I just purchased those 4 wired sensors listed on the website. If you click on it, it will not show up because the item was sold. Sorry about that.

With the two ramps on the rear wheels and being under the vehicle with my back on the ground,I am having a hard time trying to remove the the left wheel speed sensor located above the differential and there is very little play to remove the screws/bolts. Is there a better way to remove the ABS left wheel speed sensor? Some say removal of a so-called trap door located under the back seat to get access to the top of the differential. Others say to have a lift ramp above the person's height and standing up to access the sensor. Any ideas? Also, where is the location of the ABS rear right speed sensor? I tried to follow the connector to the other end but due being on my back and cannot see where the darn thing goes to. Comments/ feedback is appreciated.

Here is the picture of the four end connectors with the black plastic knobs along with 2 ABS/ASR rear wheel speed sensors and 2 electrical connectors (Wire harness?)The image is the very first on the left side is the correct one with the plastic knob.

https://www.google.com/search?q=Wire+Harness+1245402117+1245402217+1245435726+1245435826&rls=com.microsoft:en-US:IE-Address&rlz=1I7PRFF_enUS553&biw=665&bih=408&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjUvcj81ffJAhXF0iYKHU4YBHwQ_AUICSgD[/IMG]

In regards to the code flashes 4=Air injection system faulty hot film mass air flow sensor with hot wire, the MAF sensor was cleaned with MAF cleaner, both inside the MAF and its connector. I cleared the diagnostic codes by disconnecting the negative cable from the battery for about 30 minutes. I then reconnected the negative cable to the battery. The diagnostic codes are now clear on the self-diagnostic module.

Next step is to remove the stripped 6mm screw/bolt from the front passenger side ABS/ASR wheel speed sensor and clean the sensor.

Here are the pictures of the abs/asr rear wheel speed sensors/electrical cables and their part numbers, along with the connector knob

Attached Thumbnails

       

I finally got the 6 mm screw/bolt (stripped) removed from the right side front passenger wheel speed sensor and replaced it with a new bolt/screw. I cleaned the wheel speed sensor. The ABS/ASR lights still show on the instrument cluster panel after driving 3 mph. Next step is to removed the four wires rear speed sensors and hopefully this will end/resolve the issue.

I am going to a shop that has a "pit". This pit is like a underground solid concrete walk through under the vehicle without the lifts. That way, it has more accessible and easier to maneuver to get to those darn wires and removal, hopefully. Supposedly I am set up to go to the shop this upcoming Thursday, and I will update my progress.

I went to the shop today. The pit was flooded. Had to wait until dried next week

I decided to take my E320 wagon to another shop nearby today and have the knob connector with the 4 wires (2 ABS speed sensors and 2 electrical) replaced with the one I bought earlier. My reasoning is safety and I don't feel comfortable working inside the pit, even though the pit will not be available for several days due to flooding and the time to dry out. Also, eliminating making mistakes on my part and possibly breaking bolts. At least I will have peace of mind.

After waiting several hours at the shop while the mechanic working on the wagon, I finally drove the wagon home today without the ABS/ASR warning lights on in the instrument cluster panel. In fact, the drive was smoother and the braking was great as well. No skipping and/or pulsating as I floored the brake pedal and it was smooth as well. Problem solved!!!! The fact was that originally the Rear speed sensor was faulty along with the broken electrical wire in the diagnostic test was correct. I was concerned about the possibility of false diagnostic in the first place. My only regret was not able to finished the job myself. After carefully reviewing my options and concerns for my safety, I made the correct decision by having the mechanic to finish the job. My long nightmare is over for now. Who knows what else might pop up? I don't want to think about it. Thank you to all who wrote comments about my issue and reading this post/thread.

Update: The same issues pop up again. It has been quite awhile since the last time. Will follow up and update while I try to resolve this issue again.

The technical article do it yourself regarding the ABS/ASR warning lights on the instrument cluster panel is: https://www.pelicanparts.com/techarticles/Mercedes-W124/71-BRAKES-ABS_Sensor_Replacement/71-BRAKES-ABS_Sensor_Replacement.htm

Hopefully, the technical article will help.

I checked out the two ABS relays on top of the ABS hydraulic pump with ASR. I removed both ABS relays and inspected them both. No sign of dirt, rust, clear contacts. However, the 4 pin ABS relay when I shake it, I felt something was loose, nothing solid. The other ABS relay 6 pin, nothing felt moving inside.

Also, I started the engine and few minutes later, the ABS and ASR lights on the instrument cluster panel came on. I pressed the brake pedal. At first, solid traction about 6 inches above the floor. Then slowly, (already pressed brake pedal) went down to the floor. In addition, the rear brake lights were on and stayed on, even though I did not pressed the brake pedal.

I use the technical article below as a guide and troubleshooting the ABS/ASR light on issues.

https://www.pelicanparts.com/techarticles/Mercedes-W124/65-BRAKES-ABS_Relay_and_Pump_Replacement/65-BRAKES-ABS_Relay_and_Pump_Replacement.htm

Any comments from anyone? Stay tune for further updates.