Posted by Gerald Devine on March 27, 2012, 11:36 pm
Year of Manufacture *: 2004 Facelift model
Hi,
I have a Mercedes W203 CDI with a gear selection fault. After driving a short distance the vehicle will stick in a gear (which ever gear is selected when the fault occurs). After the fault occurs, and with the vehicle stationary , the gear selector can only be moved from drive to neutral. The winter / standard driving modes can't be changed while the fault is present. When the engine is stopped and the key removed the gear shift will move freely through reverse to park. Once restarted the gears can be selected normally and the vehicle will drive a short distance before displaying the symptoms again.
When the fault is present and the vehicle is in drive if I move the shift to neutral or try to move to the tip tronic (manual shift) D will remain illuminated in the display dispite N being selected.
I have checked the codes on my auto diagnos P1856 Gear selector fault. I would appreciate some help from the Mercedes experts.
can auto diagnos do live data in transmission have replaced a few shift units on these are the brake lights working,the switch has two jobs & one is to provide the selector assay with brake pedal position I would def use live data to check brake pedal signal & gear lever solenoid actual value hth,keith its very strange that you can move the lever without key in? that def shouldnt happen
Thanks for the response. I cant view the live data in the transmission system and the brake lights are working. I had a look around the wiring today and I found some transmission oil in the multiplug at the gearbox. I cleaned it out and took it for a test drive, It appears to be going ok! Fingers crossed! I have spoken to Mercedes and apparently there is a modified sleeve that cures the leak.
If you have found oil in the electrical connection at the front of the gearbox, then its probably worth checking for oil at the block connectors for the gearbox control unit, which is normally in the passenger footwell. Have had these fill the control unit up with oil before. hth Nev