PeachParts Mercedes-Benz Forum - View Single Post

cleavster · #7 05-31-2020, 11:10 PM

Here are the latest updates....

After more testing and rechecking, the code reader came up with another code on the MAS controller - Code 2.

Code 2 - Fuel pump relay (circuit 87) not functioning

If this code was true, I would not have been able to start the car and drive around without stalling completely. At this point, I was convinced that I may have a failing MAS Controller. Also, Christuna suggested that this may be a problem too on a previous post.

Changed the controller and codes 2,3,5, and 13 were gone. These codes were replaced by another code.

Code 11 - A/C compressor engagement signal missing (87Z)

Will this code engage the CEL light? I may have a real bad A/C compressor at this point? As I mentioned I did not have any A/C for a very long time. I have a leak somewhere.

Now, the car does not hesitate and no issues so far. I drove the car for an hour on the freeway and around town. However, The pesky air injection pump Code 11 is still appearing on the CEL.

Here are my observations:

(1) The CEL light comes on when the vacuum cycle through not the first time but on the consecutive vacuum checks. For instance, I'm idle on a traffic light and then you can hear the pump and the CEL comes on.
(2) There is no back pressure on the Fuel Tank when I added fuel today. Usually, I will hear a vacuum sound.

The only components that I have not checked are the following:

(1) Fuel Tank Purge/Regeneration valve (107-470-08-93-M22) - this valve is connected to the throttle body, charcoal canister, and to a solenoid switch.
What is the best way to check this? Can I just pull it out? Not sure how it is all connected inside the inner fender.

(2) Air Pump Check Valve (000-140-78-60-MBZ) - this valve is connected to the engine. It requires a large wrench size and I'm not sure what is the best way to remove and test the valve. The wrench I have will encompass the two threads so you will not be able to place one wrench to go one way and the other wrench the other way. Hope this makes sense.

Any ideas on this one?

BTW, battery voltage is at 14.3V when running.