BENZE220AMG Posted February 10 Share Posted February 10 I own a 2014 Mercedes CLA that exhibits an intermittent issue when the vehicle halts, approaches a stop, or accelerates from a standstill. The vehicle vibrates and displays a warning light; do not shift gears and contact a workshop. I must turn the vehicle off and then on again before I can resume driving normally. Today, while en route to the garage for a diagnostic assessment of the fault, I encountered an additional error message indicating a gearbox malfunction in red. This occurred when the vehicle was stationary and prepared to accelerate, causing the gearbox to shift into neutral. I subsequently re-engaged the car into Drive, and it operated normally. The issue is sporadic, which is somewhat vexing. The garage linked the vehicle to their star diagnostics, but no problem signals or codes pertaining to the gearbox were detected. The technician suggested that doing a software update, if available, may potentially resolve the issue before further investigation, given the diagnostics indicated no abnormalities with the gearbox. The vehicle has just reached 120,000 km and requires its second gearbox service. Any guidance would be welcomed, particularly from others who have encountered a similar issue. Quote Link to comment Share on other sites More sharing options...
Rudy7831 Posted February 10 Share Posted February 10 It is necessary to retrieve problem codes using the star machine. Common issues include wear in valve bodies and dual clutch units. Given the age of the vehicle, you should have completed three gearbox oil maintenance by now. Quote Link to comment Share on other sites More sharing options...
BENZE220AMG Posted February 10 Author Share Posted February 10 I appreciate your reply. The garage linked the star to it but detected no defects. The alternatives presented to me were to first verify for software upgrades next week and thereafter examine the valve body. They were astonished that nothing was revealed about the celebrity as well. Quote Link to comment Share on other sites More sharing options...
rab60bit88 Posted February 10 Share Posted February 10 It is certain that only MB STAR will do the task. However, if the garage proposed to execute a gearbox software upgrade, he would probably want a genuine MB STAR scanner. Did he propose that the vehicle be transported to a dealer for the software update? Generally, the common problems include inadequate service (a 2014 vehicle should have had the ATF replaced twice, first in 2019 and again in 2024) or a defective gearbox control unit (TCU). However, there may be further complications. Quote Link to comment Share on other sites More sharing options...
BENZE220AMG Posted February 10 Author Share Posted February 10 Thank you for your reply. The garage have the capability to do a software upgrade, since they are Mercedes-Benz specialists in Birmingham. What are your opinions on a software update? Thank you for the information on ATF servicing. I was under the assumption that it required to be completed every 60,000 miles. Thank you for your assistance, everyone. Quote Link to comment Share on other sites More sharing options...
rab60bit88 Posted February 10 Share Posted February 10 I am uncertain about the A-Class; but, for the C-Class, the 7G+ gearbox requires servicing every 77,500 miles or every 5 years, whichever occurs first. Quote Link to comment Share on other sites More sharing options...
Ken_Lion Posted February 10 Share Posted February 10 The 724 gearbox is a dual-clutch gearbox, not a torque converter type, and therefore requires servicing every 62,000 miles or every 5 years. It is quite probable that a shifting calibration is required, or alternatively, your clutch plates may be worn. It is anticipated that conditions will enhance with a dynamic modification and a software update. Quote Link to comment Share on other sites More sharing options...
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