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With about 150K Miles on my '06 S430 I recently have had the dreaded "Visit Workshop" pictogram pop up about 5 minutes after driving. With my MBII Carsoft reader, the error number was C1144 noting a fault in the pressure sensor.
Fast forward, seems that the pressure sensor itself never really fails, but related components seem to trigger this error. After some research, he is the first component I looked at. The pressure solenoid valve mounted directly to the air compressor. Seem that the small actuator gets some corrosion overtime and gets a little sticky or stuck.
FIX 1:
Carsoft error screen.
The round cover over the solenoid is held by two torx screws
Here is where the solenoid is removed.
This is the order of the parts, the black part is the plunger with a rubber seal on the face of the flat end.
Dremel with a polishing bit and some metal polish will smooth out the bore of the solenoid body.
Remove all corrosion.
I lucked out, my car has the AMG cosmetic package and the front bumper cover has large grille openings. I was able to remove the right front lower corner grille and was able to do the repairs with the pump in place.
Tip: You can test the solenoid with 12 volts. To reassemble, use a jumper wires to power the solenoid to hold the plunger and spring in place during re-assembly.
FIX 2: Broken air line to the valve assembly - Port #5
Fix 1 seemed to fix the C1144 error for about 1 day, then it came back. After another inspection of the valve assembly, I found hose/tubing was pulled away from the fitting. It was for the air tank connection.
Port 5 broke off
Hose was intact but no longer part of the brass fitting.
5/32" brass tubing from the hobby store, this is the same diameter of the plastic tubing. I cut a short length and silver soldered it to original fitting. I removed the o-ring round the threads first.
About 1 year ago, I purchased some of this fittings from Ebay. The blue ends are push type tubing fittings and the silver with white cap is a 1/8" pipe connection with a block off cap. You can get unions that are not tee connections, but I figured I could add a small pressure gauge if needed.
Hard to see, but you can see the brass tube I soldered to the right of the tubing with the yellow colored identification. The union goes over the brass tube and the stock plastic tubing goes into the union.
08-12-2016, 09:14 PM
