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Mike, Mercedes Technician
Category: Mercedes
Satisfied Customers: 39198
Experience:  Tech Expert
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Hi,I have mercedes c270cdi year 52.Automatic got stuck in

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Hi,I have mercedes c270cdi year 52.Automatic got stuck in one gear,took to a mechanic he changed sensor plate oil filter and oil.worked good for 1000 miles got stuck again in one gear took car back and is diagnosed with p1664 electric heater booster open circuit p0199 mass air flow sensor voltage below threshold.
p2602 the voltage supply of the valve is faulty
p2600 the voltage supply of circuit 87 has under voltage.
I am told to take to a good electrician
can these fauls be diy as I can notafford to spend any more money on this car.
Hello and Welcome..

My name is XXXXX XXXXX Im happy to help you..

The first thing to mention is that the codes you have there do not relate to any issue that would cause the van to stick in a gear... they are then, most likely, historic.

The way to carry out fault code reading is to read the codes - make a note of them - then delete them with the machine. Re run the vehicle - then re test - see what codes if any you have then. You know then that they are current - not historic.

Too though - it sounds like the fault code test has been done -and only done, on the Engine management system - it needs to have the TCM tested - the transmission computer system checked / tested for fault codes.

A lot of aftermarket / garage equipment will not even give you that option - you may have to use a MB machine or dealer lever... Evidently there as above, you dont have any transmission related fault codes - so that is the way forward now.

Once you have the fault codes, for the transmission system, that will direct you to the cause of the faults you have ( stuck in gear ) and get this sorted for you -so thats the way forward on this one now...

All the best - MIKE.

Please do click on the "OK rating to Excellent ratings" service for me now, Thank you for that... and you can get back to me anytime if you need / wish..

Best Rgds, MIKE.

Please note, you are rating the content of my "answer" - my help to you - not the "system" which can experience delays etc which are not under my personal control -or delays caused by "time -off" which we all have on occasion - Thank you.
Customer: replied 4 years ago.


This is not a van it is c270cdi automatic car.Every time it is stuck in gear it is costing £50 to take it to a garage to clear the fault and get it running.

I have noticed that if I use heater or heating seats the problem starts car gets stuck in gear and @ 2500rvm it would do 40 m.p.h max.

Every time I am told by different mechanics not enough voltage on valve.

Problem is Heater

Hello again

Thank you for your reply. Forgive the typo.. Van / car... the info I have given you above is for the car in question.

The fact that you mention you feel its connected to the use of the electrics ( seats heaters etc ) would tend to indicate that you have a fault in the power / electric la circuit - causing whats happening... this can indeed do this... but it can take some finding especially if you are not using diagnostics. Basically an extra pull / draw on the electrics that causes this as you say, can be anything from a bad earth somewhere / bad connections to the various components, or even a fault in the battery / alternator charge circuit - whereby the extra draw when switched, causes the anomaly you have. Now that too note, would tie in with your latter comment - ie, not enough voltage on valve...

I wasn't aware of this info before - but given that - does add up then to all that I have just stated above - so that then clearly gives the direction to be working now to find / cure this issue.

Obviously I cannot do the work, I can only advise, based on the symptoms you outline - so that is what I have done with the added info above - and your way forward now to get this sorted ;) Its a case / best advise , would be to find and use a good auto electrician to sort this for you... as they have the knowledge and test equipment to go through the circuits to see why this is happening.

Kind Rgds - MIKE.

.................Please do click on the "OK/ Excellent ratings" for me as that's how Im credited for helping you - Thank you in advance for that...

You can and are most welcome to get back to me anytime you might need - clicking the OK ratings does not close you out at all..

Rgds, MIKE.

Mike and other Mercedes Specialists are ready to help you
Customer: replied 4 years ago.

you are not digesting my question at all.I am already advised by garage as i stated that take it to good electrician.

but in the forum it says that this fault is common so I asked the question if you know any cure,as I can not afford to pay electricians to re diagnose the same thing.

If you that code tales you were which loop to look up for I would appreciate.

If you could please discuss with other mates they must have come across this question before as I read a lot of discussion about it but no one has posted any correct answer.

I an sorry you might think or swear at me but that is what I am expecting.

Customer: replied 3 years ago.

The electrician could not get to the bottom of it