mar 2010, 18:16

It is working again.
For the first time i felt what it is like driving an ACTIVA.
It is exactly like driving a Mercedes with ABC suspension, only $$$$$ cheaper.
The problem with the air in the circuit was a tiny crack on the triangle plastic part of the HP pump. A new pump installed now. The STOP light goes off in the morning in about 20 seconds!!!
The Speed sensor was ok But Both ECU's failed to get the signal. After all i got another suspension ECU, and left my chiped engine ECU as it doesn't seem to have any other problem.
Now the car work's almost perfectly. I am waiting to receive a new set of activa roll corectors from France, as mine are very worn. I expect to have them next week.
I am going for a ride now.....
By the way this weekend i am going to fix some other minor things (airbag open circuit problem, abs sensor and intall a new istrument panel as mine has some cracks).
Can any one mesure the distance shown in the following photos for me so i can adjust the front and rear height more easily?

For the front

For the rear

I think that the front is a bit high

Regards
Lefteris