My husband wrote the following. Any information would be appreciated.. We are currently about 2.5 hours South of Agadir. We are attempting to contact Sudstar Auto in Agadir to see if they can assist us.

My wife and I are traveling through Morocco and hope to head further south into Western Africa with our 2018 144” high-roof 4X4 Sprinter:

At this point, I’m don’t think we want to proceed without at least understanding the issue below or fixing it.

Two days ago, we got these three amber warning lights on the dashboard: ABS, spinning wheel (ASR/BAS), and swerving vehicle (ESP). After a while, we also got a solid amber "check engine light”.

Other than the cruise control not working, everything else seems normal.

Our UltraGauge ODB2 reader stated that the engine code was “C003A”. An internet search seemed to say that the right rear wheel speed sensor was at fault.

This confirmed my gut suspicions as to what (wheel speed sensor) and where (right rear) since we have had two instances in Iceland and Germany where the rear right wheel has been spinning in river gravel during a water crossing and in a muddy ditch, respectively. Each of these instances caused damage to the tire’s valve stem.

At this point, I was hoping a thorough cleaning of the wheels and undercarriage would alleviate the problem since we had just crossed the High Atlas Mountains over a few days and 200 miles of dust, dirt, mud, and snow. After a high-pressure wash, the lights remained on.

The next day, I broke out our iCarsoft MBII and it notes: “CAN bus - CAN signal 'Rear right wheel speed' from control unit N 30/4 (ESP control unit) is missing or faulty.”

Next, I located the sensors and disconnected the closest connectors that are attached to the body/chassis just forward of the rear axel. At each connector, I measured the voltage at about 12.0V coming from the electronics side of the connector (side going towards the engine bay to the control electronics). Knowing nothing more, this indicates that the wiring and electronics from the Sprinter are ok.

Now, it was time to focus on the sensor side. In doing internet research on the issue, it seemed that the wheel speed sensors could be Hall effect and not the old-school, simpler magnet type. So, I did not and have not “Ohm'ed out” (measure the resistance of) the sensors.

Next, I decided to take the wheel off and clean as mush as I could without doing any “invasive” disassembly. I was able to disassemble down to the rotor and parking brake shoes.

At this point, I was a bit surprised to see that I was unable to get down to the “tone ring”. This is the gear-shaped ring that coupled to the old magnet-type sensors. The sensor on our Sprinter seems to be included in the “hub assembly” for lack of better terminology. I am not up to the task of taking it apart further without more information…

After pulling the wheel speed sensor, I was able to somewhat clean the "spinning part” (analogous to the tone ring) with Q-tips down the sensor tube. I also cleaned the sensor and added back new, clean Lithium grease. We also inspected the sensor cable and all looks “like-new” with the exception of road dirt on the cable.

After reassembly, I was able to clear the codes for several miles. After a subsequent engine re-start, the warning lights all came back.

Now, what to do next…

It is not clear if we can get a “full service” Mercedes dealership and repair facility in Morocco. Even if we can, I’m not sure what the real issue is - sensor or “tone ring”.

What I would like to do next is to swap the left and right sensors. My thought is that if the control electronics now say the new left sensor is at fault, the current right sensor is to blame. If the error remains on the right, the right “tone ring” can be to blame. I have not tried this yet.

Here are my questions:

1. Are the right and left wheel speed sensors the same?
2. Are the speed sensors indeed Hall effect-type?
3. What is the “tone ring” called?
4. What is the rough procedure for getting at the “tone ring”?
* Looking for things like: "take out the axle", "disassemble the hub", etc.
* I want to know if this is something I want to tackle in a small town or the bush.
5. For you experienced Sprinter mechanics, is this likely a sensor or “tone ring” issue?
6. Also for you experienced Sprinter mechanics, is a cleaning of the “tone ring” likely to fix the issue?
7. Is there anything more I can do to troubleshoot this?
8. Is there a wheel sensor check procedure?
9. Anyone know of a good Sprinter mechanic near Agadir, Morocco?

I have learned quite a bit on this forum over the last year and a half while building up on vehicle. In fact, I have mostly been able to answer my questions just by reading the archives and not needing to post. So, thanks for all your help!

Thanks,
Ryan

Attached Thumbnails

 

That's a whole load of info

You've seen the sticky post in this section on where to get repairs? lot of good options listed their. I posted details in that thread about a Turbo Repair place (I realise the turbo isn't this issue) Aziz who runs it is very helpful and speaks good English so might be worth a call to see if he knows who can help. He also has connection with Ali Nassir in Zagora

Hi Ryan:

I'm not familiar with Mercedes products, but I am very familiar with Volkswagen products, and they use a very similar system for ASR, ABS, and ESP.

My suggestion is that you just ignore the problem until you get to some location (perhaps a big Moroccan city in the north, or perhaps even back to Europe) where you are comfortable and confident that you can get the problem fixed.

There is nothing mechanically "wrong" with your vehicle. As you have determined through your own investigations - and it sounds like you know what you are doing, and what you are dealing with - you have suffered a loss of functionality of the above-mentioned safety systems. That's all.

Before I retired, I was an aircraft pilot and aircraft maintenance technician. All large aircraft have what is known as a "Minimum Equipment List' (MEL). When a component or system fails on an aircraft, it doesn't automatically ground the aircraft. The pilot looks up the failed system on the MEL, and the MEL provides guidance about whether or not the aircraft can continue to be safely used with the inoperative component or system.

If your Sprinter was an aircraft, I suspect the MEL guidance for your particular system failure would look like this:

"Vehicle can continue to be operated until reaching a service facility, but anti-lock braking, stability control, and wheelslip regulation will not be available. Avoid operation on sandy or slippery surfaces, and be aware that one or more wheels may lock up if hard braking force is applied."

In other words, take note of your failure, don't go down roads that you wouldn't travel on with an ordinary passenger car, and be aware that you no longer have ABS protection. But otherwise, continue your journey as normal.

Michael

I'm with Michael - just drive round it until you get to a place where it can be sorted out at leisure. I've had similar issues with my Land Rover over the years and while it's nice to have these features they're not trip ending if they go wrong. It would be an MOT failure in the UK but as long as you're not heading for a test centre and there's no mechanical failure causing it fix it later.

As the OP says the intention is to continue south, just "driving it 'till they find somewhere better" might not be an option - Namibia? I would guess running back up to Casablanca would be a better bet.


http://www.autonejma.ma/

Better to back track to a Merc specialist than ploughing on south, worrying all the way if it's going to get worse.

Get it sorted now, lose a couple of days and enjoy the rest of your trip.

Happy trails,

Peter

__________________
Atlas Overland - Specialist adventure tour company providing off-road holidays for 4x4 enthusiasts in Europe and North Africa.
Tours to Morocco, Iceland, Arctic Circle, Portugal, Alps, Pyrenees, Eastern Europe, Corsica, and UK weekend tours.

hello, there's a big new Merc dealer on the Casablanca road in to Marrakech , got back from a round trip to Gambia at the end of Feb, my 1989 ,208D never missed a beat, no sensors no problem. exhaust broke in half in Senegal ,but Zebra bar got me going, then again in Spain, but GumGum and jubilee clips got me home. good luck. regards chris

I guess with a modern 4x4 you should bring your own advanced OBD2 scanner to Africa?
One traveller had to abandon his fairly new Range Rover in Agadez only with electronic issues...
Related to this, a cousin of mine runs a garage in Chico, California, specializing in older cars Mercedes wont accept for repair - meaning those more than ten years old.
Some have what appears to be only minor faults, but can't be driven. Changing components identified as faulty by thé scanner sometimes doesn't help.
He said the industry standard for the harness connectors is they should hold up being taken apart and put together six times.
Six times. That's all.

Gratulation for solving the issue!

I did carry a Notebook with the Toyota Techstream software and USB Dongle with me, when I did the Transafrica and while travelling in south america.

Driving with an modern 4x4 in remote areas - could made that to a valuable gear.

I did just use it for resetting errors, what happens twice in Africa - not in south america. But if something would go wrong, I can phone to my european mechanic and try to solve or troubleshoot issues.

Getting spares abroad need extended time abroad, too if you ask a toyota mechanic. 60 Days fright, 40 days Express Airfright was named severall times. With Toyota many Parts are "on Stock" to be honest, but at sample an european model has severall stuff equipped what a car in Africa/south america dont have. (2nd Aircon, 2 batteries, same kind of diesel particle filter and so on..)



Here I wrote down my experiences, how to get spares abroad:

https://www.4x4tripping.com/2015/04/...weltreise.html

In my eyes everytime something can go wrong, but it rarely does. I wish you luck on your further trip - hoping that (c)ovid restrictions get solved!

Surfy

__________________
About Overlanding, Travelogues, Equipment
Trans-Africa over the west coast