CLS350 CDI 7G Tronic (722.9) cold start problem - No Manual Mode

Discussion in 'CLS-Class' started by mmaarrttoonn, Feb 18, 2017.

  1. mmaarrttoonn

    mmaarrttoonn New Member

    Hello Everyone,

    I've just bought a 2013/10 CLS 350 CDI Shooting Brake 4Matic.
    It has around 80.000 km, all services undertaken by Mercedes at 25k, 50k, 75k.
    The car has the Transmission mode selection option: E - Economy, S - Sport, M - Manual.

    The last 3 occasions when I started the car first in the morning and went on driving:

    - Cold weather (0 to -5 Celsius at night, around 0 Celsius during the day)
    - The Transmission switched every gear at exactly 2,900 rpm (which is rather high), which might be OK for the first 5-10 minutes, however...
    - It kept switching gears at this rpm even after 30-40 minutes constant driving, with the engine already being warmed up
    - The Transmission mode M - Manual cannot be selected (the car allows E or S mode only), however...
    - I can change gears with the flaps on the steering wheel, but only at high rpm-s.
    - By shutting down and restarting the car, all of the above problems are gone, smooth and perfect shifts, M - Manual mode can be selected. Like nothing happened.
    - These happened only after the first start in the morning, the symptoms went away for the rest of the day (no matter how many restarts).

    I haven't been to a service to have the problem checked yet, I thought to give it a try here on the forum, someone might have useful info on this/had same issues.

    Any ideas appreciated.

    Thank you
  2. Kajtek1

    Kajtek1 Awesome Member

    When those cars have program to keep high rpm for engine warming, your description indicate more than normal behavior,
    Check codes and report back.
  3. mmaarrttoonn

    mmaarrttoonn New Member

    The problem persisted as days passed. Finally two days ago, the car put itself in limp mode without any error message.

    Yesterday I towed the car to a technician. When I parked the car on the trailer, the yellow check engine light came up finally.

    Error code: 159300 - Internal failure in part B60 - Exhaust back pressure sensor. I am waiting for the part to arrive to the shop (this afternoon).

    I took off the engine cover and found oil around the tube that delivers air in to the turbo (including the B60 part which is right next to the turbo). Since the oil was around this area I took off this tube. The tube has a rubber O-ring in it. This should slip on the tube of the turbo. The latest service was carried by Mercedes-Benz in Frankfurt. The fuel filter was replaced under this service. In order to be able to replace the fuel filter, you have to take off this tube from the turbo. I attached a picture showing how the guys in Frankfurt are working. The O-ring was crinkled. I think this caused the leakage of the oil, which was spitted on the sensor and this caused the failure of it.

    In the mean time I found a topic where someone had the same issue (the symptoms described in my previous post), and after 8 months and several service visits, the replacement of the exact same B60 component solved the problem.

    The source:
    (Description of symptoms first post, solution last post.)

    I will report back after the B60 part replacement.

    Attached Files:

  4. mmaarrttoonn

    mmaarrttoonn New Member

    Problem solved. Car runs flawlessly.
    Check engine is still on. I guess the stored fault code have to be deleted.

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