I have a 2003 Mercedes SL55 with ABC Problems

December 2012

- I received the white ABC Drive Carefully warning and right away connected the DAS to the car for a full diagnostics. After, conducting a full diagnostics (RODEO) I noticed that the pressure dropped below 100 bar.

- The car was not leaning. I drive the car almost everyday therefore it never is parked for the long term leaning to occur as I have read on the forum.

- The white warning light would go off and come back on intermittently.

January 2013

- I ordered a refurbished pump and replaced it.
- At the same time I rebuilt the valve block
- Put a new filter and ran the RODEO, put in another new filter and ran the RODEO, this process was recommended vs flushing the system and putting new fluid
- Topped of the fluid to reach lowest mark on dipstick on a warm engine.

- Car ran great for about 1k miles

April 2013

- I took a 150 mile trip and the ride was great. Parked the car and when I came back I noticed there was fluid on the ground which looks like it came from the reservoir. I opened the hood and noticed that the level was correct. I started the car and drove it home one mile. Then checked fluid again and it was at the correct mark. However, there was a Red ABC Drive Carefully. Once I came home I connected the DAS software and noticed that the ABC Pressure is 4 bar.

- At this point, I took the stethoscope and noticed that the pump is running with what sounds like normal operation (no abnormal grinding).

- The power steering works well and all of the fluid levels are where they should be based on the engine temperature.

Now, I'm looking for advice please let me know if it could be the pressure sensor. I have been traveling lately and have not had time to work on the car. I'm open for any suggestions which would indicated what the cause of the pressure drop would be?

- I have researched a bit and I'm positive that the pump did not run dry and the system is fully pressurized since the car is not dropping/leaning.

Could it be a leak in the system where air bubbles are being introduced into the system?

I plan on putting the car on the lift this weekend to take a closer look for leaks and a full inspection of the pressure sensor.

I appreciate any input/advice you might have for me and thank you for reading through my troubles with the ABC System.

 

BUMP... Debating if I should take it in to the dealer for a full diagnosis... Let me know what you guys think

 

do a rodeo and post here the abc system pressure psi graph... you can also do the tandem pump stress test and post the graph here.

you either have gunk in the system, bad pressure sensor(s) or something else or the planets are not aligning properly on a leap year ...

the abc fluid reservoir will overflow if you have pump problems (not pumping). the abc system has certain back pressure and if the pump is not in good order the backpressure will push fluid back through the pump into the reservoir and overflow it.

one thing to try is to leave your car for a day or two and see if it leans on any corner. this might give you more info on what is going on.

 

Alx,

Thank you for all of the information, I believe that the planets were not aligning properly on a leap year because when I turned on the car today the pressure was back to 189 bar.

I will lift the car this weekend and inspect it for leaks. I also set the car to lowest setting (normal) and will leave it until the weekend. For the last couple of days it was in the highest setting and I could not notice any leaning on any of the corners.

Also, I was able to do a rodeo and now the pressure idles at 189 psi and during rodeo it dropped to 119 psi but after it was complete it went back up to 189 psi rather quickly. I also captured a pressure graph but was not able to do the rodeo so it just shows the car idle between 188-190 then when i turn it off the pressure drops. I'm not sure on how I can capture pressure and do the rodeo at the same time.

I also took some time to listen to the pump again using the stethoscope and could not detect any irregularities. However, I did put it on Spark Plug wire connector #2 A and noticed a loud rattling that was not present on any other spark plug wire metal cap. Any ideas?

 

the pressure will drop during rodeo and once it is below 100 rodeo will stop until pressure is built again and then will resume. if yours never drops below 120 i assume your pump is in really good shape. most abc cars will stop several times to build up pressure during rodeo.

in regards to leaving the car in the top-most position- the top most position "locks" the valve blocks in the most favorable position so if there are any leaks it will be harder to notice (ie little to no drop). best is to leave car in lowest position (like you did) to see if it dips in one of the corners...

the rattle near #2 - i have no idea. the v8s are very vocal and like to chatter/ click/ clack a lot. valvetrain is noisy to begin with. if you have a particularly noisy spot... it could be valve clearance. i wouldnt bother though unless it gets really noisy.

 

What kind of diagnostic tools are you guys using to perform these checks and "RODEO"? I recently had my control arm bushings replaced and now the light is on the dash (I think white). I never realized there were two different colors before reading this, but I think I have seen red in the dash. I also have a noisy pump or damper I need to fix on this car. Thanks for any help you can provide.

 

Please search the forum for das, xentry, star, multiplexer... Etc.

Plenty of info on the subject.