
Downloaded from www.Manualslib.com manuals search engine
Fuel Tank and Fuel Pump
4 Relieve system pressure and attach a fuel pressure gauge as
described in Fuel pressure gauge, installing (6-cylinder
models) or Fuel pressure gauge, installing
(V-8 models).
WARNING-
Fuel in fuel line is under pressure (approx. 3 - 5 bar or 45 -
75psi) and may be expelled underpressure. Do not smoke
or
worlc near heaters or other fire hazards. Keep a fire ex-
tinguisher handy Before disconnecting fuel hoses, wrap a
cloth around fuel hoses to absorb any
leaking fuel. Catch
and dispose of escaped fuel. Plug all open fuel lines.
Always unscrew the fuel tank cap to release pressure
in the tank before
working on the tank or lines.
- Operate fuel pump as described in Operating fuel pump for
tests. Compare fuel pressure to specifications in accompa-
nying table.
Fuel pressure specification
All E39 vehicles 3.5 +0.2 bar (50.76 i2.9 psi)
- If pressure is low, repeat test while gradually pinching off re-
turn hose to fuel tank. Pressure should rise rapidly. If not, fuel
pump is most likely faulty. If pressure rises, the fuel pressure
regulator is most
likely faulty.
- If pressure is too high, checlc return line from pressure regu-
lator to tank. Check for
ltinks in hose. If no faults can be
found, pressure regulator is most likely faulty.
CAUTION-
The fuel pump is capable of developing a higher pressure
than that regulated by the pressure regulator. In the event the
fuel pump checlc valve is faulty (stuck closed), male sure the
I fuel pressure does not rise above 6.0 bar (87psi). Damage
to the fuel lines or fuel system components could result.
- Reassemble engine, noting the following:
Remove fuel pressure gauge and fittings.
Replace schraeder valve, if removed
Replace fuel pump relay.
Replace fuel filler cap.
Residual pressure, testing
For quick restarts and to avoid vapor lock when the engine is
hot, the fuel injection system retains fuel pressure after the
engine is shut off. This residual pressure is primarily
rnain-
tained by the fuel pressure regulator and a checlc valve at the
fuel pump
outlet.

Downloaded from www.Manualslib.com manuals search engine
170-5
Radiator and Cooling System
Fan switch calibration (M52, M62 engine)
coniprairoi OUt rlgnal
Auto. ciimilte ~ontioi inpuls via CAN bus
Electric fan activation:
Low speed
91°C (196°F)
High speed 104' C (21 9' F)
< In models manufactured after 911998 (M52 TU engine, M54
engine.
M62 TU engine), the electric cooling fan is controlled
by the engine control module (ECM) via the output final
stage.
The output final stage is mounted on the fan housing, next to
the fan motor. The fan is operated using a pulse width modu-
lated signal. Fan circuit wiring is protected by a 50-amp fuse.
Electric fan activation is based on the following inputs to the
ECM:
Radiator outlet temperature
Calculated catalytic converter temperature
Vehicle speed
* Battery voltage
Calculated
A/C pressure
When the vehicle is first started, the ECM activates the elec-
tric fan briefly at 20% of its maximum speed, then switches
off. This is for diagnostic monitoring. The voltage generated
by the fan when it slows down (acting as a generator) must
match the stored rpm values in the fan output stage toconfirm
that the fan is operating correctly.
NOTE-
If the ECM fault memory indicates a cooling fan fault, check
that the fan is not seized and that it spins freely.
When
A/C is switched ON, the electric fan is not immedi-
ately turned on.
After the engine is switched
OFF the fan may continue to
run at varying speeds for up to 10 minutes, based on cal-
culated catalyst temperature.
Transmission fluid heat exchanger
Automatic transmission fluid lines circulate transmission fluid
(ATF) to and from a heat exchanger at the radiator.
All 6-cylinder
models andV-8 models produced to 911998 are
equipped with a transmission cooler located in a cooling cas-
sette in front of the radiator.

Downloaded from www.Manualslib.com manuals search engine
Anach pressure brake bleeder to fluid reservoir and pump
bleeder a few times to pressurize hydraulic fluid system.
CAUTION-
* Do not exceed 2 bar (29 psi) pressure at the fluid resenfoil
when bleeding or flushing the hydraulic system.
Brake fluid is poisonous, highly corrosive and danger-
ous to the environment. Wear safety glasses and
rub-
bergloves when working with brake fluid. Do not siphon
brale fluid with your mouth. Immediately clean away
any fluid spilled on painted surfaces and wash with wa-
ter, as brale fluid will remove paint.
Always use new brake fluid from a fresh, unopened
container.
Brake fluid will absorb moisture from the air.
This can lead to corrosion problems in the clutch and
brake hydraulic systems, ;nd will also lower the brake
fluid boiling point. Dispose of brale fluid properly.
- Raise and safely support vehicle.
WARNING-
Make sure the car is stable and well supported at all times.
Use a professional automotive lift orjackstands designed for
the purpose. A floor
iack is not adequate support.
- If necessary, remove transmission splash shield.
Hydraulic system, bleeding
Worlting underneath transmission, connect a hose from
clutch slave cylinder bleeder valve
(arrow) to a container.
Open bleeder valve and allow bralte fluid to expel until
clean fluid comes out, free of air bubbles.
Close bleeder valve and disconnect pressure bleeding
equipment from fluid reservoir.
Slowly operate clutch pedal about
10 times. Fill reservoir
with clean fluid as necessary.
CR* .,,, .rP,ll,h.:I,,~,~mn.lI","i,,i"

Downloaded from www.Manualslib.com manuals search engine
21 0-6
1 Clutch
Hydraulic system, bleeding
(using
BMW special tool 21 5 030)
4 Working underneath transmission, remove slave cylinder
mounting nuts (arrow) from clutch housing and remove
cylinder. Leave fluid line attached.
4 Use BMW special tool 21 5 030 to press slave cylinder push-
rod completely into slave cylinder.
Hold slave cylinder so that bleeder valve is at highest point.
Open bleeder valve and allow brake fluid to expel until
clean fluid comes out, free of air bubbles.
* Close bleeder valve and disconnect pressure bleeding
equipment from fluid reservoir.
Slowly unscrew and detach special tool 21
5 030 from
slave cylinder.
CAUTION-
Do not remove tool if hydraulic system is pressurized.
- Reinstall slave cylinder.
Tightening torque Slave cylinder to transmission case
22 Nm (1 6 ft-lb)
- Slowly operate clutch pedal about 10 times. Fill reservoir with
clean fluid as necessary.
Clutch master cylinder, replacing
The clutch master cylinder is mounted to the pedal assembly
directly above the clutch pedal.
Working inside engine compartment, remove left interior
ventilation filter housing:
Release 3 plastic taps
(A) on duct. Earlier models use a
single release latch.
Rotate duct inward to remove
Disconnect electrical harness to hood position switch.
Remove filter housing cover.
Release spring
loclc (B) on interior ventilation housing and
remove housing.

Downloaded from www.Manualslib.com manuals search engine
I Steerina and Wheel Alianment
Steering
system
Two types of steering gear are used in the E39 series models.
6-cylinder
(5251, 528i and 530i) models are equipped with
rack and pinion steering. The steering rack is mounted to
an aluminum subframe.
V-8
(540i) models are equipped with a recirculating ball
and nut steering gearbox mounted to a steel subframe.
At low speeds, maximum power assist is provided to ease
parking and city driving. At high speeds, assist is reduced to
ensure stability. The power steering system varies assist
based on engine speed.
Power boost for the steering is provided by an engine-driven
hydraulic pump. A hydraulic control valve is used to control
boost pressure.
The steering wheel connects to the steering gear via an ad-
justable steering column which incorporates a rubber cou-
pling ("guibo") to dampen vibration and noise.
Power steering fluid is supplied from the fluid
reservoir to the
pump and to the steering gear via rubberlmetal hoses.
The return line from the steering gear to the
reservoir loops
into the airstream in front of the radiator and connects to the
steering fluid cooler. The fluid cooler is attached to a cassette
which also includes cooling coils for engine oil, transmission
fluid and AIC condenser.
The steering gear requires no maintenance other than align-
ment and periodic inspection for worn components. Inspect
rubber rack boots
(rack and pinion system) and tie-rod end
boots periodically for tears or damage. Replace
if necessary.
-
NOTE-
The airbag system is traditionally referred to as Supplemen-
tal Restraint System (SRS). The
BMW versfon of SRS used
m the E39 models is known as the Multiple Restraint System - (MRS). - -

Downloaded from www.Manualslib.com manuals search engine
Steering and Wheel Alignment
Tightening torques
Tie rod
to Steering knuckle (replace self-locking nut) 65 Nm (48 it-lb)
to Steering rack 71 Nrn (52 ft-lb)
Outer tie rod end lock nut 51 Nrn (38 ft-lb)
Refer to the steering components illustration when perform-
ing the procedures below.
Steering gearbox system
components
(V-8 models
up to
911 999)
1. Tie rod end nut
2. Washer
3. Tie rod end
4. Steering fluid cooler
5. Tie rod end clamp bolt
6. Nut
7. ldler arm
8. ldler arm bushing
9. ldler arm bolt
10. Steering fluid reservoir
11. Hose clamp
12. Fluid supply line
13. Power steering pump
14. Fluid return line
15. O-ring seal
16. Banjo bolt
17. High pressure line
18. Center tie rod
19. Nut
20. Pitman arm
21.
Pitman arm pinch bolt
22. Nut
23. Fluid cooler supply line
24. Steering gearbox

Downloaded from www.Manualslib.com manuals search engine
340-32
Brakes
The procedure for removing the ABS I ASC or ABS I DSC hy-
draulic unit is similar for all models. The unit is located at the
right rear of the engine compartment.
- Using a clean syringe, empty brake fluid reservoir.
CAUTION-
Brake fluid is highly corrosive and dangerous to the environ-
ment. Dispose of it
properiw
4 Disconnect electrical harness connector (A) at hydraulic unit
(1998 DSC hydraulic unit in V-8 model shown).
Where applicable, detach electrical harness connector to
DSC pressure sensor.
Mark brake lines
(arrows) in relation to their placement on
hydraulic unit. Detach lines from unit using appropriate
sized flare wrench.
Seal open brake fluid lines and bores with suitable plugs to
prevent contamination.
- Carefully push aside brake lines from retainerslgrommets
that may be in the way of hydraulic unit removal. Use care not
to
kink brake lines.
- Remove hydraulic unit mounting screws. Remove hydraulic unit.
- If necessary, separate hydraulic unit from control module.
- Installation is reverse of removal, noting the following:
Check rubber mount for hydraulic unit/control module. Re-
place if damaged.
Make sure all nuts, fluid couplings, thread bores and mat-
ing surfaces are clean.
Avoid bending pins on control module harness connector
when reattaching.
Make sure brake lines are securely seated in grommets
before installing brake lines in hydraulic unit bores.
Bleed brakes using
BMW Service Testeras described earlier.
Tightening torques Brake lines to hydraulic unit
18 Nm (13 ft-lb)
DSC electronic control unit to hydraulic unit 2.9 Nrn (26 in-lb)
(use new screws)
Hydraulic unit to body
8 Nm (6 ft-ib)
Mounting bracket to hydraulic unit 8 Nrn (6 ft-lb)

Downloaded from www.Manualslib.com manuals search engine
OBD-11
On-Board Diagnostics
Automatic transmission diagnostic trouble codes (continued)
P-code
PO762
PO763
PO763
PO763
PO775
PO782
PO783 I I
PO795
PO798
PO962
PO963
PO966
PO967
PO970
PO971
BMW-FC
18
2 18
32
2
57
58
I I -
DTC Definition
Shift Solenoid 'C' Stuck On
Shift Solenoid
'C' Electrical
Shift Solenoid
'C' Electrical
Shift Solenoid
'C' Electrical
Pressure Control Solenoid
'B'
2-3 Shift
3-4 Shift
PO778 12 I Pressure Control Solenoid 'B' Electrical
3
3
1
1
2
2
3
3
PO973
PO979
PI 700
PI719
PI720
Pi731
PI732
PI734
Pressure Control Solenoid 'C'
Pressure Control Solenoid
'C' Electrical
Pressure Control Solenoid
'A' Control Circuit Low
Pressure Control Solenoid 'A' Control Circuit High
Pressure Control Solenoid
'6' Control Circuit Low
Pressure Control Solenoid
'0' Control Circuit High
Pressure Control Solenoid 'C' Control Circuit Low
Pressure Control Solenoid 'C' Control Circuit
High
PI734
PI738
Pi738
PO976 117 IShift Solenoid 'B' Control Circuit Low
16
18
62 144
129
51
65
1
PI743
PI743
PI743
PI746
PI746 - Pi747
Shift Solenoid 'A' Control Circuit Low
Shift Solenoid 'C' Control Circuit Low
Double Error Output Speed and
inputflurbine Speed
CAN Version Error
CAN
Timeout Control Module
Gear
1 manual Incorrect Ratio
Gear Monitoring 4 at Electrical Substitute Program
Pressure
Control Solenoid 'B' Eieclrical
2
3
29
PI747
PI747
Pressure Control Solenoid 'B' Electrical
Pressure Control Solenoid
'C' Electrical
Pressure Control Solenoid
'C' Electrical
4
5
51
83 104 Pressure Control Solenoid
'E' Electrical (M44lM52: Brake
Band Electrical)
Pressure Control Solenoid
'E' Electrical (M44lM52: Bralte Band Electrical)
Pressure Control Solenoid
'E' Electrical (M44lM52: Brake Band Electrical)
Transmission Control Module Output Stage
Transmission Control Module Output Stage
129 128 CAN-Bus Monitoring CAN-Bus Monitoring
144 CAN-Bus Monitoring