BMW 7 Series: Notes/Information On Removing And Installing Control Units
IMPORTANT:
- Disconnecting the vehicle battery will cancel the fault memories of
control
units. Consequently, before disconnecting the car's battery, always
interrogate the fault memories. Investigate stored faults and, once any
faults have been remedied, cancel the fault memory.
- Control unit plugs should only ever be connected and disconnected
while
the ignition is turned off.
- The removal and installation of components, relays, fuses etc. can
cause
faults to be stored in fault memories capable of self diagnosis. Always
interrogate the fault memories after completing work on the electrical
system.
- Investigate stored faults and, once any faults have been remedied,
cancel
the fault memory.
- If necessary, initialize power window units
When replacing the DME/DDE control unit, observe the following:
- In each case read out the hardware/software status of the relevant
control
unit using the BMW diagnosis system.
Comply with the instructions of the DIS diagnosis system on the steps
pertaining to coding and programming.
On vehicles with electronic vehicle immobilization, comply with the
instructions of the BMW diagnosis system.
- Each control unit is programmed with certain basic values, which
serve
as mean values. The control unit receives different input values,
depending on engine condition, which are compared with the stored
values. The adaptive system compares the input values with the stored
map values. The control commands are routed to the relevant actuators.
- If the DME control unit is without current for a long time (more than
one
hour), its adaptive system loses the stored values. When a cleared control
unit is restarted or a new control unit is installed, the adaptive system
must read in and store the input values of the associated engine as new
basic values itself.
- This procedure could lead to erratic idling and disturbed overrunning
of
the engine after starting. Depending on the engine it could require some
time before all values are adapted to the engine condition.
- Therefore observe the following procedure before replacing or
reinstalling
a DME/DDE control unit:
1. If possible before exchanging control unit, run engine up to operating
temperature.
2. Exchange control units and run the vehicle at alternating engine speeds.
NOTES/INFORMATION ON START ASSISTANCE (JUMP STARTING)
Do not start the engine with help of starting sprays.
Preparation
Conform with the following when starting the engine with a jump starting
cable.
- Ensure that the jump starting cable wires are of appropriate
cross-section size.
- Only use fuse-protected jump starting cables.
- Check whether the current-supplying battery has 12 V voltage.
- If the engine is started from the battery of another vehicle, ensure
that there is no contact between the
bodies of both vehicles.
IMPORTANT: Never touch electrically live ignition system components: high
voltage -
danger of injury!
If the battery in the vehicle supplying power is weak, start the engine of
this vehicle and let it run at idling
speed.
Operation
It is essential to conform to the procedures so as to avoid injury to persons
or damage to parts.
- Automatic transmission: select drive position "P", apply parking brake.
- Manual transmission: move gear lever to neutral position, apply parking
brake.
- Ensure that the jump leads cannot get caught in rotating parts, e.g.
fan.
- First connect both positive poles of the batteries with one jump
starting cable (red).
- Use the battery positive terminal in the engine compartment for vehicles
with the battery in the luggage
compartment.
- Then use the second jump starting cable (black) to connect the negative
post of the current-supplying
battery with the earth/ground point (not the negative pole or the body) of
the vehicle to be started.
IMPORTANT: Do not connect the second jump starting cable (black) with the
negative pole of the battery in the vehicle to be started. Produced gas could be
ignited by sparks.
Risk of explosion!
After the engine of the vehicle to be started has fired, first disconnect the
jump starting cable between the
negative pole and the earth/ground point. Then remove the starting cable from
the positive poles.
READ NEXT:
WARNING: If the engine hood/bonnet contact is pulled upwards (workshop
mode), the information "switch closed" is output. The automatic engine
start-stop function is active.
An automatic engine star
REPLACING ALL SPARK PLUGS (N54, N63, N74)
Necessary preliminary tasks
Switch off ignition.
Remove IGNITION COILS.
IMPORTANT: Wear safety goggles.
Oil and dirt particles may get into your eyes!
Cl
NOTES ON CHECKING IGNITION SYSTEM
Troubleshooting
Fault in fuel injection system
Spark plug faults
Ignition coil faults
Further fault patterns with evaluation
Additional fault notes for troubles
SEE MORE:
Procedure OBSERVE repair stage 3! Read contents of BODY, GENERAL.
Spot-weld bonding is used on this vehicle. Observe specific procedure.
Place vehicle on straightening bench.
Following new body parts are required:
A-pillar, outer
Connection, side frame
Shaped part, carrier support, wheel arch
Notes
Set pressure regulator on special tool 16 1 171 fully in "-" direction.
Connect special tool 16 1 171 using compressed air line (1) to workshop
compressed air system (8... 10 bar).
Connect pressure sensor (2) from Diagnosis and Information System.
Connect special tool 16 1 172 to quick-rele