12 21 520 Removing and installing/replacing preheating control unit (M57T2)

WARNING: This page is about a different car, the 2013 BMW X5, 2012 BMW X5, and 2011 BMW X5. However, it is still accessible from the selected car via links, so may be relevant.

Necessary preliminary tasks:

Read out fault memory of the DDE control unit, work through test plans if necessary.
Switch off ignition.
Disconnect BATTERY NEGATIVE LEAD .
Remove acoustic cover. See 13..... REMOVE THE ACOUSTIC COVERS (M57T2 WITH AND WITHOUT SCR) .
35dX only :
Remove intake port. See 13 REMOVING INTAKE DUCT (M57T2) .

Release positive battery cable (3) from bracket.

Detach fuel delivery line (1) from bracket.

Detach fuel return line (4) from bracket.

Release screw (2).

Tightening torque: 11 13 4AZ .

Fig 1: Identifying Fuel Return And Delivery Line From Bracket

Courtesy of BMW OF NORTH AMERICA, INC.

Unlock plug connection (1) and pull off.

Unlock plug connector (3) and pull off.

Unscrew nuts (2).

Remove preheating relay (4).

NOTE: Shown without coolant hoses for purposes of clarity.

Fig 2: Identifying Plug Connector, Plug Connection, Nuts And Preheating Relay

Courtesy of BMW OF NORTH AMERICA, INC.

Check function of DDE.