LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> BMW >> 2011 >> 335d >> Repair and Diagnosis >> Engine Performance >> Ignition System >> Engine Electrical System - Repair >> 1290 control unit box >> 12 90... Removing and installing/replacing electronics box
April 5, 2026: LEMON Manuals is launched! Read the announcement.

12 90... Removing and installing/replacing electronics box

IMPORTANT: Read and comply with notes on PROTECTION AGAINST ELECTROSTATIC DISCHARGE (ESD PROTECTION) .
NOTE: Follow instructions for REMOVING AND INSTALLING ELECTRONIC CONTROL UNITS 

Necessary preliminary tasks 

Release screws (1).

Slacken nut (2).

Lift out right heater end plate (3).

Installation: 

Ensure gasket (4) is correctly seated.

Fig 1: Lifting Out Right Heater End Plate
G04751296Courtesy of BMW OF NORTH AMERICA, INC.

Unlock fasteners (1) from below and slide upwards approx. 10 mm.

Unlock locks (2) in direction of arrow.

Remove cover (3).

Fig 2: Unlocking Locks
G04751288Courtesy of BMW OF NORTH AMERICA, INC.

Disconnect plug connection (1).

Unlock plug connection (2) in direction of arrow and disconnect.

Pull wiring harness grommet (5) out of electronics box and remove wiring harness (4).

Pull wiring harness grommet (3) out of electronics box and remove wiring harness with equipment carrier (6).

Installation: 

Make sure wiring harness grommets (3, 5) are correctly seated in electronics box.

Fig 3: Identifying Electronics Box With Plug Connection, Fuse Carrier And Wiring Harness Grommet
G04751309Courtesy of BMW OF NORTH AMERICA, INC.

If necessary, press locking tabs (1) in direction of arrow and pull contact carrier (2) out of housing.

Fig 4: Pressing Locking Tabs
G04751300Courtesy of BMW OF NORTH AMERICA, INC.

If necessary, press locking tab (1) in direction of arrow and pull contact carrier (2) out of housing.

Fig 5: Pressing Locking Tab
G04748631Courtesy of BMW OF NORTH AMERICA, INC.

Release screws (1).

Replacement 

Modify water drain valve (2) and bump stop (3).

Fig 6: Identifying Water Drain Valve, Screws And Bump Stop
G04751305Courtesy of BMW OF NORTH AMERICA, INC.

Installation: 

Make sure gasket (1) is correctly seated on electronics box.

Fig 7: Identifying Electronics Box Gasket
G04740388Courtesy of BMW OF NORTH AMERICA, INC.


IMPORTANT: Read and comply with notes on PROTECTION AGAINST ELECTROSTATIC DAMAGE (ESD PROTECTION) .
NOTE: Follow instructions for REMOVING AND INSTALLING ELECTRONIC CONTROL UNITS 

Necessary preliminary tasks 

Release screws (1).

Slacken nut (2).

Lift out right heater end plate (3).

Installation: 

Ensure gasket (4) is correctly seated.

Fig 1: Lifting Out Right Heater End Plate
G04751296Courtesy of BMW OF NORTH AMERICA, INC.

Unlock fasteners (1) from below and slide upwards approx. 10 mm.

Unlock locks (2) in direction of arrow.

Remove cover (3).

Fig 2: Unlocking Locks
G04751288Courtesy of BMW OF NORTH AMERICA, INC.

Lift out plug connection (2), fuse carrier (3) and wiring harness grommet (4) from electronics box (1).

Installation: 

Make sure wiring harness grommets (4) are correctly seated in electronics box (1).

Fig 3: Identifying Electronics Box With Plug Connection, Fuse Carrier And Wiring Harness Grommet
G04751298Courtesy of BMW OF NORTH AMERICA, INC.

Unlock DME control unit at holders (1) and raise slightly.

Pull tab (3) in direction of arrow out of housing and disconnect plug connections (2) on DME control unit.

Fig 4: Pulling Tab Out From Housing
G04751299Courtesy of BMW OF NORTH AMERICA, INC.

If necessary, press locking tabs (1) in direction of arrow and pull contact carrier (2) out of housing.

Fig 5: Pressing Locking Tabs
G04751300Courtesy of BMW OF NORTH AMERICA, INC.

If necessary, press locking tab (1) in direction of arrow and pull contact carrier (2) out of housing.

Fig 6: Pressing Locking Tab
G04748631Courtesy of BMW OF NORTH AMERICA, INC.

Unlock device holder (2) at holder (1) and remove.

Remove DME control unit (3).

Fig 7: Identifying DME Control Unit With Holders
G04751302Courtesy of BMW OF NORTH AMERICA, INC.

Unlock device holder (2) at holder (1) and remove.

Fig 8: Identifying DME Control Unit Holders
G04751303Courtesy of BMW OF NORTH AMERICA, INC.

Remove device holder (1) from electronics box.

Fig 9: Identifying Holder
G04751304Courtesy of BMW OF NORTH AMERICA, INC.

Release screws (1).

Replacement 

Modify water drain valve (2) and bump stop (3).

Fig 10: Identifying Water Drain Valve, Screws And Bump Stop
G04751305Courtesy of BMW OF NORTH AMERICA, INC.

Installation: 

Make sure gasket (1) is correctly seated on electronics box.

Fig 11: Identifying Electronics Box Gasket
G04740388Courtesy of BMW OF NORTH AMERICA, INC.