Selespeed issues...major

[SeleMatt]

Okay.

About 12000 k's (18mths approx) ago I had a new clutch kit installed. Complete.

October last year I was unable to select any gears and the 2 sensors next to the gearbox ecu were replaced. Everything is fine again until now.
Just been away for 3 days. Coming to a red light, the clutch failed to engage and the car stalled....fortunately there was no one in front of us...
Clutch also became snatchy,(especially when wet) doing u turns on or close to full lock from a standing start.
The next day while going down hill and then making a right turn, the car slipped into neutral. Rolled over to the side of the road. Unable to select any gears like last October. After trying several different ways to get going again, had a win. On the way home yesterday the car did both of these of these things multiple times (either the clutch failing to engage coming to a stop or the car slipping into neutral on down shifts (never up) but somehow managed to get home although frustratingly, not into the garage. Now parked in the street. Tried every trick now and it's stuck in neutral.
The codes when I got the laptop hooked up were;

PO856 invalid signal - Traction control issue
PO805 signal high - Clutch position sensor. Certain it comes with the new master cylinder so should be fine. Will check.
P2908 signal high - Clutch sub-system...no idea
P290B signal low - Can only find reference to Alfasud with this code....

Selespeed and clutch fluid are fine
Hydraulic pressure 36 to 46 which is also fine.
No visual leaks anywhere

Cleared the codes and tried again. P2908 instantly reappears. I've disconnected the battery in the hope that tomorrow I can get it in to the garage...



Any assistance/advice most welcome.

[bazzbazz]

PO805 signal high - Clutch position sensor. Certain it comes with the new master cylinder so should be fine. Will check.

Did you specifically have this changed, as changing the Master Cylinder is not part of a normal clutch change, but the SLAVE cylinder is.

PO805 signal high - Clutch position sensor.
P2908 signal high - Clutch sub-system...no idea
P290B signal low - Can only find reference to Alfasud with this code....

Cleared the codes and tried again. P2908 instantly reappears. I've disconnected the battery in the hope that tomorrow I can get it in to the garage...

P2908-Clutch System is an indication that there an issue with the Master Cylinder, internal seals may have failed?
Or if the master cylinder is not new could be the Clutch position Sensor. (P0805)

[SeleMatt]

Thanks Baz.

The eye-watering invoice says 'clutch master cylinder - complete' Would that include the sensor? I have no 'clutch position sensor' itemised on its own. It was changed on the advice of the mechanic who did the work.
The slave cylinder was of course, replaced.

Here's a link below. I'll assume this is what I paid for and it shows the sensor. For illustration purposes only. Bought it from our good friends in Melb.

https://alfaworkshop.co.uk/parts/159_Selespeed_pump.shtml

[SeleMatt]

Beyond that:

With MAR on and engine off you can select all the gears up and down. As soon as you start the engine in the normal manner I get P2908 instantly and stuck in neutral.

below are the MES parameters

Gear/engage position
32.568 mm
Selection position
81.918 mm
Clutch pressure plate travel
3.912 mm
Clutch pressure plate reference
17.664 mm
Accelerator pedal position
0.0 %
Hydraulic circuit pressure
47 bar
Engine temperature
81 °C
Battery voltage
13.4 V
Engine speed
801 rpm
Clutch disc RPM
801 rpm
Clutch engaged position (self-adjusted)
16.488 mm
PIS spacer closed position (self-adjusted)
3.408 mm
Solenoid valve current at zero flow
1107.6 mA
Gear selection threshold (N/R)
83.916 mm
Gear selection threshold (1st/2nd)
107.004 mm
Gear selection threshold (3rd/4th)
128.316 mm
Gear selection threshold (5th/6th)
150.516 mm
Secure engagement threshold (N)
34.338 mm
Secure engagement threshold (1st)
20.178 mm
Secure engagement threshold (2nd)
40.533 mm
Secure engagement threshold (3rd)
19.529 mm
Secure engagement threshold (4th)
41.182 mm
Secure engagement threshold (5th)
20.060 mm
Secure engagement threshold (6th)
40.828 mm
Secure engagement threshold (R)
19.883 mm
Odd gears selection sol. valve current
0.0 mA
Even gears selection sol. valve current
0.0 mA
Clutch solenoid valve current
0.0 mA
Actual engine torque
-7 Nm
Requested engine torque
-500 Nm
Vehicle speed
0 km/h
Gear selector lever position
Neutral req. from lever
Gear engaged
N
Gear requested
N
ECO/SPORT button
Released
door
Closed
Brake pedal
Released
Ignition key position
ON
Pump relay control
OFF
Start-up enable relay
OFF
Acoustic signal (buzzer)
OFF
Selection solenoid valve
Not active
Starter circuit
Not requested
Longitudinal acceleration
m/sec²
Gearbox oil temperature
43 °C
Clutch temperature
59 °C
Clutch degradation index
8189
System ON time
238638 min
Clutch overtemperature time
0 sec
Missed selection/shift counter
0
Clutch disc RPM too high counter
0
Missed gearshift counter
0
Clutch insufficient release counter
52
Clutch engaging problem counter
0
Total gear changes counter
770745
Gearbox/clutch self-calibration
Not performed

Clutch insufficient release counter at 52 times is interesting....

[bazzbazz]

Well first thing I would do is speak to the whoever did the clutch replacement and get it taken back to them, as everything will still be under warranty, so until then do nothing, touch nothing or you'll void the warranty.

The eye-watering invoice says 'clutch master cylinder - complete' Would that include the sensor? I have no 'clutch position sensor' itemised on its own. It was changed on the advice of the mechanic who did the work.

Clutch Position Sensor is part of the Clutch Master Cylinder assembly, its the sensor fitted in the photo.

The only things left in the hydraulic system are the Pump and Accumulator, and the fact that you can change gears ok without the engine running indicates that these are working ok.

This is all supposition of course, not being there to do a hands on assessment and all. 

[bazzbazz]

Well first thing I would do is speak to the whoever did the clutch replacement and get it taken back to them, as everything will still be under warranty, so until then do nothing, touch nothing or you'll void the warranty.

Sorry, my bad, got confused between when the clutch and associated parts were replaced and to when everything started playing up again.

At a minimum all parts and labour should be covered for 12 months/20,000 km, but some workshops, depending on what work was done will cover there work for longer periods. As I said, give the workshop a call and explain the situation to them and see how they respond.

As I said before, without being able to a hands on diagnosis there little further advice I can give. I am sure the workshop who did the work will do the best they can for you in the circumstances.

[SeleMatt]

Just to confirm Baz, are the 2 sensors tucked away to the left of the ecu both called engagement sensors...or not?

[bazzbazz]

One is the "Engagement Position Sensor"(Upper Sensor), the other is the "Selection Position Sensor"(Lower Sensor), but they are both the the same part & part number (6000100088)

They are NOT compatible with the "Clutch Position Sensor" mounted on the Master Cylinder, as it is a simple potentiometer, where the other two are Hall Effect Sensors.

[SeleMatt]

Thanks Baz. I was aware of that distinction. So if the engagement sensor was incorrectly pre-loaded, could that cause it to wear out faster or would it have not worked at all after installation?

[bazzbazz]

It wouldn't have worked at all and would have throw up error codes.