When you want to replace new ECU,program bmw keys,BWM ECU programming..etc,you need to remove BMW ECU from BMW vehicle.So this instruction show you a step-by-step guide on how to remove BMW F30 N55 ECU/DME by yourself from vehicle body.This instruction original from F30 forum member @Jadar,big thank for his excellent work!!!
And try this at your own risk!!!
What You Need?
11mm socket and ratchet
BMW F30 N55 ECU DME Removal Procedures:
Disconnect the battery using a 10mm socket
Remove engine cover by pulling up on it and disconnect the grommets
Unplug the mass air sensor located on the intake
Unplug the vacuum line on the intake by pinching the 2 ribbed portions
Pinch,it will take some effort do not crack or break retainers
Unplug this vaccum sensor next by pushing up on the metal clip retainer.Its some type of vacuum sensor.
Pry off rubber mount with your hand not much effort needed.
Take off the rain cap by using a 10mm socket counter clockwise unlocks it,then just pull upp.
Remove the rubber weatherstrip going across engine bay.
Also take out the cable stowed in the rubber.
Take off the foam engine cover/noise by gently pulling up and toward front of the car.
Disconnect the T Map
Remove the 2 T25 torx screws
On passanger side of the car disconnect the fuel rail sensor by pushing on the metal retainer.
Take out the locator,you will need all the space you can get.
Disconnect the O2 sensors located on the passanger side of the car.They are keyed don’t worry about criss crossing them,it is not possible upon reassembly.
Lead them and stow them on the driver side for now.
You will need to disconnect the other end of the PCV hose on the passanger side.Same here squeeze the ribbed parts it.It take some effort.They are tricky.
Swing that vacunm hose over,and you can either pull it out from the bottom or leave it for now.I left it due to not knowing how it was attached under the manifold,but its just a sleeve fitting that you will see shortly.
The DME connectors.
There are a total of 6.
To remove start on the 3rd one.You can not see the last 3 yet.They have a cam lock lever.I will show you the order of removal.
To release cam lock push lock with index finger,then with your thumb tull towards the firewall.It will open and you can pull up on the connection.
Cam lock swung open.Take your time do not brake stuff it will just cause you more downtime and money.
1st 3 are removed and now you can see the last 2 connections.They also have an order of removal and #4 is very tricky,i struggled a bit,but i do have another way if you can not get it.
There are bolt style 11mm fastners on the ends unscrew these and set in a safe place
There are a total of 7 fastners on the manifold they are all 11mm.
Unplug the sensor as well marked as below:
2nd bolt style fastner under the cowl
The last 11mm is hidden under the cowl
The remaining 5 are 11mm nuts,yes i have magnet apex sockets and it makes life easier
Undo the rest of the nuts.
The manifold should be loose but do not get crazy and start pulling on things.The charge pipe has to be removed.
If you get stick with the DME connectors 4,5 and 6,you can undo the DME from the backside using an E8 socket.Now this comes with some caution.Tape off your intake runners and charge pipe.The last thing you want to do is drop an E8 screw into your intake runner and ruin your life.
This is the under side of the mainfold,now there are 2 connectors you must remove
There are four E8 screws there are also two 8mm bolts on the other side of the manifold you must remove.
Regardless of the order you took our your manifold and DME I highly reccomend taping off the runners and charge pipe to prevent a catastrophie.
Remember that vaccum hose i said to stow or pull up on,well this is it snaking through the mainfold,just pull up on it as lits just a sleeve and easily comes off.Like I said i did not pull up on it as i could not tell how it was hooked up and the last thing you ever want to do is just pry and pull up on connectors and brake them.
Back to the DME connections 4,5 and 6.
5 and 6 do not have a particular order,its whatever you want,but 4 must be before those.This was very tricky for me hence i resolved to unbolting the manifold while DME remained attached.But seeing it like this will help you guys understand better.
Its a bar style cam lock.It will take some effort you may need something to pull down on it.But pull straight down and it will unlock.
After unplugging 4 disconnect 5 and 6 and the manifold will lift your,just be careful there are some wires tucked in the manifold or if you did it by unbolting the DME 1st the manifold is out and the DME is ready for removal.
Ignore my JB4 wiring
If you managed to undo all the connectors with the DME attached to the manifold,you now have to seperate the tow.There are two 8mm fastners on top.
Under the manifold remove the four E8 screws.
And after then if you want to open ECU/DME,please refer here:
How to Open Remove BMW N20 Engine ECU Cover