1992 MAZDA 323 relay

F3 SELF-DIAGNOSIS FUNCTION
:ODE NO. 25 {SOLENOlD VALVE - PRESSURE REGULATOR CONTROL) (Low temperature opoeration)
INSPECTION ACTION
Disconnect connector from ECU; IS there battery Yes Check ECU termrnal connector for poor
voltage at ECU terminal 2T (G/C) wrth Ignition connection
switch ON?
4 If OK, replace ECU
CT page F3-2
c3 If not OK, repatr or replace connector
NO Go to next step
2 In same condition as rn Step 1. is there battery Yes Repair or replace wlrrng harness (G/O)
voltage at sofenord vatve (PRC low temp.) con-
nector termrnal wrre (G/O)?
NO Go to next step
3 Is solenord valve (PRC low temp ) UK7 Yes Check for a short or open crrcuit in WII-
CT page F343 ing harness (main relay [FUEL INJ re-
lay] - solenoid valve [PRC low temp.])
NO Replace solenord valve (PRC tow temp.)
1
t3EOF3-323
CODE NO. 35 (SOLENOID VALVE - PRESSURE REGULATOR CONTROL) (High temperature opoeration)
STEP lNSPECTlON ACTlON
1 Disconnect connector from ECU: is there battery Yes Check ECU terminal connector for poor
voltage a? ECU terminal 22 (G) with rgnttlon connection
swttch ON7
4 If OK, replace ECU
J page F3-2
e If not OK, repair or replace connector
No Go to next step
2 In same condrtron as In Step 1, is there battery Yes
voltage at solenoid valve (PRC high temp.) con- Repair or replace wiring harness (G)
nector terminal wire (G)?
No Go to next step
3 Is solenoid valve (PRC high temp ) OK7 Yes Check for a short or open circuit In wir-
r;r page F343 ing harness (marn relay [FUEL INJ re-
WI - sofenord valve [PRC high temp.])
No Replace solenoid valve
(PRC high temp.)
f3EOF3-324
Circuit Diagram
ECU
I
2T 22 I
G
TO MAIN RELAY
I SOLENOID
VALVE
(PRC HIGH TEMP.)
F3-18 :3EOf3 32 5
--
TRW
RELAT
c
-..


INPUT
--
KNOCH
--
DIAGM
(TEN T
--
IGNITIi
(STAR1
--
E/L SIC
-a
P/S PR
--
A/c SYI
--
NEUTR
SWITCI
--
STUPb
--
ATMDI
SENSQ
-a
THRUI
-..
INfAk.1
--
AlFlFLC
--
UXYGE
--
WATEF
--
DlSfRl

F3 TROUBLESHOOTING GUIDE
SYMPTOM TROUSLESHOOTING
2 . CRANKS NORMALLY BUT WILL NOT START (NO COMBUSTION)
LIESCRIP-
l Engine cranks at normal speed but shows no sign of firing l Battery in normal condition
TION *Throttle valve not held fufly open while cranking (dechoke system not operating}
l Fuel in tank
UROOBLESHUOTlNG HINTS]
@ No spark
@.I low fuei tine pressure
l Ignition control malfunction @I Low engine compresslon l Ignition system component malfunction
@ No fuel injection
l Fuel pump inoperative l Ihjectors inoperative
;TEP
INSPECTION
I ACTION
1
Is strong btue spark visible at disconnected high- Yes Go to Step 3
tension lead?
NO Go to Step 2
2 Is “00” dlsplayed on Self-Dlagnosjs Checker
Yes
with ignltron switch ON? Check rgnltion system (Refer to
Troubleshooting “Misfire”)
c7 Section G
SYSTEM SELECT: 1 No
Service Code No. displayed Check for cause (Refer to specified
check sequence)
G- page
F3-16
“66” flashes
Check ECU termrnal 1F voltage
3 page W-45

Voltage: Battery vabage
(ignition switch ON)
W: SELF TEST C+ If OK, replace ECU
4 If not OK, check wiring
CT page F3-2
(ECU
- Self-Diagnosis Checker)
3
Connect diagnosis connector terminals F/P and
Yes
GND with jumper wire; IS fuel pump operating Does engine start in this condition?
sound heard wjth ignition switch ON?
4 If it does, check circuit-opening
relay
4 If it does not, go to Step 5
No Go to next step
F3-22
iTEF
6
8

TROUBLESHOOTING GUlDE F3
STEP INSPECTION ACTlON
4
Is there buttery voltage at fuel pump connector Yes
* (G/R) with lgnitron switch ON and F/P terminal Check contmurty of fuel pump
between termrnafs G/R and 8
Check ctrcutt openmg relay
5
Is qector operating sound heard whtle engine IS Yes Go to Step 8
being cranked?
No Go to next step
CcI page F3-45
+ If 0K;check for a short cjrcult rn
wiring harness
(Injector reastor-Injector)
=D If not OK, replace Injector reststor
fuel Line pressure: 265-314 kPa
12.7-3.2 kgflcd, 38-46
psi)
if fuel return hose is clogged or
t, replace pressure
CT psge F3-3
F3-2 3

TROUBLESHOOTING GUIDE F3
8
1 ROUGH IDLE/ENGINE STALLS AT IDLE - ALWAYS
DESCRtP- 1 l Engine starts normally but stalls or vibrates excessively at idle in every condition
TION
[TROUBLESHOOTiNG HlNTSJ @ Air/Fuel mixture tw lean @ Incorrect idle-speed l ldiespeed misadjustment l Idle-speed control malfunction
$I One or more spark plugs not firing
9 Low engine compression
B Airflow meter stuck l Air leakage l Fuel injection control malfunction
*Low fuel line pressure
@ One or more injectors clogged or not
@ Low intake air amount operating
INSPECTION
Is “00” displayed on Self-Diagnosis
Checker with ignition switch ON?
1
SYSTEM SELECT: 1
ACTION
Go to next step
Service Code No. displayed Check for cause (Refer to specified
check sequence) c7 page F3-16
“88” flashes
Check ECU terminal IF voltage
(17 page F345
--.
‘\.
Voltage: Battery v&age
(Ignition switch ON)
4 If UK, replace ECU IT page F3-2 c3 If not OK, check wiring
(ECU - Self-Diagnosis Checker) Y -SELECT SW: A
Are ECU terminal voltages OK
(especially 20, 20, and ZQ)?
D page F3-45 Yes
Gu to next step
NO Check for cause
Disconnect each high-tens&on lead at idle: does
engine speed decrease equally at each cylindeR Yes Go to Step 9
NO Go to next step
Is injector operating sound heard at idle? [ Yes Go to Step 7
t- NO Stop engine and go to next step
Yes Check if injector resistance is OK
CT page F3-41 Is there battery voltage at each injector connec-
tor (No.1 (P), No.2 (R), No.3 QV), No.4 (0)) with
ignition switch ON?
Resktance: Approx. 2.110
(at 20*C [68*F))
4 if it is, check wiring
(ECU - Injector)
c3 If it is not, replace itijector
Go to next step
NO
Is there battery v&age at injector resistor (W/R)
I .Yes
with ignition switch ON? Check mjeotor resistor
4 tf OK, check for short circuit in wir-
ing (Injector resistor-Injector)
e3 If not OK,’ replace injector resistor
Check for open circuit in wiring (Main
relay (FUEL INJ relay)-Injector resistor)
Go to next step
t NO 1
Is strong blue soark visible at each disconnected Yes
‘Check ‘high-tension lead
4 If UK. check distributor cap and
rotor .
c3 If not OK, replace high-tension lead
‘-F3-29

TROUBLESHOOTING GUiDE F3
15 ENGINE STALLS ON DECELERATION
IESCRIP-
l Engrne unexpectedly stops running dunng or after deceleration
[iON l Idle condition normal.
TROUBLESHOOT1NG HtNTS]
ingrne speed drops too much when releasrng accelerator
3 Idle-speed misadjustment @I Loose connector disconnected by force of deceleration
3 Fuel-cut contrd malfunction
TEP lNSPECTlON ACTION
1 1s idle condition normal? Yes Go to next step
tdle speed: 800 f 50 rpm (in neutral)
NO Adjust or perform Troubleshooting, Nos.
8-I 1 “ROUGH IDLE”
(Refer to Workshop Manual
(1203-I o-89F))
2 Is “00” displayed on Self-Diagnosis Checker Yes Go to next step
with ignition switch ON?
SYSTEM SELECT: 1 NO Service Code No. displayed
Check for cause (Refer to specified
check sequence) ET page F3-16
“88” flashes
Check ECU termrnal 1 F voltage
Voltage: Battery voltage
(ignition switch ON) r;r page F346
W:SELFTEST
e If OK, replace ECU CI page F3-3
4 If not OK, check wirtng
(ECU - Self-Diagnosis Checker)
3 Does Self-Diagnosis Checker Monitor Lamp with Yes Go to next step
lgnttlon switch UN show that switches operate
correctly?
NO Lamp not ON or OFF with specified
switch
Check for cause (Refer to specified
check sequence)
W: SEtF TEST Lamp slways ON
Check wiring between
(ECU terminal 1 D - Self-Diagnosis
Checker)
4 Are ECU ?erminal voltages OK? Yes Go to next step
(especially IV, 20, 20, ZU, 2V.
and 20) v page F346 No
Check for cause
5 Check for poor connection of foltowing parts YC?S Repair or replace
l ignrtion coil l Igniter l Olstribdor l High-tension lead
NO Go to next step l Injector. l Injector resistor l Ctrcuit-opening relay . l ECU
F3-35

F3 TROUBLESHOOTING GUIDE
STEP INSPECTION ACTlON
6 Is dashpot correctly adjusted? Yes Go to next step
c
Dashpot set speed: Approx. 3,500 rpm
No Adjust dashpot
7
Try known good ECU; does condition
Improve?
w page F3-3
13EOF3-336
16 ENGINE STALLS SUDDENLY (INTERMITTENT)
DESCRIP.
l Engine intermittently stops running
TION l Before stalling, engine conditron is OK
TROUBLESHOOTING HINTS]
@ intermittently no spark or no fuel injection caused by ve-
hlcle vibratron, acceleratton, or deceleration
l Poor connectlon in wiring harness
iTEP INSPECTION ACTfON
1 Is “00” displayed on Self-Oiagnoss Checker Yes Go to next step
with lgnltlon swrtch ON?
NO Service Code No. displayed
Check for cause (Refer to speclfled
check sequence).
Note CT page F3-16
l When checking wiring harness and
connectors, tap, move, and wiggle
suspect sensor and/or harness to
recreate problem
“88” flashes ’
Check ECU terminal IF voltage
Voltage: Battery voltage
{ignition swttch ON) w page F3-45
4 If OK, replace ECU
4 If not OK, check wiring
(ECU - Self-Diagnosis Checker)
2 Check for poor connection of foliowrng parts
Yes Reparr or replace
l lgnltfon coil l Igniter l Distributor l t-flgh-tensron lead
No Go to next step l Injector l Injector reststor l Circutt-opening relay l ECU
3 Are ECU terminal voltages OK? Yes Go to Troubleshbotrng No. 2
(especially 16, 2A, 2B, and 2C) .“CRANKS NORMALLY BUT WILL NOT
w page F3-45 START (NO COMBUSTION)”
w page F3-20
Note
. No Check for cause
l When. checking voltages, tap, move, and
wiggle harness and connector to recreate
problem
* lrlrl m-7
F3-36
7.8-l

F3 FUEL SYSTEM
t 3EoF3-344
1
FUEL SYSTEM
FUEL PUMP
inspection
Fuel pump operation
1. Connect the diagnosis connector F/P and GND terminals
by using a jumper wire.
2. Remove the fuel filler cap.
3. Turn ON the ignition switch.
4.
Listen at the filler inlet for the operational sou.nd of the fuel
pump.
5. Install the fuel filler cap.
6. If no sound is heard, measure the voltage between the fuel
pump connector (G/R) to a ground.
Voltage: 8attey vo kage
7. If not as specified, check the circuit opening relay and circuit.
8. ff as specified, check fur continuity between fuel pump con-
nector (G/R) and (B).
9. If there is continuity, reptace the fuel pump.
10. If there is no continuity, repair the ground circuit.
f3EOF3.345
13EOF3-346 FUEL PUMP RESlSTORlRELAY
System Operation
1. Remove the rear seat cushion.
2. Measure the voltage at the fuel pump connector terminal
A (G/R).
Voltage
I
Cranking
1 Battery voltage
Ignition switch ON ov 3. If not as specified, perform the following inspections, and
repair or replace as necessary.
l Fuel pump resistor/relay resistance
(Refer to page F3-41.)
l ECU 11 terminal voltage (Refer to page F3-45.)
l Wiring harness and connector
F3-40
ii e -
*
_~ --
C --
A-'

-,
-,
--
--
-1
E
7
2
I
i 3EAR SE
--

FUEL SYSTEM F3
13EOF3.34
c I 13EOF3-364 FUEL PUMP CONNECTOR
/
!NSTALL CLAMPS
I
l nspection
1, Disconnect the resistor/relay connector.
2. Ground the fuel pump resistor relay terminal D.
3. Apply battery voltage and check for continuity as shown.
Terminal C
Continuity between A and I3
Battery voltage applied NO
ov Yes
4. Measure the resistance between terminals E and F.
Resistance : 0.38--0.42Q (at 2O*C {6S°F 1)
PRESSURE REGULATOR
Inspection
Fuel line pressure
Warning
l Before performing the following operation, release
the fuel pressure from the fuel system to reduce the
possibility of injury or fire. (Refer to page F3-21.)
1. Disconnect the negative battery terminal.
2. Connect a fuel pressure gauge between the fuel filter and
the fuel main hose. (install clamps as shown.) , .
I
3. Connect the negative battery terminal.
/t.
4, Start the engine and run it at idle.
5. Measure the fuel line pressure.
Fuel line pressure:
206-255 kPa [ 2.1-2.6 kgflcml, 30-37 psi )
6. Disconnect the upper vacuum hose from the pressure regu-
lator and measure the fuel line pressure.
Fuel line pressure:
304-392 kPa (3.1-4.0 kgf/cm2, 44-57 psi )
F3-41