MAZDA 323 1992 Workshop Manual Suplement

Reading Wiring Diagrams
Loaic symbols I
ypes of logic symbols Operation Expressing output Simple relay circuits
OR
Input to A or 8 will Low electricai potential (L) at A and B +
produce output at C. no output (L) at C
A
6
D- High electrical potential (H) at A or B +
C output (H) at C
AND Input to A and B will High electrical potential (H) at A and B +
produce output at C. output(H) at C
q---J-c
Low electrical potential (L) at A or B + A
no output (L) at C
B a-00-a C
6
INV No input to A will produce Low electrical potential (L) at A -+
an output at B. no ground (H) B
An input to A will not High electrical potential (H) at A +
A- 6 produce an output at B. grounds (L) B A- 6
PROCESS Simplified representation of complex functions within circuit describes
main function. (Examples)
---
--I- 1 1. Igniters
I
-L-l Signal detector for engine control unit, cooling unit, and tachometer.
Ii- 2. r”~“-‘-‘-““‘~~‘.“’
Sbnsl conwflw :
i...-..--.---......-.~~
Signal converter for turn and hazard flasher unit and igniter unit.
Abbreviations used in this booklet
A
AAS
ABS
ACC
ACCEL
ACV
ADD
AE
AIS
ALL
ALT
EP
ANT
EV
EP
ATX
A/C
AIF
AIR
:AC
B/L
CARB
CCT
CIGAR
COMBI
CON
CONT
CPU
CSD
DEF
DOHC
ECPS Ampere
Autoadjusting Suspension
Antilock Brake System
Accessory
Accelerator
Air Control Valve
Additional
Acoustic Equilibration
Air Injection System
Automatic Load Leveling
Alternator
Amplitude Modulation
Amplifier
Antenna
Autostop
Alr Supply Valve
Automatic transmission
Atmospheric Pressure
Automatic Transaxle
Air Conditioner
Air Fuel
Auto Reverse
Battery
Bypass Air Control Valve
Bilevel
$rr$:,tor
Cigarette
Combination
Conditioner
Control
Central Procassino Unit
&Id-Start Device -
Defroster
Double-Overhead Camshaft
Electronically Controlled Power
Steering ECU
EGI
EGR
ELEC
ELR
ETR
EXH
E
FICB
FM
F/S
F/I
GEN
ET
HI
H/D
I;LUMl
INT
ISC
JB
LCD
LF
k!
z Engine Control Unit
Electronic Gasoline Injection
Exhaust Gas Recirculation
Electrio
Emergency Locking Retractor
Electronic Tuner
Exhaust
Front
Fast-Idle Cam Breaker
Frequency Modulation
Feedback
Fuel lniector
Generator
Heater
High-Energy Ignition
High
Heater/Defroster
Ignition
lllumlnation
Idle-Speed Control
Joint Box
Liquid Crystal Display
Left Front
Left Hand
Low
Left Rear
Low Wave
:I, Motor
Middle
MIL
MIN Malfunction Indicator Lamp
Minute
MIX
Mixture
MPX Multiplex
ZR Manual Transmission
MTX Mechanical Tuning Radio
Manual .Transaxie PRG
PTC
P/S ass
kc
FIF
. . .
RH
RPM
!2EL
SQ
ST
SW
TCV
TEMP
TICS
TR
TWS
V
VENT
VOL
VRIS
W Middle Wave
Normally Closed
Normally Open
Overdrive
Switch Off
Switch On
Power
Pressure Regulator Control
Solenoid Valve
Purge Solenoid Valve
Positive Temperature Coefficient
Heater
Power Steering
;im&k-Start System
Recirculation
Right Front
Right Hand
Revolutions Per Minute
Right Rear
Solenoid
Squares Per Milimeter
Start
Switch
Twin Scroll Turbocharger
Solenoid Valve
Temperature
Triple Induction Control System
Transistor
Total Wiring System
Volt
Ventilation
Volume
Variable Resonance Induction
System
Watt(s)
IO

Troubleshooting GI
Precautions to take when servicing an electrical system
l Note the following items when servicing the electrical system.
l Do not alter the wiring or electrical equipment in any way; this may damage the vehicle or cause a fire from
short-circuiting a circuit or overloading it. l
The negative (-) battery cable must be removed first and
installed last. l Do not replace with fuses exceeding specified capacity.
1OA
f5A
Zaution
o Be sure that the ignition and other switches are off
Caution
before disconnecting or connecting the battery
l Replacing a fuse with one of a larger capacity than
cables.
designated may damage components or cause a fire.
Failure to do so may damage the semiconductor
components.
0 Tape areas of the
l When mounting l Secure harnesses with provided clamps to take up slack.
harness that may rub or
components, be sure the
bump against sharp
harness is not caught or
edges to protect it from
damaged.
damage.
Zaution
B Clamp all harnesses near vibrating components
(for example, the engine) to remove slack and to
prevent contact resulting from vibration.
D Do not handle electrical components roughly or drop
them.
l Disconnect heat-
sensitive parts (for
example, relays and
ECU) when performing
maintenance (such as
welding) where
temperatures may exceed
80°C (176°F). l Make sure that the
connectors are securely
connected when
installed.
11

Gl Troubleshooting
Handling connectors
Caution
l Be sure to grasp the connectors, not the wires, when disconnecting them.
<CPU connector>
Improperly engaged
connectors will cause
poor terminal contact. A loose terminal Will
cause poor terminal 1 Baise the rear
2.Lift the tab with a
thin piece of metal
and remove the
Lift the tab with a thin
piece of metal and
there is no looseness in connector when engaged.
the female terminal.
1 .Raise the cover.
P.Lift the terminal to
B-Make sure the
terminal is securely
mounted in the
connector when
Pull lightly on individual
wires to check that they
are secured in the 1 Raise the cover.
2.Remove A.
3.Lift the tab with a
thin piece of metal
and remove the

Troubleshooting
Using electrical measuring equipment
Equipment USe
Test lamp Test to find open or shorted
H circ”its. operation Handling precautions 0 Connect the test lamp l Test lamps use 12V 1.4W
between the circuit being
or 3.4W bulbs or light-emitting
measured and a ground.
diodes (LEDs). Using .a large-
l The lamp will light if the circuit
capacity bulb may damage the
is energized to the point
CPU.
tested.
I? ‘s
n
Jumper wire
Used to create a temporary 0 Connect the jumper wire
l Do not connect the jumper
circuit. between the terminals of a wire from the power source
circuit to bypass a switch. line to a ground; this may
4 cause burning or other
b damage to harnesses or
electronic components.
M
Voltmeter
Used for measuring the voltage
l Connect the voltmeter in
of a circuit to find possible opens *Connect the positive (+) probe
parallel with the circuit.
or shorts.
to the Point where Voltage is to 0 Set the range to the desired
be measured and the negative
voltage.
(-) probe to a ground.
*Use the service hole when
measuring the voltage at the
diagnosis connector.
‘$$
‘, i_ I/
*Tie a thin wire to the positive
(+) probe to access narrow
terminals.
Ohmmeter
l Zero the ohmmeter.
Used to find opens and shorts in *Zero the meter after switching
the circuit, to confirm continuity l-.&j
to the measuring range.
and to measure resistance. -*-.
0 Before using the ohmmeter,
l Verify that voltage is not make sure the ignition switch
applied to the circuit. is off or the negative (-)
l Connect the probes between battery cable is disconnected
two points in a circuit. _ to prevent burning or
otherwise damaging the
ohmmeter.
Ammeter
l Connect the ammeter in series l Set the range to the desired
Used to check alternator output,
with the circuit by touching the amperage.
current supplied to the starter,
and dark current within a circuit. positive (+) probe to the l Connect the ammeter in series
power-side terminal and the with the circuit. The ammeter
Note
Dark current is the constant flow negative (-) probe to the
ground-side terminal. may be burned or otherwise
damaged if it is connected in
parallel.
of current while the ignition
switch is OFF.
13

Troubleshooting
Measuring voltage
lgnlgon switch
Voltmeter
Groind 2 -
Ground 1 Test lamp
or
If Connect a voltmeter or test lamp to the measuring points.
‘6 : Test lamp ON
x : Test lamp OFF
Weasuring voltage of connectors Poor contact
A voltmeter probe may momentarily connect a terminal wher
inserted into the connector and give an erroneous reading
when checking for improperly engaged connectors, poor
terminal contacts, or loose terminals.
Measuring voltage of ground
Touch the voltmeter probe to the ground wire when
checking the ground circuit.
Poor contact OK
14

Troubleshooting GI
Measuring continuity/resistance
Touch the ohmmeter probes to the switch terminals to check
Verify the operating state of the switch before checking
continuity because readings vary accordingly.
Note Continuity is checked according to the direction of the positive
(+) and negative (-) probes ofihe ohmmeter in the circuit
containing the diode.
Connection
I Continuity
Yes
The negative (- ) probe of the ohmmeter is
connected to the positive terminal of the internal
ohmmeter battery, the positive (+) probe to the
negative terminal of the battery. No
Connect the ohmmeter probes to the sensor or solenoid valve
terminals to check resistance.
Caution
Verify the operating state of the sensor before checking
resistance because readings vary accordingly.
1. Short between the terminals with a jumper wire to discharQe
the capacitor.
2. Set the ohmmeter range to xl Ok R and connect it to the
capacitor terminals.
3. The capacitor is good if the needle of the ohmmeter swings
once and returns to its original position.
15

GI Troubleshooting
FindIng short circuits
Shorts occur between the power (positive) and ground (negative) sides of a circuit.
Therefore, finding a short circuit requires determining how the circuit is routed.
Circuits
not connected to control unit
I
Examples
ihort location 1 SvmWom
I Battery
,pOSlhl
terminal) lgnitbn switch
I Finding short circuit
4
1. Remove the fuse and
main fuse of the circuit.
2. Disconnect ail connecton
Of electrical components in the circuit.
3. Attach a voltmeter or test
Motor
M
Qi!
Short (A)
Short (8)
Short (C)
Short (0) l The motor operates
regardless of whether the
thermoswitch is ON or OFF
when the ignition switch is ..-..
ON. -
@The fuse is not melted.
0 The main fuse melts when the
ignition switch and thermo-
switch are ON and the relay is
operating.
lgnitlon switch
Switch short locatior
Short (A)
Short (B)
Short (C) Test lamp lamp to the fuse box and
reconnect each connector, beginning
nearest the power
, source. Circuits connected to control unit
1 Examples
Symptom
l Fuse melts.
Short (D)
Short (E) 14. Check the voltmeter
reading or test lamp as
the connectors are
connected.
l solenoid A operates when the
ignition switch is ON.
l The CPU transistor burns out
when the ignition switch is
turned ON.
l The CPU thinks the switch is
ON because the same
conditions exist as when the
switch is ON.
@The CPU senses the sensor
to be 0 Q because the same
conditions exist as when the
resistance value is 0 Q.
l The CPU equipped with the
self-diagnosis function outputs
the code. l-
Finding short circuit
1. Remove the fuse and main
fuse of the circuit.
2. Disconnect ail connectors oi
electrical components in the
circuit.
rest lamp 3. Attach a voltmeter or test
lamp to the fuse box and
reconnect each connector,
beginning nearest to the
power source.
Check the voltmeter reading
or test lamp as the
connectors are connected.
Sensor/switch
1. Attach the test lamp or
voltmeter to the CPU
connector.
2. Connect to the switch/
sensor connector.
3. Check the voltmeter reading
voltmeter reads OV or the test lamp
16

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18 Y
l GROUND POINTS
WIRING ORDER INTO JOINT CONNECTOR MAY BE CHANGED
Jc-0 1 JOINT CONNECTOR F) JC-02 JOINT CONNECTOR (F)
JC-03 JOINT CONNECTOR (F)
m 6-l ”
6-n e-a
B B B B B 0 B B B B
B
0 B/G B B
JC-04 JOINT CONNECTOR (EM)
~~-06 JOINT CONNECTOR (EM)
JC-09 JOINT CONNECTOR (R)
a ”
*
*

0 FRONT
&Ii UNIT
@
1 0 5
88 0 5 EMISSION
//

//
//
@
//

JC-06

HARNESS SYMBOL : B
F) m (E) m (0 m 03 +++ PW E (IN) E (W
*** (EM) E (INJ)
19