05-22-2013, 07:46 PM
Date registered: Dec 2011
Automatic transmission clicking noise
First, thank you for taking the time to read this posting. I am new to repair of mercedes, but have been repairing vehicles for the past 20 years.
I own a 2004 Mercedes A168 with automatic transmission (model 722.7). The car transmission has started to make a clicking noise while driving at the time when transmission is switching from gear 2 to 3. The noise is similar to electric contactor switch that is not working. Also:
- the shifting from gear 2 to 3 is not fluid - most of the times, there is the clicking noise. At other times, the gearbox successfully shifts into 3rd gear.
- the engine seems to lose power at the time when the gearbox is trying to shift into 3rd gear, slowing the car down.
- shifting gears from 1 to 2 and 4 to 5 work just fine, no noise
I have had the car diagnosed with software DAS Xentry which suggests there is a fault with FGS, citing Y3/7n2, Y3/7n3 modules fault codes from #2000 through 2009. Other codes were 200B. I have had the Y3/7n2 and 7n3 parts replaced, but the noise persists.
What could this be and where should I look? I am clueless.
Many thanks for your wisdom,