How to put a Mercedes Benz in neutral without a key?
This blog will answer the following questions: How to put Mercedes Benz in neutral without a key? What are the common faults in Mercedes Benz transmissions? What to do if Mercedes Benz does not come out of Park? Which Mercedes Benz models cannot be put in Neutral without a key?
How to put a Mercedes Benz in neutral without a key?
To put Mercedes Benz in neutral without a key follow the procedure given below:
- Remove the boot on the gear selector lever using a plastic wedge.
- Locate the gear selector lever release switch and press it using a pen or a screwdriver.
- Keep the release switch pressed and pull the gear selector lever in the neutral position.
- Take out the pen or screwdriver and install the rubber boot back in its original position.
Do not use a sharp object to remove the boot on the gear selector lever as it can damage the fabric. Alternatively, the trim under the gear selector lever can also be removed to press the release switch by hand.
This method is only applicable to Mercedes Benz cars with a gear selector lever in the center console. All the 5G-Tronic automatic transmissions have a gear selector lever connected to a detent lever on the transmission housing.
Mercedes Benz started using an intelligent servo module on the 7G Tronic plus transmission. The electronic selector lever was also integrated into the steering column module. Hence, this method does not apply to the models with shift levers in the steering column module.
The vehicle must be unlocked to gain access to the gear shift lever. If the key is unavailable and the vehicle is locked then access to the car must be gained by ordering a replacement key from the authorized dealership.
If a vehicle hoist or jack is available, it is possible to shift the transmission to the neutral position by disconnecting the shift rod from the detent lever and moving it by hand. The methods discussed above can work even if the battery is completely dead as the transmission is shifted into neutral manually.
Mercedes Benz cars with manual transmissions do not have parking gear. An electronic steering lock is present in the steering column that prevents the wheel from turning.
What are the common faults in Mercedes Benz transmissions?
The common faults in Mercedes Benz transmission are explained below:
- Without changing gear consult to workshop
When there is a fault code present in the fault memory of the transmission control unit, a warning message appears in the instrument cluster. The fault is related to missing communication with the electronic selector lever or the transmission control unit.
When this fault occurs, it is no longer possible to change gears and select N or D by actuating the selector lever or gear stick. The gear stick can be moved by using the release switch but the vehicle will not start as the engine control unit cannot read the position of the transmission selector lever.
The fault in communication can be due to the power supply or the interruption in the CAN voltage signal. Without the CAN signal, the electronic gear selector cannot send the current gear position signal to the transmission and the engine control unit.
- Internal control unit fault
The transmission control unit is at the heart of performing the gear changers so if a fault code is related to an internal malfunction, the neutral gear cannot be selected. Mercedes Benz is using a fully integrated transmission control unit in the valve body.
The transmission control unit is also personalized to each vehicle. Therefore, the transmission control unit must be replaced if there is an internal fault and a newer software update is unavailable.
- ISM inoperative
The ISM or intelligent servo module is present on the 7G-Tronic transmission. The shift lever in the steering column module sends the gear position signal selected by the driver. The servo motor in the ISM then operates the detent lever on the transmission.
When there is a fault in the ISM, the servo motor becomes inoperative and it cannot move the detent lever on the transmission. The servo motor can be actuated from the OBD-II scan tool but the vehicle key must be preset and the ignition ON is required for drive authorization.
What to do if Mercedes Benz does not come out of Park?
If Mercedes Benz does not come out of the park, perform the following steps:
- Turn the ignition ON/OFF two times.
- Check if there is any warning message on the instrument cluster.
- If a warning message appears in the instrument cluster, the gear shift indicator will not show the correct gear.
- Select the neutral gear if the Mercedes Benz has a gearshift lever.
- If the Mercedes Benz has an electronic selector lever, a freewheel adaptor must be installed on any one of the drive wheels.
The transmission does not come out of Park when there is a fault in the gearbox. The vehicle must be towed on a flatbed lift. A jack can be used to bring the vehicle into the position for towing. However, if the vehicle is flat-towed or with two wheels on the ground, damage can occur on the drive wheels.
Which Mercedes Benz models cannot be put in Neutral without a key?
The Mercedes Benz models with the 7G Tronic plus and the latest 9 G Tronic transmissions cannot be put into neutral without a key. In the 7 G Tronic plus transmission, gear shifting is performed with the help of ISM. ISM is programmed and assigned to the vehicle permanently.
The 9 G Tronic transmission also has a fully integrated control unit and uses an electrohydraulic valve body to perform gearshifts. Both the ISM and 9G Tronic transmission are part of the drive authorization system.
The drive authorization cannot be completed without the key. Therefore, the transmission can never be put into neutral. Even if the main battery is disconnected, there is an additional battery to actuate the park pawl gear and the vehicle will automatically go into P gear.
When the ISM fails or the transmission control unit has a communication fault, the vehicle cannot be moved as a mechanical park pawl gear locks the output shaft of the transmission. As a last resort, the propeller shaft has to be disconnected from the transmission, to take the vehicle out of Park gear.
This blog explained the procedure to select neutral in Mercedes Benz without a key. When there are no faults in the transmission and the key is present, the neutral can be selected by pressing the selector lever halfway down. All the latest Mercedes Benz models require a key for selecting neutral.