I've got a 2009 Mk II Superb, 4x4 2.0 diesel (170 PS) and last August (in Italy) it died. I finally got the car repatriated back to UK this week. I'm too ill to do my own repairs but my mechanic is pretty good but we are baffled...

1. No fault codes present

2. Battery (Bosch - less than 1 year old) is dead as a doornail and not holding charge (could be because it has been stood for months?)

3. Mechanic found no signal from crankshaft sensor (engine speed)

4. This has been stripped out and put back together (mechanic was certain this was the problem)

5. Still not starting and still no signal (engine turns over OK)

 

Has anyone come across this before or have any idea how to proceed?

 

Waiting for answers in hope!

Rob T aka Trenchman

Was the wiring to the crank sensor checked through?

Hi,

I don't know. But now that you've flagged it up I'll let my mechanic know. We're just looking for possible avenues at the moment.

 

Thanks very much for the tip, it's very much appreciated.

Tryed changeing the battery?

something rings a bell about a new bosch sensor that had been manufactured with reversed polarity. symptoms pointed to a faulty sensor, replacement did not fix until after weeks of investigation the wires were cut and reversed, they had discovered using an oscilloscope the wave form produced was backward.

trouble is i can not be sure it was the crankshaft sensor now but it rings a bell.

^ I think it was a crank sensor. A Diagnose Dan YouTube video, I think. 

 

I'll look up the wiring info this evening if I get a chance.

Thanks to all those replying - It's massively appreciated! My mechanic being continuously updated. I haven't driven my baby for three months and I miss her!

Pin 1 at crank sensor connector - yellow/blue wire - comes from engine ECU pin 25 (+5V)

Pin 2 at crank sensor connector - yellow/purple wire - comes from engine ECU pin 52 (Signal output)

Pin 3 at crank sensor connector - brown/red wire - comes from engine ECU pin 53 (0V)

 

With ignition on, I think you should be able to measure 5V between pins 1 and 3 of the sensor connector. If you do see that, it proves 2 of the wires are intact.

Thanks for this!

Did you resolve the issue, Trenchman?

 

 

Sorry for delay but have been in hospital with sepsis (I have cancer and I'm very prone to these sort of things) 

Hallelujah, yes! 

The lack of output signal was a red herring (due to faulty test equipment) and the problem turned out to be a knackered high-pressure fuel pump. It seems that a faulty fuel sensor caused the pump to overload and fail. Once (expensively) replaced all fell into place and she's running like an absolute sweetheart now. 

 

4 hours ago, Trenchman said:

have been in hospital with sepsis

My sympathies; been there, done that due to an infected dialysis line.

Mine also, I'm glad that you pulled through. I was touch and go with it about 4 years ago, I would not wish it on anybody.

 

I rarely see the Médecin and don't over-react to things but this was one occasion when I knew that something was very very wrong, they said to come back in the afternoon for a consultation which was very good but I politely and firmly said that I would remain there until somebody, anybody, could see me, I doubt that I could have driven home.

 

I was seen by a locum (it was the holiday period) and she knew straight away although did not say so, she inspected every inch of my body for cuts (I now know why) before calling for an ambulance and arranging my admission to the hospital.

 

They never did find what the entry route was (if that is what you call it in English).

Edited 24 November, 20223 yr by J.R.

On 24/11/2022 at 20:26, KenONeill said:

My sympathies; been there, done that due to an infected dialysis line.

Thanks for the support. It's the fifth time this year!

On 24/11/2022 at 21:16, J.R. said:

Mine also, I'm glad that you pulled through. I was touch and go with it about 4 years ago, I would not wish it on anybody.

 

I rarely see the Médecin and don't over-react to things but this was one occasion when I knew that something was very very wrong, they said to come back in the afternoon for a consultation which was very good but I politely and firmly said that I would remain there until somebody, anybody, could see me, I doubt that I could have driven home.

 

I was seen by a locum (it was the holiday period) and she knew straight away although did not say so, she inspected every inch of my body for cuts (I now know why) before calling for an ambulance and arranging my admission to the hospital.

 

They never did find what the entry route was (if that is what you call it in English).

Thanks bud. This is my fifth sepsis hospitalisation this year but I keep pulling through!

Mon dieu!

Glad to hear you managed to resolve the issue and sorry to hear about your health problems.