How to Solve a Jerky Transmission in a Mercedes A-Class
German cars are known for their performance, luxury, and reliability in the automotive world. That is somewhat of a well-known fact, but one thing that is even better known in the car world is that Mercedes arguably takes the cake in all those departments.
However, reliability is their forte and that shows in all of their vehicles. You can pick up their trucks, sedans, coupes, or hatchbacks, reliability is always world-class.
At least that was what Mr. G had in mind when he bought a 2018 A-Class for personal use. He thought that a fairly new Mercedes vehicle would last him a lifetime, but that was not to be as his A-Class developed a transmission issue a few days after purchase.
Imagine a five-year-old car from a brand known for its reliability developing a major issue. It almost sounds too good to be true. But a once in a blue moon episode like this can happen to anybody. Mr. G’s luck simply ran out the day he purchased the Mercedes A-Class, and he was left with no option but to search for a reputable mechanic to repair his car.
Fortunately, Mr. G chose the Garden City Garage, a specialist Mercedes garage, as the first stop on his way to find a solution for his car’s problem.
Our top Mercedes technician Joshua Williams got the chance to once again show his skills and solve a difficult issue for our client.
The Diagnostic Process
Joshua listened to Mr. G’s complaints about the car and asked relevant questions to find out more about the issue. The questioning process he used is part of the 15-step diagnostic procedure that the mechanics at the Garden City Garage employ at the start of all repairs.
The client came from Llanelli to show his Mercedes to us, so it was worth listening to his complaints. Moreover, the issue Mr. G moaned about turned out to be a big one. He said that the Mercedes gearbox was jerky and took too long to change gears.
That’s something worth testing, so Joshua took the car on a test run to certify the owner’s claims. Sure enough, there was a delay and jerk when the vehicle changed gears. The Mercedes transmission fault was confirmed, but what could be causing it?
There could be several issues that point toward a Mercedes transmission fault, but Joshua had to be sure. He used a diagnostic tool to search the vehicle for fault codes and two relevant ones popped up.
- 056200 – It refers to a power supply circuit 87 undervoltage failure. The code is registered in the Engine Control Unit (ECU) but it should also be noted that most transmissions are controlled through the ECU and not through a TCU (Transmission Control Unit)
- 051300 – This code activates when there is a battery voltage problem or when the transmission is not working properly.
The fault codes show a clearer picture for the technician so he can steer his repair in the right direction. Joshua learned a lot with the two error codes, and he understood that the gearbox was in fact going awry. But what exactly was the problem? Our technician wasn’t sure initially but he didn’t give up and kept working on the car to find out the solution.
The next step for Joshua was to check the software version of the transmission. Sometimes, older software can cause problems, and a simple update can solve them. But that wasn’t the case with Mr. G’s Mercedes A-Class.
The vehicle’s wiring was also perfectly fine and the transmission was getting the right input from all the sources. Even the TCM registered the right input. Joshua load-tested the power and ground wires, and they all worked fine.
So, why then was the ECM registering the fault codes, and the transmission was jerky?
Well, after much deliberation and research, our technician found out that the mechatronics unit inside the transmission was at fault. The said component is responsible for shifting the gears, and it was either damaged or faulty by the manufacturer. In any case, the only way out for Mr. G was to opt for the repair, and that is what he did.
The Solution
The 15-step diagnostic procedure that Joshua, our expert Mercedes specialist used, helped him reach the core of the problem, and he determined that a mechanical part was at fault.
Now, there are two ways one can adopt repairs like these:
i) Repair the old part
ii) Replace the old and install a new like-to-like component
Both require money, but it is better to go for a brand-new part, especially if the car is five years old.
Our technician discussed all the options with the vehicle’s owner, and they decided that it was better to install the new part.
So, after gaining permission from the car’s owner, Joshua opened up the transmission and put in a new mechatronics unit inside. The disassembling process is quite hectic, and it takes a lot of time, but our technician managed to do all of that in a short amount of time.
The repair job was so quick that Mr. G was able to drive back home in his A-Class.
But before he could leave, Joshua had one more job to do, and that was to initiate the teach-in process. He used the Xentry Kit 4 to encode and program the new unit. That’s what happens when a new part goes in, the ECU has to be trained to accommodate the new component. This procedure takes a bit of time, but for a professional like Joshua, it takes an hour or a half.
Summary
Mr. G came into the Garden City Garage with his Mercedes A-Class, complaining about a jerky transmission. His issue seemed mechanical from the start, but our technicians use a 15-step diagnostic procedure that forces them to check every possibility. Joshua, our technician, did the same as he ticked down the list of possible reasons for the issue.
Once all the tests were conducted, the real issue presented itself, and Joshua caught it red-handed. He fixed the problem by replacing the part and sent Mr. G back home once the work was done.
By opting for the Garden City Garage, Mr. G saved his precious time and valuable money. He was kept well informed throughout the repair procedure, and as a result, Mr. G left as a satisfied customer.
At the Garden City Garage we take pride in providing the best customer service to our clients. Not only that but you get cooperative and friendly staff that discuss your car’s problems with you before employing any kind of solution.
If you have been looking for service like this, perhaps it’s time to put your trust in Garden City Garage. You can reach us at 01639 320032 to book an appointment.
