CAN bus problems I think

[mickday]

Hi,
I occasionally get weird electrical gremlins, which show symptoms such as instrument display showing 'display faulty visit workshop' and also has been known to show other errors such as not acknowledging it was in park so would not allow me to start the engine would not even allow me to move gear sector out of park.

Temporary solution to get working was to remove battery temporarily which then reset everything back to normal.

I have put it on Star and the stored events which appear to me to be relevant are: System Diagnosis -> Event memory

9341: CAN communication of control unit Pass-side Sam is in single-wire mode (CAN bus High)
9372: CAN communication of control unit Dr-Side SAM is in single-wire mode (CAN bus Low)

When looking further at these errors:

9341: Cable from component X30/7 (Left CAN voltage distributor connector) (conn 3, pin 2) to component X30/6 (CAN voltage distributor, cockpit) (conn 1, pin 2)
Cable from component X30/6 (CAN voltage distributor connector, cockpit) (conn 2, pin 2) to component N10/11 (Passenger-side SAM control unit) (conn I1, pin 4)

9372: Cable from component X30/7 (Left CAN voltage distributor connector) (conn 4, pin 1) to component N10/1 (Drivers-side SAM control unit) (conn I13, pin 10)

These are intermittent problems and I do not see them all the time and 99% of the time the car is just fine.

I have inspected all of the connectors and SAM units and they all seem to be OK no visible signs of problems

I have a few questions:
Is it likely that poor electrical connection on these connectors could cause this problem?
Would cleaning connectors help?
Would it be sensible to replace the CAN distributor connectors for new ones?
Any other suggestions of where to look?

 

[shorty]

It migh be worth checking the left CAN bus bar, its located in the wire guttering along the front door opening , there may be a broke wire of a corroded connector .
The other bus bars are located under the dash on the passenger side and in the right hand wire guttering along the drivers door opening .
The CAN lines are brown / brown red wires twisted together .

 

[martyz]

How old is your battery? do the fault messages appear on initial start only?

 

[WG M-B]

Faulty sam causing that I would say.

 

[mickday]

Problem tends to occur after a period of driving and battery is less than six months old.

As mentioned the problem is very infrequent, last time it went at least 3 months between two occurrences of it happening.

I have inspected the connectors in gutters and also under passenger dash and they all appear OK no obvious signs of corrosion

 

[Dec]

Is the alarm working properly, what year is the car?

Dec

 

[mickday]

Is the alarm working properly, what year is the car?

Dec

Yes I have not had any problems with the alarm, car is a 2004, 805 build

 

[Dec]

Have you tested it… http://www.mbclub.co.uk/forums/electronics/169666-w202-how-test-car-alarm.html

The are known to be troublesome when the are about 10 years old and can cause all sorts of weird faults.

Dec

 

[golf2]

Did you ever resolve this problem?