ABC symptoms at idle - SL55

[Lowe712131]

Hi all - have got some major work planned on the ABC system on my SL55 - valve block overhaul (x2), new accumulators, 1 x level sensor, fluid, filter etc.. but the only item I'm not (currently!) replacing is the Pressure Relief valve block. One of the symptoms I'm getting is an occasional 'jumpiness' when sitting at traffic lights etc - not as bad as a rodeo, but just small movements in the struts when I come to a stop - to me, that sounds system pressure related? Any thoughts? Pump is good and pressure at standstill seems pretty constant, around 190bar.
Also, I will be buying a job lot of O-rings for the ABC valve block job, so if anyone else needs some, I will be able to put a few sets together. Watch this space.
Simon

 

[television]

This is something I have never heard of before, since all the level sensor go back to the ECU under the dash next to the gearbox ECU do clean the connections on the two connectors, there could be near on 100 pins between the two plugs, use a non drying switch cleaner, I had faults on mine, and it fixed it.

 

[Lowe712131]

ABC

Thanks Malcolm, yes, I have suspicions about the electrical connections in that area - there are a couple of other glitches that point to that area, have ordered some new Canbus connectors too. My STAR is struggling to talk to some of the ECU's, all of which point to that connector under the drivers side carpet (notably the diagnostic ecu plugs into the canbus connector there. I have suspicions of water ingress in that area, so I'm actually hoping to find the green death on the connectors, will answer a lot of questions! Just need some decent weather and some time to do it.
Thanks Malcolm.
Simon

 

[television]

Have you ever cut the flaps off the heater drain pipe under the nearside rear section of the front wheel arch liner, this is where the water comes from and into the sill. CAN bus signals carry no current and cannot arc themselves better, again a good non drying switch cleaner will sort it

The brown/ red can wires are for the things in that block, the black/red are the inter links from the 3 CAN blocks so easy to isolate problems further back.

The blue/ white right up front are the wake up that also join in.

 

[Lowe712131]

Thanks for that, I'll have a look at the drain flap - the heater drain isn't holding water but that's not to say it hasn't in the past. I'm actually hoping there is a water leak down there to be honest - will be a massive clue as to the source of the problems.
Cheers
Simon

 

[television]

The problem here is the sill pockets are well below the floor level, the passenger seat has to come out to be able to get to the cable trunking.

 

[television]

If you are worried about any CAN fault you can access the connector in the rear box behind the seat, a simple voltmeter will tell you if the CAN is running in the high and low mode or just a single wire.

I have the voltages if you want to check, it will also tell you if the wake up is OK and the going to sleep.

 

[Lowe712131]

That's great Malcolm, thanks again. I'll give you a buzz when I'm going to have a look - I've got a scope meter so will have a look at the voltages, nice one
I'm new to the Canbus stuff so I might call on you at some point for test point locations etc.. Thanks
Simon

 

[television]

I can give you everything that you need for info for the CAN bus and where everything is on a 230 including all connectors, just no problem.

 

[Lowe712131]

Hi Malcolm - just a quick question, is this the sort of non drying switch cleaner you would recommend?
http://solutions.3m.co.uk/wps/porta...5230GE3E02LECIE20KAJ2000000_c=LongDescOutlink
I have some normal contact cleaner, but I guess the silicon film would be of benefit for non-current contacts? - electronics not my main bag! .... Yet!
Cheers
Simon

 

[television]

The will do just fine .

By nondrying it leaves some residue film behind, if you spray some on your finger it does not evaporate

 

[Lowe712131]

Nice one, thanks again