Mercedes “Do Not Change Gears” Warning – What’s Wrong?

The transmission or gearbox system of your Mercedes Benz is likely to have a fault that will trigger the vehicle's computer to display an error/warning message on the dashboard screen. Error codes that are related to the fault(s) could be logged in as well. And you'll be able to use a compatible diagnostic scanner to read them.

Do not change gears message highlights

• Common reasons:problems with the transmission
• How to fix:just take the car in ASAP
• Possible consequences:transmission may die quickly
• Priority level:High
• Can you drive?Not recommended
• DIY repair:Impossible
• Repair price range:$250-$4,000

We've described how to deal with this trans problem so that you can get the vehicle on the road again with no difficulty in going into gear or shifting. You'll also know how to relate with the auto repair shop in this scenario to ensure that the best service is rendered.

Seeing the Mercedes Benz "Do Not Change Gears" Message on Your Dashboard Screen

The message you're seeing on the dash display of your Mercedes could also tell you to drive to the workshop, apart from alerting you not to switch gears. These are two Instructions that shouldn't be taken lightly.

Heed the dashboard warning as stated in the introduction. But try to park the car at a convenient place quickly, if you aren't comfortable with driving further. For example, on the side of the road. Another factor to consider is the proximity of the nearest repair shop.

Parking and LEAVING THE CAR ON is the only way to play safe when you can't get the vehicle to an auto repair shop. Drive without stopping if you can, but aim to go up the ramp in the mechanic's workshop and stop there without turning the car off.

This means you'll have to contact the auto repair shop that you're on your way. Describe your issue and tell them that you'll be going to be going up the ramp.

1) Why You Shouldn't Stop or Switch off the Car

Stopping the car and switching it off will make it difficult to tow the vehicle or push it to the side of the road from the middle. And it will be bad if you put it off in the middle of the road and not on the side. Towing will be hard when trying to jack up and unbolt the prop shaft to enable the car to be conveyed to a dealership.

It may be the first time you're experiencing such conditions, so ensure that you stay calm as you get through the situation. Keep in mind that many other Mercedes users have experienced this issue over the years.

2) Other Mercedes Users With the Same Issue

Even customers who bought their Mercedes vehicles brand new have had to return them to their dealers for trans system checks only after a few days. And this is because of the warning message.

You'll see some online forum contributors who claimed they had to return the cars for a refund because the issue made them develop cold feet about continuing to use the vehicle. Their money was refunded by the manufacturer, of course. This is regardless of going as many as 150 miles with the car already.

However, if your car is an old model-year Mercedes or its returns policy has expired, then you can't return it to the dealership to get a refund. All they can do is to help you fix the fault.

What Happens When You Try To Change the Gears or Continue Driving?

The car may not even go into gear during this period if you attempt a shift. If it does manage to make the switch, then it's only a matter of time before it stops being able to. For example, if you switch the car off and put it on again or restart the vehicle.

So don't assume that all is well if it hasn't stopped shifting. Expect the shifting to stop and the following to happen while seeing the "Do Not Change Gears" notice on the display:

• Beeping when switching on the engine after putting it off.
• Inability for the car to move after stopping it.
• The engine may go off on its own.
• The car may not be able to go into "park" for several minutes. You should see a dashboard message indicating this.

You may have to call a tow service to convey the car to a mechanic's workshop in the event of any of the above. Some drivers use a restart trick to put the vehicle into "drive" (D) so that they'll be able to move it further if it goes off on its own. They use this method to avoid being stranded or having to pay for a towing service.

The trick involves putting the ignition to "off" and restarting the engine. This may get you to a nearby auto repair shop, but it's not worth the risk. Although the circumstances may require you to try this trick as a logical solution to getting stranded, not being able to get help through your phone, or being in an unsafe condition.

Still, you'd have to find another way to get out of that situation, if the vehicle refuses to engage "drive" even after restarting the engine several times. And you wouldn't want to take the risk of driving after stopping the car because the fault could deteriorate or put you in a worse situation.

When You Just Replaced the Transmission

In the case of a newly replaced transmission, the auto repair shop that did the change would most likely fix the dashboard warning issue related to gear shifting free of charge. They're supposed to, especially if they used a bad trans or the new one developed a defect.

You could also demand the above-mentioned benefit if the issue could have easily been avoided during the swap. It's only right that a mechanic who's at fault should be the one to tow the vehicle from your location to the repair shop.

So call the auto repair shop or dealership to demand free towing when you see the warning message just after a short mileage with the new trans. It could even be as high as 150 miles.

How a Professional Mercedes Benz Mechanic Will Resolve the Issue

The auto repairer will hook up a sophisticated Mercedes Benz-compatible scan tool or computer to the car to see if there are error codes available. The primary goal will be to look for codes that are related to the transmission system. So many trans-related codes may pop up in this case.

Mechanics also perform tests and physical checks to ascertain if it's an electronic or mechanical issue. And certain issues could come up which may not be from the trans system.

1) Possible Faults To Be Fixed

There may be a need for a software update to reprogram the TCM (transmission control module) so that it can function properly. The intelligent shift module (ISM) is a common culprit as well. You'll have to replace it and clear the error codes for the warning message to stop showing and the car to come back to normal.

Other potential faults that trigger the dash screen alert are listed below.

• Bad speed or accelerator pedal sensor
• Faulty control harness socket/pin
• Low battery voltage
• Defective lockup torque converter clutch
• Bad trans fluid

You may notice some related symptoms to the low battery voltage problem such as the eco start/stop function not working, the horn sounding weaker, the auto trunk opening function not responding, etc. The fix for this will be to recharge the battery, repair its faults, or replace it.

2) Repair Costs To Expect

You may have to pay for a trans fluid replacement if it hasn't been done in the last 60,000 miles. We can tell you that the need for a trans rebuild as a fix is very unlikely.

Expect to pay over $500 for the replacement of some parts and a fluid change. This is in consideration of multiple hours of labor-maybe three. But the added replacement of something as significant as an electronic selector module could make that total hit over $2,000.

It's hard to give an estimate for the total repair work that may be done on your Mercedes. This is because of the varying combinations of error codes that may come up on the diagnostic scan results for this kind of issue.

Conclusion

You could be fortunate to have a warranty that covers the costs of repair and/or towing. But that's if the vehicle or transmission was bought brand new. It will be a good thing to have a personal diagnostic scan tool in this situation to at least read the error codes. This is true especially when you can't drive the car to the mechanic's place.