Mercedes 7G-Tronic - Seven Speed Automatic Gearbox Problem
This is a very common fault for Mercedes vehicles fitted with the 7G-Tronic automatic transmission with gearbox code - 722.9, often causing the transmission to hold too long in one gear before aggressively forcing the next gear into place, this causes a very rough and jerky gear change.
The fault usually starts out as intermittent but always becomes permanent if left unresolved for long enough. The fault is caused by the TCM conductor plate breaking down internally, preventing the control module/conductor plate from monitoring the correct rotational speed of the input shaft, making it unable to determine the slippage of the torque converter, causing ineffective torque clutch lock-up that prevents a smooth gear change or in some cases prevents gear selection entirely.
We can now fully rebuild your own control unit within 2-3 working days and supply an unlimited mileage lifetime warranty*
Diagnosis:
When attempting to diagnose the transmission fault it is best practice to have the fault codes read from the transmission system as a first point of call, if you have fault codes stored for the internal speed sensors then this is a very good indication that you have a faulty transmission control module/conductor plate.
Common Failure symptoms:
- Intermittently not changing gear
- Gearbox goes into limp mode
- Sticking in gear
- Not selecting gears
Common fault codes:
- 0717 – The Signal From Component Y3/8N1 (Turbine Speed Sensor, VGS) Is Not Available.
- 0718 – The Component Y3/8N1 (Turbine Speed Sensor, VGS) Is Defective.
- 2201 – The Component Y3/8N2 (Internal Speed Sensor) Is Defective.
- 0722 – Output Speed Sensor Y3/8N3 Output Speed Sensor VGS Not Available
- 0721 – The Transmission Output Speed Signal Is Implausible When Compared To The Wheel RPM Signal
Common failing part numbers:
- A0335457332
- A0034460310
- A0335456732
- A0009013000
- A0009013200
- A0009017100
Removal instructions:
- Drain gearbox oil
- Remove oil pan & internal oil filter
- Unscrew the 10 screws holding the valve body to the gearbox
- Unplug the control module multi-plug connector and then remove valve body from the gearbox - do not use a pry-bar/screwdriver to force the multi-plug connector from the gearbox housing when removing the valve body or it may break the connector.
- Remove the 10 screws that hold the control module to the valve body
- Remove the 8 solenoids that connect through the control module to the valve body (make note of their positions for correct re-installation)
Test and rebuild:
We can now fully rebuild your own 7G-Tronic control module and supply an unlimited mileage lifetime warranty for a fraction of the cost of a new unit. When we rebuild your own control module we use higher rated components than standard, so you can be assured that once rebuilt, your control module will not fail again – this is how we are able to supply a lifetime warranty with every unit we rebuild.
Programming:
These control modules are programmed to the vehicle’s immobiliser and chassis number, so it is not possible to fit a second-hand unit to the vehicle, the only option other than purchasing a brand new unit from the manufacturer is to have your own control module rebuilt. When we rebuild your control module we retain all the original programming so that you can just fit the unit back to the vehicle without any additional programming - simple plug and play.
Quality:
We rebuild these 7G-Tronic control modules for Mercedes main dealers and specialists all over the globe, so you can be assured of our very high standard of work. We use higher rated than standard components when we rebuild your control module so you can be assured that once your unit is rebuilt then it will not fail again, therefore we give an unlimited mileage lifetime warranty with every control unit we rebuild.
Warranty:
Lifetime unlimited mileage*
How do I get my unit rebuilt?
To pay for the rebuild select your model above and then click: Get yours rebuilt
Print the payment/booking confirmation email.
Package the Mercedes 7G-Tronic transmission ECU inside a sturdy box with plenty of packaging material (make sure you include your confirmation email in the box).
Send us your package by tracked courier (the shipping instructions are on the confirmation email).
Once received we will test, rebuild and return your 7G-Tronic control module with an unlimited mileage lifetime warranty. (if your unit turns out not to be faulty then we will refund your payment less a small testing fee and return shipping)
What if I don’t want to pay up front?
This is not a problem, if you prefer this option then follow the following steps:
Fill in and submit this test form.
Print the booking confirmation email.
Package the Mercedes 7G-Tronic transmission ECU inside a sturdy box with plenty of packaging material (make sure you include your confirmation email in the box).
Send us your package by tracked courier (the shipping instructions are on the confirmation email).
Once received, we will test your transmission control module and call you to advise on the outcome of testing, if your unit is faulty and you choose to go ahead with the rebuild then we will take payment over the phone using a debit/credit card.
We will then rebuild your 7G-Tronic ECU and return it to you with an unlimited mileage warranty.
If you require further information regarding this Mercedes 7G-Tronic transmission ECU, then please contact us.