Central Locking System-How to check connections?

[emperorphobos]

Hi, 

 

I've used the Durametric Diagnostic on my 1999 C4 and have a list of fault codes and instructions on what to look for, but where do I find the plugs and pins? Are they located within the M535 module or somewhere else? Any help would be very much appreciated.

 

List of faults:

 

46
No central locking possible
Central locking synchronization
Status: Present
Number of times DTC present: 1
  58
No current in tank servo motor despite relay actuation
Check connection on pins 5 or 10 and 1 or 2 on shift elements
Status: Present
Number of times DTC present: 1
  49
No communication with PST 2
This fault is stored if the K-lead is short to ground
Status: Not present
Number of times DTC present: 1
  60
Central locking limit position locked not reached
Switch for central locking is faulty
Status: Present
Number of times DTC present: 5
  33
No passenger compartment monitoring
Interior monitoring sensor faulty
Status: Present
Number of times DTC present: 1
  61
Central locking limit position unlocked not reached
Check pin 3, 5, 28
Status: Not present
Number of times DTC present: 1
  47
No central locking possible
Central locking synchronization
Status: Not present
Number of times DTC present: 1

 

[JFP in PA]

 

Hi, 

 

I've used the Durametric Diagnostic on my 1999 C4 and have a list of fault codes and instructions on what to look for, but where do I find the plugs and pins? Are they located within the M535 module or somewhere else? Any help would be very much appreciated.

 

List of faults:

 

46

No central locking possible

Central locking synchronization

Status: Present

Number of times DTC present: 1

  58

No current in tank servo motor despite relay actuation

Check connection on pins 5 or 10 and 1 or 2 on shift elements

Status: Present

Number of times DTC present: 1

  49

No communication with PST 2

This fault is stored if the K-lead is short to ground

Status: Not present

Number of times DTC present: 1

  60

Central locking limit position locked not reached

Switch for central locking is faulty

Status: Present

Number of times DTC present: 5

  33

No passenger compartment monitoring

Interior monitoring sensor faulty

Status: Present

Number of times DTC present: 1

  61

Central locking limit position unlocked not reached

Check pin 3, 5, 28

Status: Not present

Number of times DTC present: 1

  47

No central locking possible

Central locking synchronization

Status: Not present

Number of times DTC present: 1

 

 

It is referring to the central locking/alarm module, which is under the driver's seat.

 

One thing that caught my eye was fault 49, "no communications with PST 2", which says one of your main communications links (K-line) is shorted to ground.  I would track that down first, as it could be the source of everything else.

[emperorphobos]

Thanks for the reply. My issue is that I don't know or understand if the module that we are talking about is the M535 I can locate under the seat.

 

This is a 'closed' module, I can't open it as far as I can see and there are 2 different group of cables that going inside, one in a light blue socket and the other one in the black one. Is this the correct module that everybody talks about?

 

If yes, where can I start looking for the issue with ground? Any help is strongly appreciated.

 

Thanks!

[emperorphobos]

And to add on this one, about Durametric: As far as I read came to my attention that alarm codes are not clearing out. That means that i.e. the (49) that you mentioned is it an actual problem or not since the Status is: not present? 

[JFP in PA]

Thanks for the reply. My issue is that I don't know or understand if the module that we are talking about is the M535 I can locate under the seat.

 

This is a 'closed' module, I can't open it as far as I can see and there are 2 different group of cables that going inside, one in a light blue socket and the other one in the black one. Is this the correct module that everybody talks about?

 

If yes, where can I start looking for the issue with ground? Any help is strongly appreciated.

 

Thanks!

 

 

Yes, it should look like this:

 

 

 

You are going to need a wiring diagram to start tracing the K line circuit.

 

[emperorphobos]

Thanks! K-line is the blue one I guess?

[JFP in PA]

Thanks! K-line is the blue one I guess?

 

You can see the K lead on the lower right of the diagram, circuit is DR/BK colors.

 

I believe that it is also pin 88 at the DME.

[emperorphobos]

I'm coming back since I found what's going on and to publish a more explanatory diagram. 

 

So, the cable seems to be rusted and I'll try to solve it. The diagram I'm posting is the wiring. The cables we were talking about are coming out from the blue socket.

(PS: This is a ultra high resolution file in order to be able to view everything correct)

[emperorphobos]

Back again, with another question if someone knows of course.

 

So, my issue is with pins 5 and 10 that gets the signal for close or open fuel tank. I tried to call different repair shops in my area and none of them can take care this issue, except of course Porsche dealer that needs the car there for 2 days and they'll charge me $165/h (with an estimation of 5+ hours). I have already replaced the fuel tank actuator (If i call it correct) but didn't solve the 58 error. It's obvious that is the cable between there and the module that is lost in space behind the firewall and I'm unable to checkit.

 

I'd like to know is it possible if I connect (like short) pin 5 to pin 10 or make some other combination i.e. pin 10 + ground to override the sensor in order for the module to see that the fuel cap is closed and be able to have my car lock again?

Edited April 20, 2016 by emperorphobos

[JFP in PA]

Back again, with another question if someone knows of course.

 

So, my issue is with pins 5 and 10 that gets the signal for close or open fuel tank. I tried to call different repair shops in my area and none of them can take care this issue, except of course Porsche dealer that needs the car there for 2 days and they'll charge me $165/h (with an estimation of 5+ hours). I have already replaced the fuel tank actuator (If i call it correct) but didn't solve the 58 error. It's obvious that is the cable between there and the module that is lost in space behind the firewall and I'm unable to checkit.

 

I'd like to know is it possible if I connect (like short) pin 5 to pin 10 or make some other combination i.e. pin 10 + ground to override the sensor in order for the module to see that the fuel cap is closed and be able to have my car lock again?

 

Not that I am aware of.