2012 CLS 350CDi Gears not changing

[Pritesh]

I have an issue for the last day or two when driving the car does not change gears until around 2900RPM, I cannot manually change the gears and the engine management light has come on. I have got the following fault codes that have come up on a SnapOn computer.

Anyone experienced this issue and what was done to resolve it?

100D00 - The Lower Limit Value Of Component 'b2/7 (Right Hot Film Mass Air Flow Sensor)' Has Been Reached.
100E00 - The Lower Limit Value Of Component 'b2/6 (Left Hot Film Mass Air Flow Sensor)' Has Been Reached.
101500 - The Lower Limit Value Of Component 'b2/7 (Right Hot Film Mass Air Flow Sensor)' Has Been Reached.
101600 - The Lower Limit Value Of Component 'b2/6 (Left Hot Film Mass Air Flow Sensor)' Has Been Reached.
120D00 - Component 'y77/1 (Boost Pressure Positioner)' Has A Short Circuit To Ground.
121500 - Component 'm55 (Intake Port Shutoff Actuator Motor)' Has A Short Circuit To Ground.
161400 - The Signal Of Component 'b2/6B1 (Left Intake Air Temperature Sensor)' Is Implausible.
161500 - The Signal Of Component 'b2/6B1 (Left Intake Air Temperature Sensor)' Is Implausible.
161700 - The Signal Of Component 'b2/7B1 (Right Intake Air Temperature Sensor)' Is Implausible.
161800 - The Signal Of Component 'b2/7B1 (Right Intake Air Temperature Sensor)' Is Implausible.

We have cleared all the codes taken the car for a drive and the following have come up. It seems to be pointing toward the Mass Air Flow Sensor. However, its not a cheap part, Mercedes was over £500 for it and want to be sure it is this and not anything else before splashing that kind of money.

We have disconnected the Mass Air Flow Sensor on both sides and driven the car which made no difference.

Any help appreciated.

 

[Dodipops]

There is an air mass balancing procedure you can do using star or decent diagnostics, check the obvious before hand though, ie air filters and intake ducting pipes.
The inlet port motor are problematic as well especially if oil is leaking through the turbo intake seals and leaking on to the inlet motor. Should also be able to actuate this through diagnostics.

 

[OneForTheRoad]

The gears wont work when the engine is in limp mode.

 

[Dodipops]

Often when in limp the box won’t change or is slow to change due to a loss of torque so the ecu recognises throttle position to torque demand and notices an incoherence and delays shift changes to compensate.

 

[Pritesh]

Thank you very much for the info. There's breather oil around the seal between the mass air flow and the turbo. If its the inlet port motor is seems a bit of a pain to get to. I've booked it in at Mercedes Coventry its going in tomorrow morning hopefully they will be able to determine the actual issue fingers crossed. Its annoying I just want to get it fixed.

 

[OneForTheRoad]

Thank you very much for the info. There's breather oil around the seal between the mass air flow and the turbo. If its the inlet port motor is seems a bit of a pain to get to. I've booked it in at Mercedes Coventry its going in tomorrow morning hopefully they will be able to determine the actual issue fingers crossed. Its annoying I just want to get it fixed.

Goodluck.

 

[Mr Filipov]

If going on the error codes alone, the one that will cause limp would be the inlet shutoff motor to my knowledge.

I had a car with a duff MAF and that did not cause any issues for over a year, until I discovered it was gone for some time.

Not sure if air intake temps can cause limp, but someone with more knowledge should be able to confirm that.

 

[Pritesh]

I have had Mercedes in Coventry take a look at it and they are saying I need to replace the turbo as the turbo actuator has seized plus replace that inlet shutoff motor, only after that has been done will they be able to tell if the MAF needs replacing. The costs are eye watering

 

[OneForTheRoad]

The actuator can be repaired or replaced with a used unit. Also the swirl flaps can be over ridden using a 10p resistor. Which is what id do then sell the car on.

 

[Pritesh]

I'm going to get it repaired by an independent garage. Don't want to sell the car on only had it just over 6 months and loving (well not the repair bill).

 

[Pritesh]

Quick update - As I said I ended up taking the car to a Independent Mercedes Benz Specialist. The issues I was having was due to a seized turbo actuator and the inlet port motor failing. As a result you cannot just replace the turbo actuator the whole turbo has to be replaced, mine was reconditioned and a new inlet port motor was fitted. The car is now back to life thanks to Andy Galye of Smethwick.

 

[Peter103]

Hope you managed to save a few shillings over what MB Coventry were quoting?

 

[Abb]

Quick update - As I said I ended up taking the car to a Independent Mercedes Benz Specialist. The issues I was having was due to a seized turbo actuator and the inlet port motor failing. As a result you cannot just replace the turbo actuator the whole turbo has to be replaced, mine was reconditioned and a new inlet port motor was fitted. The car is now back to life thanks to Andy Galye of Smethwick.

Good to hear you got it sorted

I would interested to know did they tell you what caused the issue in the first place and if there is anything you can do to prevent it occurring to begin with or to prevent it re occurring in your case?

I have recently purchased a the same model car, hence my interest.

 

[Pritesh]

Good to hear you got it sorted

I would interested to know did they tell you what caused the issue in the first place and if there is anything you can do to prevent it occurring to begin with or to prevent it re occurring in your case?

I have recently purchased a the same model car, hence my interest.

What I have been told is on the 350 diesel engines its pretty common, the main problem is if its used for short distances then the engine does not warm up fully and this can cause it. I did ask the garage what can be done to prevent/prolong the life of the turbo and to which there is no real answer to as its very hard to say why each and every turbo fails. I am hoping this will be last of my worries for the turbo now.

 

[Mr Filipov]

What I have been told is on the 350 diesel engines its pretty common, the main problem is if its used for short distances then the engine does not warm up fully and this can cause it. I did ask the garage what can be done to prevent/prolong the life of the turbo and to which there is no real answer to as its very hard to say why each and every turbo fails. I am hoping this will be last of my worries for the turbo now.

The problem actually comes from the following item. The seal that sits between the intake pipe and the turbo. The rubber seal tends to perish over time, and owners as well as MB themselves tend to overlook that part. In itself it’s a £20 seal from Mercedes which is dead easy to swap over.

As it perishes it lets oil seep out and it goes directly in the V of the engine, conveniently where the inlet shutoff motor is located. It is the collection of oil that causes the motor to fail and leads to a big bill. If you change the seal every other service that will prevent any future aggravation with this item failing again.

As to what causes the turbo actuator to fail, I am not too sure myself to be honest. Hope this advice helps out a couple of people.

Here is the ebay link for anyone that is interested:
Genuine Mercedes-Benz OM642 Red Turbo & Breather Intake Seal Kit NEW | eBay