2000 BMW 528i Diagrams

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- Fuel Injection
ECM relay, testing
The engine control module (ECM) relay is energized via the
ECM and supplies battery positive
(B+) power to many of the
engine
management components and subsystems. If this re-
lay is faulty, the engine will not start.
CAUTIOI\C
Relay positions can vary. Be sure to confirm relay position by
identifying the wiring
in the socket using the wiring diagrams
in ELE Electrical Wiring Diagrams.
NOTE-
The ECM relay is also referred to as the DME main relay.
ECM relay powers:
* ECM
Ignition coils
Fuel injection
Evaporative leak detection pump
(5.2.1 only)
Idle air actuator
Camshaft sensors Evaporative emissions valve
Hot film mass air flow sensor
Fuel pump relay
Oxygen sensor heaters
4 Working in right rear of engine compartment:
Release interior ventilation filter cover latch
(A) and re-
move cover.
Release plastic locking tab
(B).
Rotate duct inward (arrow) to unloclc from bulk head and
remove duct.
0 Release spring lock (C) to remove lower filter housing.
Slide filter housing away from inner fender to remove.
- Remove electrical box (E-box) cover fasteners and remove
cover.

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130-50
Fuel Injection
Bosch M5.2
ECM relay
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< With ignition off, remove ECM relay (arrow) in electronics
box (E-box) at right rear of engine compartment.
NOTE-
Relay locations can vary. Conh relay identification by
matcliing wiring colors and terminal numbers.
4 Check for voltage at terminal 6 of main relay socket (30-red
wire). On M5.2 cars also check for battery voltage at terminal
8.
. . . . . . . . . ,
If battery voltage is present, continue testing
.
If battery voltage is not present, check large red wire(s) in
relay socltet. See
ELE Electrical Wiring Diagrams.
%P,,tt
- Reinstall relay and turn ignition on. Gain access to underside
of relay socket and
checlc for ground at terminal 4 (85-brown
wire).
. . . . . . . . . . . . - - - - - - - - - . - - - . . l ,,-. ; Engine i f .: , ; Fuse carrier .,A . :engine /;is? /control L.!.!! .... 1.: ...... !.::..! I lij :module electronics If
ground is present, continue testing
If ground is not present, signal from ECM is missing. Checic
wire between ECM and relay.
4 With ignition on and relay installed, check for battery voltage
at terminal
2 (87-redlwhite wire). On M5.2.1 cars also checlc
for battery voltage at terminal 5.
If battery voltage is present, relay has energized and is
functioning correctly.
If battery voltage is not present and all earlier tests are OK,
relay is faulty and should be replaced.

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130-51
Fuel Injection
Oxygen sensors, checking
The oxygen sensor provides an input voltage signal [0.2 vdc
(lean) to 0.8 vdc (rich)] to the
ECM based on the oxygen con-
tent in the exhaust gas. To generate voltage, the sensor tem-
perature must exceed 575"
F (300" C). Therefore the sensor
is electrically heated.
NO JE -
The test given below is not a conclusive test of oxygen sen-
sor efficiency and does not test how the oxygen sensor re-
acts to changing conditions. Pin numbers and wire colors
can vary Always check the wiring diagrams to confirm wire
color and pin assignment.
0 The oxygen sensorconnectorplugs are locatednext to the
catalytic converters.
With connector attached to sensor, connect digital voltmeter
between
A and B wires in connector.
WARNING -
Exhaust manifolds andpipes can be hot enough to cause se-
rious burns. Wear suitable heavy gloves and other appropri-
ate protection.
NOJE-
Connector style may vary depending on system application.
Consult wiring diagram for system-specific wiring. See
ELE
Electrical Wiring Diagrams.
Start engine.
A fluctuating voltage signal should show on the
meter.
If voltage is incorrect, turn engine off and check pre-
heater circuit as described below.
NOJE-
To check sensor response to lean and rich mixtures, create
an air leak.
Oxygen sensor
voltage at idle
- Connect digital voltmeterbetween sensor heaterwires (white
wires,
C and D). Start engine and check for battery voltage.
If voltage is not present, check oxygen sensor heater fuses.
0.2 to 0.8 vdc fluctuating
NOJE-
The oxygen sensor heater is powered via fusedpositive (+)
battery voltage and a switchedground from the ECM. See
ELE Electrical Wiring Diagrams for specific circuit informa-
tion.
- The ground side of the oxygen sensor heater circuit is pulsed
on and off by the
DME control module.

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130-54
I Fuel Injection ldle speed control valve,
testing and replacing
ldle speed is maintained by the ECM through the idle speed
control valve. The idle control function compensates for en-
gine load and engine operating conditions. ldle speed is
adaptive through the ECM and no adjustments can be made.
Before checking valve, confirm that throttle position sensor is
working correctly.
NOTE-
The test given below is an electrical check only. It does not
check the mechanical operation of the valve. If the valve is
sticking, hanging up or is sluggish in operation, substituting a
Inown good valve is the best way to check it.
With engine running, check that idle speed control valve is
buzzing.
Turn on
AIC or shift car into drive. ldle should remain steady
or increase slightly.
If valve is not buzzing, or if idle decreases in step above, stop
engine and disconnect harness connector from valve.
4 Check resistance of valve across its terminals. Test values
are listed below.
ldle speed control valve coil resistance
Terminals
1 and 2 20 +2%
Terminals 2 and 3 20 +2Q
Terminals 1 and 3 40 +4%
NOTE-
If you suspect an intermittent fault, lightly tap the valve while
testing resistance.
With valve harness connector disconnected, check for bat-
tery voltage at redlwhite wire in connector with ignition on.
If . ~~ ~~
there is no voltage, check wiring between connector and 7 ECM relay. See ELE Electrical Wiring Diagrams.
NOTE- - The idle speed control valve receivespositive (+) battery volt-
age from the ECM (DME main) relay

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Fuel Injection
When system faults are detected, a diagnostic trouble code
(DTC) is stored in the engine control module (ECM). The MIL
also illuminates
if an emissions-related fault is detected.
When faults arise, or
if the malfunction indicator lamp (MIL) is
illuminated, begin troubleshooting by connecting BMW ser-
vice tester
DISplus, MoDiC, GTl or equivalent scan tool. The
capabilities of OBD
II software has the potential to save hours
of diagnostic time and to help avoid incorrect component re-
placement and possible damage to system components.
CA UTIOI\C
The tests in this section may set fault codes (DTCs) in the
ECM and illuminate the MIL. After all testing is completed,
access and clear DTC fault memory using an OBD
I1 or
BMW compatible scan tool. See OBD On-Board Diag-
nostics.
. Only use a digital multimeter for electrical tests.
Relay positions can vary. Be sure to confirm relay posi-
tion by identifying the wiring in the
socket using the wir-
ing diagrams found in ELE Electrical Wiring
Diaqrams.
NOTE-
= OBD I1 fault memory (including an illuminated MIL) can
only be reset using the special scan tool. Removing the
connector from the ECM or disconnecting the battery will
not erase the fault memory.
0 The BMW-dedicated 20-pin diagnostic link connector
(DLC) is in the right rear of the engine compartment. The
20-pin DLC was eliminated on models after
6/2000.
The 16-pin OBD I1 diagnostic connector (arrow) is located
inside the car on the lower left dash panel.

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130-70
Fuel Injection
ECM relay
--
CAUTION-
Relay positions can vary Be sure to confirm relay position by
identifying the wiring in the
socl(et using the wiring diagrams
in ELE Electrical Wiring Diagrams.
Working in right rear of engine compartment:
Release interior ventilation filter cover latch
(A) and re-
move cover.
Release plastic locking tab
(B).
Rotate duct inward (arrow) to unlock from bulk head and
remove duct.
Release spring
loclt (C) to remove lower filter housing.
Slide filter housing away from inner fender to remove.
- Remove electrical box (E-box) cover fasteners and remove
cover.
4 With ignition off, remove main relay (arrow) in electronics
box (E-box) at right rear of engine compartment.
NOTE-
Relay locations can vary Confirm relay identification by
matching wiring colors and terminal numbers.
4 Check for voltage at terminal 6 of main relay socket (30-red
wire).
If battery voltage is present, continue testing.
If battery voltage is not present, check large red wire in re-
lay socltet. See ELE Electrical Wiring Diagrams.
- Reinstall relay and turn ignition on. Gain access to underside
of relay socket and check for ground at terminal
4 (85-brown
wire).
If ground is present, continue testing.
If ground is not present, switched ground signal from ECM
is missing. Check wire between ECM and relay.
- With ignition on and relay installed, check for battery voltage
at terminal
2 (87-redlwhite wire).
If battery voltage is present, relay has energized and is
functioning correctly.
If battery voltage is not present and all earlier tests are OK.
relay is faulty and should be replaced.

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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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180 Exhaust System
General Exhaust System
. . . . . . . . . . . . . . . . .
Exhaust system, removing and installing
Muffler, replacing..
. . . . . . . . . . . . . . . . .
Exhaust Manifolds . . . . . . . . . . . . . . .
Exhaust manifolds, removing
and installing (M52 engine)
. . . . . . . . . .
Exhaust manifolds, removing and
installing (M52
TU and M54 engines) . . .
Exhaust manifolds, removing
and installing (M62 engine)
. . . . . . . . . .
Oxygen Sensors. . . . . . . . . . . . . . . . . . . . 180-9
Oxygen sensors (precatalyst),
replacing
(M52 TU and M54) . . . . . . . . . . . . 180-9
Oxygen sensors (post-catalyst),
replacing (M52
TU and M54) . . . . . . . . . . . . 180-9
Oxygen sensor, replacing
(M52 and M62 engine) . . . . . . . . . . . . . . . 180-10
Exhaust System Diagrams . . . . . . . . . 180-1 1
M52 engine (528i 1997-1 998) . . . . . . . . . . 180-1 1
M52
TU and M54 engines
(528i 1999-2000 and 5251 2001-2003) . . . 180-1 2
M54 engine
(530i 2001-2003) . . . . . . . . . . 180-1 3
M62 engine
(540i 1997-1 998) . . . . . . . . . . 180-1 4
M62
TU engine (540i 1999-2003 . . . . . . . 180-1 5