[1.2 ANY] won’t start in either P or N

[Erling]

Hello,

 

Please forgive my lack of German.  I’m one of a few hardy souls running a 1.2 tdi here in the UK.  Sadly it has developed a most frustrating fault which VCDS is failing to diagnose.  Basically, on occasion it won’t start.  Moreover, it won’t even try to start.  We have performed the basic reset and because the voltage was out or tolerance, have replaced the master slave cylinder (which now has the hall sensor mod) however on occasion, the problem re surfaces.  It won’t start in either P or N I should add. 
 

thanks 

 

Erling 

[Lupo_3L]

Are there no fault codes in the ECU?

How's the clutch voltage?

[Erling]

I’m going to rescan it this evening but previously there were not.  The voltages post change sat with the 1.85-1.95v range.

 

This was after I completed the last basic reset I did before the Clutch Slave cylinder was replaced 

[Lupo_3L]

Do you know the age of the pressure actuator of your hydraulic pump?

Or say it that way: How long does it take form opening the door and starting the pump, until it switches off?

These error messages, at least two of them, are a common result of a very old pressure actuator since pressure drops too fast when pulling the clutch.

The mileage of the car would be also interesting since some faults come with a worn out transmission.

Bearbeitet 28. November 2023 von Lupo_3L

[Erling]

20 minutes ago, Lupo_3L said:

Do you know the age of the pressure actuator of your hydraulic pump?

Or say it that way: How long does it take form opening the door and starting the pump, until it switches off?

These error messages, at least two of them, are a common result of a very old pressure actuator since pressure drops too fast when pulling the clutch.

The mileage of the car would be also interesting since some faults come with a worn out transmission.

The car has done 206,000 miles (so barely run in!!).  The actuator is almost certainly not original to the car as the previous owner ran multiple 3L’s most lupo and an a2 and it appears swapped bits about.  When I acquired the car in 2021 the actuator failed and the previous owner provided a known working one.  
 

I will check how long the pump stays on for prior to scanning again later when I am back with the car. 

[Erling]

Sorry, I think I have misunderstood.   Do you mean the accumulator?  If so, this was replaced with a BMW unit and the associated @Mankmil adapter late last year 

[Lupo_3L]

Yes, I meant the pressure accumulator.

Don't know about the Febi Quality in this regard but one friend in Vienna had it and it lasted only one rear until it caused problems.

[Erling]

The pump ran for 20 seconds on opening the door.   I’ve not scanned the car as it started!!!! From neutral initially after holding the ignition against the spring for circa 3 seconds.  This was after moving the selector down from P via R & N to D then back up to P (it wouldn’t start in P) then down to N.   It now starts from P & N.  

[Mankmil]

vor 5 Stunden schrieb Erling:

We have performed the basic reset and because the voltage was out or tolerance, have replaced the master slave cylinder (which now has the hall sensor mod) however on occasion, the problem re surfaces.  It won’t start in either P or N I should add. 

Have you ever replaced the clutch and the guide sleeve? There is a typical mileage of around 250,000 km when the guide sleeve is worn out. 

 

 

This affects, that the clutch's target position can't be  reached within the tolerated delay. After the first occurrence the control unit avoids the engine start in "STOP" position until you do a basic setting. Often after a few kilometers it avoids the engine start in STOP again.

The "open circuit" failure code usually occurs after unplugging the hydraulic pump. Would you delete the errors once again and do a test drive, please? If the open circuit failure is set again there could be a bad contact in the harness or one of the plugs. 

 

vor 3 Stunden schrieb Erling:

Do you mean the accumulator?  If so, this was replaced with a BMW unit and the associated @Mankmil adapter late last year 

Many people replace the accumulator aiming to repair less pressure in the hydraulic system. Often a new accumulator helps but it doesn't solve the main problem: worn out gaskets. These "rubber" gaskets lay in oil for more than 20 years.

 

vor 34 Minuten schrieb Erling:

The pump ran for 20 seconds on opening the door.

Anytime when the car was parked for a longer time? This is definitely too long. A healthy system starts immediately using the time from opening the door until turn of the key.

[DerWeißeA2]

Moderator:

Question moved to its own topic.

[Erling]

Thanks for coming back @Mankmil I’ll respond fully later 

[Erling]

Having been back through the service history, I can confirm the following;
• New Clutch 18.04.10 @ 109918 miles.
• New Gearbox 02.02.15 @ 149406 miles.
• Clutch Actuator, new Hall Sensor fitted. 04.09.17 @ 166318 miles.

I believe the Clutch and Gearbox replacements were carried out by 
an Audi main dealer. I’d therefore expect the clutch guide tube to have been replaced IAW the VAG tech bulletin but will try and confirm with the last owner. 

[A2 HL jense]

You can inspect it with a endoscope Camera as shown here

 

 

Your workshop should have one.

 

https://www.aliexpress.com/item/1005005599312123.html?spm=a2g0o.productlist.main.31.15cc781cpbZmKL&algo_pvid=2ba14af0-625a-4cd9-b57a-5f5e81289a79&algo_exp_id=2ba14af0-625a-4cd9-b57a-5f5e81289a79-15&pdp_npi=4%40dis!USD!40.78!26.91!!!40.78!!%40211b612517013303064386875ed7fc!12000033702882960!sea!DE!175933094!&curPageLogUid=1wAOvjrvLEIc

 

 

Bearbeitet 30. November 2023 von A2 HL jense

[Erling]

Thanks @Mankmil I’ll talk to them about it.  Will run another scan tomorrow.