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/ Fuel Tank and Fuel Pump - .. -. -- 1
Fuel pump fuse and relay
Troubleshooting of any fuel pump fault should begin with
checking the fuel pump fuse and the fuel pump relay. The
DME main relay should also be checked. The fuel pump relay
is located behind right side luggage compartment interior
panel.
I Fuel pump relay
BLU =blue ERN = blo$,m GRN =groan GRY = grsy ORG =orange PNI< =pink RED =red VIO =violel WHT = wlilte
rk-; I I 1 ECM
I I I 31 8 ,._--___.I
NOTE-
Special tools are required for some of the tests described
here.
4 Fuel pump circu~t is fuse-protected.
0 6-cylinder models with Siemens DME MS41 .I, MS42, V-8
models with Bosch DME M5.2, M5.2.1 englne manage-
ment: Fuse
F54,15A (luggage compartment fuse panel)
6-cylinder models with Siemens DME MS43 engine man-
agement: Fuse
F22,25A (glove compartment fuse panel)
V-8 models with Bosch DME M7.2: Fuse F54,25A (lug-
gage compartment fuse panel)
- Fuse 31 in glove compartment fuse panel supplies power to
coil side of fuel pump relay. Engine control module (ECM)
supplies switched ground to relay. During starting, fuel pump
runs as long as ignition switch is in START position and con-
tinues to run once engine starts. If electrical system fault in-
terrupts power to fuel pump, engine will not run.
. .
Operating fuel pump for tests
- To operate fuel pump for testing purposes without having to
run engine, bypass fuel pump relay to power pump directly.
< To run fuel pump, open luggage compartment and release
right side trim panel.
![BMW 540i 2001 E39 Workshop Manual Downloaded from www.Manualslib.com manuals search engine
- Fuel Tank and Fuel pump]
Remove fuel pump
relay (arrow).
4 Connect relay socitet terminal 6 (redlviolet wire) to relay
socket termi BMW 540i 2001 E39 Workshop Manual Downloaded from www.Manualslib.com manuals search engine
- Fuel Tank and Fuel pump]
Remove fuel pump
relay (arrow).
4 Connect relay socitet terminal 6 (redlviolet wire) to relay
socket termi](/manual-img/1/2822/w960_2822-476.png)
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- Fuel Tank and Fuel pump]
Remove fuel pump
relay (arrow).
4 Connect relay socitet terminal 6 (redlviolet wire) to relay
socket terminal
2 (whitelblue wire) with a fused jumper wire.
After completing tests, remove jumper harness.
CA
UTIOG
Relay locations may vary Use care when identifying relays
and making electrical checks at
the fuse/relay panel. See
610 Electrical Component Locations for additional re-
lay information.
The fuel pump relay has a 1.5
md red/violet wire at
terminal
6 in the relay socket. Terminal2 has a 2.5md
white/blue wire. See ELE Electrical Wiring Diagrams
for additional wiring information.
NOTE-
* The fuel pump will run as soon as the jumper wire Is at-
tached.
The jumper wire should be 1.5
md (14 ga.) and include
an in-line fuse holder with a 15A fuse. To avoid
fuse/relay
panel damage from repeated connecting and disconnect-
ing, also include a toggle switch in the jumper harness.
- If pump does not run with jumper installed, fault could be in
fuel pump, fuses
F31 or F22 1 F54, or wiring to pump. Check
pump, fuses and its wiring as described below.
Fuel pump electrical circuit, testing
- The test given below assumes that the fuel pump relay circuit
is functioning correctly as described earlier. Access to the
pump is from below the rear seat bottom cushion.
- Remove rear seat lower cushion by lifting front edge off left
and right catches.

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160-8
I Fuel Tank and Fuel Pump
4 Disconnect harness connector from tank sending unit by
sliding connection lock to release connector.
Connect voltmeter between fuel pump terminals on
connector.
NOTE-
Fuel pump power (+) is supplied through the white/blue wire
Ground
(-) is supplied by the brown wire.
With jumper wire connected in place of fuel pump relay as
described above, check for battery voltage at fuel pump
harness connector terminals.
If voltage and ground are present, fuel pump is probably
faulty. If there is no voltage, check wiring between fuel pump
and relay.

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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.

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On-Board ~ia~nosticsl
Engine diagnostic trouble codes: M62 engine (continued)
P-code
I I -
I I - -.
PI445 1186 / Diagnostic Module Tank Leakage (DM-TL) Pump Control Circuit Signal Low
PI357
PI382
PI386
PI413
PI414
PI441
PI442
PI443
PI444
P1356 1 53 I Misfire during Start Cylinder 8
BMW-FC
I P1523
I
I - -
1165 I 'A' Camshaft Position Actuator Signal Low (Banlc 1)
Explanation
P1381 1215 I Control Module Self-Test, Knock Control Onset (Bank 1)
53
21 6
21 4
84
84
1
1
1
186
PI 446
PI 447
PI 448
PI449
PI 450
PI451
PI452
PI476
Misfire Cylinder 8 with Fuel Cut-Off
Control Module Self-Test, Knock Control Test Pulse (Bank 1)
Control Module Self-Test, Knock Control Circuit Baseline Test (Bank 1)
Secondary Air Injection Pump Relay Control Circuit Signal Low
Secondary Air Injection Pump
Relay Control Circuit Signal High
Leakage Diagnostic Pump Control Open Circuit
Leakage Diagnostic Pump Control Circuit Signal Low
Leakage Diagnostic Pump Control Circuit Signal High
Diagnostic Module Tank Leakage (DM-TL) Pump Control Open Circuit
186
189
189
189
2
2
2
184
P1524
P1525
P1526
PI527
PI528
PI633
PI 634
PI 635
I I
PI 638 / 131 I Throttle Valve Position Control Throttle Stuck Temporarily
. -
Diagnostic Module Tank Leakage (DM-TL) Pump Control Circuit Signal High
Diagnostic Module
Tank Leakage (DM-TL) Pump Current Too High during Switching Solenoid Test
Diagnostic Module Tank Leakage (DM-TL) Pump Current Too Low
Diagnostic Module
Tank Leakage (DM-TL) Pump Current Too High
Diagnostic Module Tank Leakage (DM-TL) Switching Solenoid Control Open Circuit
Diagnostic Module
Tank Leakage (DM-TL) Switching Solenoid Control Circuit Signal Low
Diagnostic Module
Tank Leakage (DM-TL) Switching Solenoid Control Circuit Signal High
Leakaqe Diaqnostic Pump Clamped Tube
I I
165
165
166
166
166
136
133
134
'A' Camshaft Position Actuator Control Circuit Signal High (Banlc 1)
'A' Camshaft Position Actuator Control Open Circuit (Bank 1)
'A' Camshaft Position Actuator Control Open Circuit (Bank 2)
'A' Camshaft Position Actuator Control Circuit Signal Low (Bank 2)
'A' Camshaft Position Actuator Control Circuit Signal High (Bank 2)
Throttle Valve Adaptation Limp-Home Position Unknown
Throttle Valve Adaptation Spring Test Failed
Throttle Valve Adaptation Lower Mechanical Stop not Adapted
Throttle Valve Control Circuit
PI 636
PI639
P1643
P2088
P2089
PI 637 / 130 I Throttle Valve Position Control, Control Deviation
132
131
135
165
165 Throttle
Valve Position Control Thronle Stuck Permanently
Throttle Valve Actuator Start Test Amplifier Balancing Plausibility
'A' Camshaft Position Actuator Control Circuit Low (Banlc 1)
'A' Camshaft Position Actuator Control Circuit High (Bank 1)