1998 BMW 318ti Electrical Troubleshooting Manual





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0110.0 INTRODUCTION









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Schematics
The schematics divide the entire vehicle electrical system into individual circuits. Interacting
electrical components are shown on one common schematic.
Switches and other components are represented in such a way that their general layout and
function are self–explicit. They are arranged on the sheet such that the current path can be
followed from positive (top) to negative (bottom).
Important: The components and wires are not drawn to scale. For instance, a lead with a length
of over 1m can be shown as a lead that is only a few cm long. To ensure clear arrangement , all
connectors, lines branches and connected components from the fuses to the component and
from the component to ground connection are not shown within the individual cells. If required,
reference can be made to cells 0670.3 Fuse Details and 0670.4 Ground Distribution where all
lines are illustrated with all plug connections, line branches and connected components.
All circuit sysmbols used are listed and explained in cell 0140.0 Symbols.
In cell 7000.0 Component Location Chart all important connectors, ground points and
components are listed in tabular form. It provides a precise description of the component
locations in the vehicle.
In cell 7100.0 Component Location Views the location of connectors and components which
are difficult to locate are shown in line arts or illustrations. In cell 8000.0 Splice Location Views
all splices are listed in numerical order and illustrations are provided to assist in locating splices
on larger harnesses. In cell 8500.0 Connector Views diagrams of connectors with more than 2
pins are illustrated.
Included in this ETM are foldout block diagrams. These are overviews of the entire system (EGS,
ABS, AC etc.) which helps understand the relationships between various components and control
unit of the system being diagnosed.

Example
General conventions can be explained based on the following schematic example.
 




INTRODUCTION







General Conventions
1. Switches and relays are always shown in rest position (e.g. K11).
2. A component shown in a dashed frame signifies that the component is
illustrated only in part (e.g. P90 and P91).
3. A component shown in a completely drawn frame signifies that the
component is illustrated in full (e.g. K11).
4. The dashed line between pin 8 and pin 6 of connector X293 indicates
that both pins belong to connector X293.
5. The dashed line from fuse F1 to pin 8 of connector X293 shows the
positive supply of relay K11. If required, refer to cell 0670.3 Fuse Details at
fuse F1 for the complete line progressing with plug connections, line
branches, wire colors and cross sections.6. The dashed line with an arrow at splice X452 indicates that several wires
lead to splice X452. All lines leading to the connection are illustrated in
cell 6100.0 Central Body Electronics (ZKE). An interrupted line with an
arrow indicates that only this one wire leads to another circuit.
7. The dashed line from pin 4 of connector X293 to ground X493 shows the
ground supply for relay K11. If required, refer to cell 0670.4 Ground
Distribution at ground X493 for the complete line progression with all plug
connections, line branches, wire colors and cross sections.
8. The interrupted line from splice X452 with an A in the open arrow is
continued on page 6160.0–02.
Termination of wire 4 VI/SW from splice X452 with a wavy line indicates that
the wire is continued on the opposite page.
 


 







!



CIRCUIT BREAKERVARIABLE RESISTANCE
SENSOR VARIABLE
CONTACT IS MOVED BY
AN EXTERNAL FORCE
VARIABLE RESISTOR
RESISTANCE IS
CHANGED BY
TEMPERATURE OR
PRESSURE
DIODE CURRENT
CAN FLOW ONLY IN
DIRECTION OF
ARROW
ZENER DIODE TO
REGULATE VOLTAGE
LIGHT EMITTING
DIODE PERMANENT MAGNET
MOTOR ONE SPEED
PERMANENT MAGNET
MOTOR TWO SPEEDS
SOLENOID
SOLENOID CONTROLLED
VALVE OR CLUTCH
SOLENOIDTRANSISTORIZED
SWITCH HEATING ELEMENT
OXYGEN SENSORCONTROL/POWER
ELECTRONICS
RADIO LOUDSPEAKER OR
HORN
LIGHT BATTERY
FUSIBLE LINK
FUSE DETAILS
INDUCTIVE
SENSOR
KNOCK SENSOR
31


VEHICLE SPEED
SENSOR

THERMO SWITCH
HALL EFFECT
SENSOR
ANTENNA
0140.0 SYMBOLS


 







!


A WAVY LINE
MEANS WIRE IS
CONTINUED
ENTIRE COMPONENT
SHOWN
COMPONENT WITH
SCREW TERMINALS
CONNECTOR
ATTACHED TO
COMPONENT
PART OF COMPONENT
SHOWN
.75 BR.5 BR
X270
4
.5 BR
.5 BR
3
.5 BR.5 BR
X270
4
.5 BR
.75 GN/WS CONNECTOR
ATTACHED TO
COMPONENT LEAD
(PIGTAIL)
COMPONENT CASE
ATTACHED
DIRECTLY TO
METAL PART OF
CAR (GROUNDED)
WIRE ATTACHED
TO METAL PART
OF CAR
(GROUNDED)
GROUND NUMBERED
FOR REFERENCE ON
COMPONENT LOCATION
CHART
WIRE SIZE IN MM
SQUARED
BL BLUEWIRE COLOR
BR BROWN
GE YELLOW
GN GREEN
GR GRAY
OR ORANGE
RS PINK
RT RED
SW BLACK
VI VIOLET
WS WHITE
ONE POLE, TWO
POSITION SWITCH
SWITCHES THAT
MOVE TOGETHER
DASHED LINE
SHOWS A
MECHANICAL CON-
NECTION
BETWEEN
SWITCHES
TR TRANSPARENT
CONNECTOR REFERENCE
NUMBER FOR COMPONENT
LOCATION CHART
TWO CONNECTIONS
(PINS) IN THE SAME
CONNECTOR
DASHED LINE INDICATES
TERMINALS OF THE
SAME CONNECTOR
12
X165
1212
SYMBOLS

WIRE INSULATION
IS ONE COLOR
PIN NUMBER
WIRE INSULATION
IS ONE COLOR
WITH ANOTHER
COLOR STRIPE
(GREEN WITH
WHITE)


 







!


4 RT
15
4 GN13
.5 GN/WS5
2.5 SW/GE 2.5 VI42
DETAILS ABOUT
COMPONENT OR
OPERATION
”R” IS ENERGIZED IN
ACCY, RUN, OR START 76 82 X33CONTACT RELAYRELAY WITH
RESISTOR
ACROSS WINDINGTERMINAL NUMBER THREE POLE,
FOUR POSITION
SWITCHCOMPONENT NUMBER
S2
IGNITION SWITCH
0) OFF
1) ACCESSORY
2) RUN
3) START
TERMINAL NUMBER DESCRIPTION
50 VOLTAGE: IGNITION
SWITCH IN START
VOLTAGE: SUPPLIED
AT ALL TIMES
VOLTAGE: IGNITION
SWITCH IN RUN OR
START 30
15
15I
50 R30
INDICATES THAT FUSE
9 IS SUPPLIED WITH
POWER AT ALL TIMES
CONTACT RELAY WITH
TWO OUTPUTSCHANGEOVER
RELAY WITH TWO
OUTPUTS
TERMINAL NUMBER DESCRIPTION
30 RELAY INPUT
RELAY OUTPUT
(WINDING)
RELAY INPUT
(WINDING)
RELAY OUTPUT
(ENERGIZED)
RELAY OUTPUT
(AT REST) 85
86
87
87a
30 86
87 87 8530 86
87 85 87a
TERMINAL NUMBER DESCRIPTION
VOLTAGE: IGNITION
SWITCH IN RUN
VOLTAGE: IGNITION
SWITCH IN ACCESSORY,
RUN OR START 15I
R
GROUND 31
POWER STATUS DESCRIPTION
VOLTAGE: SUPPLIED
AT ALL TIMES
VOLTAGE: IGNITION
SWITCH IN RUN OR
START
VOLTAGE: IGNITION
SWITCH IN ACCESSORY,
RUN OR START
30 86
87 8530
86
87 85NAME OF COMPONENT
F915A
2
10
32
10
32
10
3
SYMBOLS

SYMBOLS









!


1.5 BR DATA LINK
0670.5 .5 WS/GE
0670.0-030670.0-02
1.5 BRN9
RADIO
THE COMPLETE WIRE
PROGRESSION AND
FURTHER CIRCUITS
CONNECTED TO
GROUND X497 ARE
SHOWN IN CELL
”0670.4 GROUND
DISTRIBUTION” AT
GROUND X497
THE COMPLETE WIRE
PROGRESSION AND
FURTHER CIRCUITS
CONNECTED TO FUSE
18 ARE SHOWN IN CELL
”0670.3 FUSE DETAILS”
AT FUSE 18
CURRENT PATH IS
CONTINUED AS
LABELED P90
FRONT POWER
DISTRIBUTION BOX F18
15A
GROUND
DISTRIBUTION
0670.4
N1
ANTI–THEFT
CONTROL MODULE
(DWA) FUSE DETAILS
0670.3A1
GENERAL MODULE
X252
17X332
2
CIRCUIT REFERENCE–A
WIRE WHICH CONNECTS
TO ANOTHER CIRCUIT
A2
INSTRUMENT
CLUSTER
X16
11RXD
ARROW SHOWS
DIRECTION OF
CURRENT FLOW
AND IS REPEATED
WHERE CURRENT
PATH CONTINUES
X497
X1812615
X491
 


BLOCK DIAGRAM






!


SYMBOLS
A1
GENERAL MODULE
228 17 118 9
C
6160.0 6160.0C
M17
LUGGAGE COMPARTMENT
LOCK MOTOR
23 20M12
DRIVER’S DOOR
LOCK MOTOR
N17
CRASH CONTROL
MODULE
N1
ANTI–THEFT
CONTROL MODULE
(DWA) 5126.0 5126.0
6575.1
A
54
S5
WIPER/WASHER
SWITCH 6160.0 6160.0 6160.0
M3
WIPER MOTOR
1C
S14
DRIVER’S DOOR
JAMB SWITCHS15
REAR RIGHT DOOR
JAMB SWITCH
S16
LEFT REAR DOOR
JAMB SWITCH S13
PASSENGER’S
DOOR JAMB
SWITCH 15
3
2A
P91
REAR POWER
DISTRIBUTION BOX
6
PIN AND
CONNECTOR NUM-
BERS ONLY ON
THE CONTROL
MODULE
DASHED LINE INDICATES
THAT FURTHER CIRCUITS
ARE IN THE PATH
BETWEEN COMPONENT
AND CONTROL MODULE
EXAMPLE: CONNECTORS
C PIN 17 AND C PIN 11 GO
TO M17, CONNECTORS A
PIN 23 AND A PIN 20 GO
TO M12
A
THIS CELL CONTAINS A
DETAILED INFORMATION OF
THE PATH BETWEEN COM-
PONENT AND CONTROL
MODULE
B
AD
COMPONENTS
WITHOUT PIN OR
CONNECTOR NUM-
BERS
EXAMPLE:
CONNECTOR C PIN 1
GOES TO S13,
CONNECTOR B PIN 15
GOES TO S14
DESCRIPTION OF THE
CONTROL MODULE
CONNECTORSX253
X255X332
X254BCD
=
=
=
=
F317.5A6100.0-03COMPONENT IS
SHOWN IN CELL
ON PAGE AS
LABELED
 

11 12 13456 78 9
38
37
35
34
33
32
31 42
41
40
39 43 44


FRONT POWER DISTRIBUTION BOX
0670.0 POWER DISTRIBUTION CHART




!



K2
HORN RELAYK47
FRONT FOG LIGHT
RELAYK48
LOW BEAM LIGHT
RELAYK16
HAZARD FLASHER
RELAYK4
BLOWER RELAY
K13
REAR DEFOGGER
RELAYK125
ABS PUMP MOTOR
RELAY, TIMEDK22
HIGH SPEED
RELAYK19
COMPRESSOR
CONTROL RELAYK21
NORMAL SPEED
RELAY K6301w
FUEL PUMP RELAY K6300
ENGINE CONTROL
MODULE RELAY
X56X44X45X64X58
X292X11393
X53X51X52
X6304X6301X630046
45
3612 3 10
14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30
FUSES FUSES
X0
 

K6304
SECONDARY AIR
PUMP RELAY