1992 MAZDA PROTEGE ESP

TROUBLESHOOTING GUIDE
TEP INSPECTION ACTION
4 Check if ECU terminal voltages are OK Yes Go to next step
MTX...Especially IC, 20 and 2Q
ATX... Especially lC, 2E and 3D v page F-150
No Check for cause ~3‘ page F-151
5
Check for air leakage of intake air system com- Yes Repair or replace
ponents
No Go to next step
6 Check if engine starts when water thermosensor Yes Check water thermosensor c7 page F-158 is disconnected
Check for correct engine compression 82-10 ’ No
Check engine condition CIP page Bl-10
Engine compression: 82-10
l BP SOHC l Worn piston, piston rings or cylinder 834 kPa (8.5 kg/cm*, 121 psi)300 rpm
wall
l BP DOHC l Defective cylinder head gasket 883 kPa (9.0 kg/cm*, 128 psi)-300 rpm l Distorted cylinder head
l B8 l Improper valve seating 932 kPa (9.5 kg/cm*, 135 psi)300 rpm *Valve sticking in guide
9 Check if spark plugs are OK Yes Go to next step CT- page G-18
1.0-l .l mm
(0.039-0.043 in) DAMAGE AND
DETERIORATION No Clean, or replace c7 page G-18
10 Try known good ECU and check if condition
improves CT- page F-149
23UOFX-01 I
F-33

TROUBLESHOOTING GUIDE F
CY page F-l 16
ATX... Especially IC, 2E and 3D
OK, repair or replace wire
ST” and check
for correct ignition timing at idl
*Worn piston, piston rings or cylinder
l Defective cylinder head gasket l Distorted cylinder head l Improper valve seating
aValve sticking in guide
known good ECU and check if condition
23UOFX-02
F-37

F TROUBLESHOOTING GUIDE
8 ROUGH IDLE/ENGINE STALLS AT IDLE - ALWAYS
bESCRIP- l Engine starts normally but stalls or vibrates excessively at idle in every condition
‘ION TROUBLESHOOTING HINTS]
D Air/Fuel mixture too lean @ Incorrect idle speed
l Air leakage l Idle speed misadjustment l Fuel injection control malfunction l Idle speed control malfunction
*Low fuel line pressure @ One or more spark plugs not firing
3 One or more injectors clogged or not operating @ Low engine compression
3 Low intake air amount @ Airflow meter stuck INSPECTION
1
1
2
3
4
5
6
- Check if “00” is displayed on Self-Diagnosis
Checker with ignition switch ON w page F-82
SYSTEM2ELECT: 1
M v’SELECT SW: A TEST
Check if ECU terminal voltages are OK
MTX...Especially 2D, 20 and 2Q
ATX... Especially 2B, 2E and 3D CT page F-150
Disconnect high-tension lead at idle and check if
engine speed decreases equally at each cylinder
Check for injector operating sound at idle
Check if battery voltage exists at injector connec-
tor (W/R) wire
Check if strong blue spark is visible at discon-
nected high-tension lead
, Yes No Service Code No. displayed
Check for cause (Refer to specified
:heck sequence) “88” flashes
Check ECU terminal IF voltage CT page F-150
Specification: Battery voltage
(Ignition switch ON)
3 If OK, replace ECU w page F-149 3 If not OK, check wiring between
ECU and Self-Diaanosis Checker Yes
Go to next step No
Check for cause Yes
Go to Step 8 No
Go to next step
Go to Step 6
Go to Step 5 Yes
No
Yes
No
Yes
No I-
30 to next step w page F-83
0 page F-151
Check if injector resistance is OK c7 page F-131
Resistance: Approx. 12-l 852
c3 If OK, check wiring between ECU
and injector
c3 If not OK, replace injector w page F-131
Check wiring between ECU and injector
Go to next step
Check high-tension lead w page G-17
Q If OK, check distributor cap and
rotor w page G-22
c3 If not OK, replace high-tension lead
F-42

F TROUBLESHOOTING GUIDE
9
ROUGH IDLE/ENGINE STALLS AT IDLE - BEFORE WARM-UP
DESCRIP-
*Engine speed low or engine stalls or vibrates excessively at idle during warm-up
TION
[TROUBLESHOOTING HINTS]
@ Low intake air amount
@ Low fuel injection control
l Airflow meter stuck
*Fuel injection control malfunction
*Air cleaner element clogged
(Correction for coolant temperature)
*Air valve
@ Poor atomization
*Low RVP (summer) fuel used in cold weather
w page F-83
W: SELF TEST Check ECU terminal 1F voltage
w page F-150
Specification: Battery voltage
(Ignition switch ON)
c3 If OK, replace ECU c3 page F-149
* If not OK, check wiring between
ECU and Self-Diagnosis Checker
Vacuum: More than 450 mmHg (17.7 inHg)
AX.. Especially 2B, 2E and 30
w page F-150
NO Check for cause CT page F-181
5 Disconnect ISC valve connector and check if en-
Yes Go to next step
gine speed increases after warm-up
CT page F-l 18
No Replace ISC valve c3 page F-109
F-44

TROUBLESHOOTING GUIDE F
12 ROUGH IDLE/ENGINE STALLS JUST AFTER STARTING
DESCRIP-
*Engine starts normally but vibrates excessively or stalls just after starting (acceleration from idle) TION
*Idle conditions are normal in the other conditions [TROUBLESHOOTING HINTS]
@ Fuel injection control system or idle speed control sys-
@ Idle speed misadjustment
tern malfunction @ Ignition timing misadjustment
*Start signal not input to ECU iTEl
-s-- 3
4
5 INSPECTION
-T- ACTION
Check if “00” is displayed on Self-Diagnosis
Checker with ignition switch ON w page F-82
SYSTEM,SELECT: I
r -SELECT SW: A
Check if ECU terminal voltages are OK
MTX...Especially 1 N
ATX... Especially 1T w page F-150
Connect System Selector to diagnosis connector
and set Test Switch to “SELF TEST” and check
for correct ignition timing at idle after warm-up w page F-78
Ignition timing (BTDC)
l BP DOHC : 9”-11 o l BP SOHC : 4O--6O
l B8 : 60-80
Check continuity between throttle sensor termi-
nals IDL and E CT page F-159
MTX
Clearance between throttle
lever and stopper
MTX O.lmm (0.004 in)
1 .Omm (0.039 in)
ATX 0.1 mm (0.004 in)
0.6mm (0.024 in) Continuity
Yes
No
Yes
No
Try known good ECU and check if condition
mproves w page F-149 Yes
No
Yes
Go to next step No
Check for cause Yes
In same condition as Step 3 inspection
and apply parking brake
Check for correct idle speed w page F-80
Idle speed: 700-800 rpm
No
Adjust Yes
Go to next step No
Adjust Go to next step Service Code No. displayed
Check for cause (Refer to specified
check sequence) w page F-83
“88” flashes
Check ECU terminal IF voltage w page F-150
Specification: Battery voltage
(Ignition switch ON)
d If OK, replace ECU w page F-149
* If not OK, check wiring between
ECU and Self-Diagnosis Checker c7 page F-151
3 If OK, go to next step
3 If not OK, adjust idle speed w page F-80
w page F-79
w page F-159
F-49

TROUBLESHOOTING GUIDE F
iTEP INSPECTION ACTION
6 Connect System Selector to diagnosis connector Yes Go to next step
and set Test Switch to “SELF TEST” when en-
gine is cold
Check if engine speed decreases as engine
warms up
w page F-l 16
No Check air valve w page F-116
7
Disconnect ISC valve connector at idle and Yes Go to next step
check if idle speed increases
CT page F-l 16
No
Check ISC valve CT page F-l 16
8
Pinch PCV hose with pliers and check if engine Yes Check PCV valve
speed decreases w page F-136
Go to next step
9 Check if ECU terminal voltages are OK
Yes Try known good ECU and check if con-
MTX...Especially 20, 20 and 2Q
dition improves
ATX... Especially 28, 2E and 3D CT page F-149
CT page F-152 No Check for cause w page F-153
23UOFX-079
F-51

F TROUBLESHOOTING GUIDE
15
ENGINE STALLS ON DECELERATION
DESCRIP-
l Engine unexpectedly stops running while decelerating or after deceleration
TION l Idle condition normal
[TROUBLESHOOTING HINTS]
Engine speed drops too much when releasing accelerator or poor connector connection disconnected by deceleration
force
3 Idle speed control malfunction
3 Fuel cut control malfunction @ Idle speed misadjustment
TEP INSPECTION
ACTION
1
Check if idle condition is normal Yes
Go to next step
No Adjust or perform troubleshooting
Nos. 8-11 “ROUGH IDLE” v page F-42
F-48
--
2
Check if “00” is displayed on Self-Diagnosis Yes Go to next step
Checker with ignition switch ON
W page F-82 No
SYSTEM SELECT: 1 Service Code No. displayed
Check for cause (Refer to specified
check sequence) w page F-83
“88” flashes
Check ECU terminal IF voltage LIT= page F-150
Specification: Battery voltage
(Ignition switch ON)
W: SELF TEST + If OK, replace ECU w page F-149
Q If not OK, check wiring between
ECU and Self-Diagnosis Checker
3 Check switches for correct operation with Self-
Yes Go to next step
Diagnosis Checker Monitor Lamp with ignition
switch ON
w page F-105 No
Lamp not ON or OFF with specified
switch
Check for cause (Refer to specified
check sequence) CT page F-106
-,-y/
,’ Lamp always ON
Check wiring between ECU terminal 1 D
and Self-Diagnosis Checker
W: SELF
TEST
4 Check if ECU terminal voltages are OK
Yes Go to next step
MTX...Especially IV, 2D, 20, 2U, 2V and 2Q
ATX... Especially 28, 2E, 30, 3U, and 3V
w page F-150 No Check for cause w page F-151
5
Check for poor connection of following parts
Yes Repair or replace
. Ignition coil
l Igniter l Distributor
-- l High-tension lead
No l Injector Go to next step l Circuit opening relay l ECU
F-54

TROUBLESHOOTING GUIDE
16 ENGINE STALLS SUDDENLY (INTERMITTENT)
DESCRIP- l Engine intermittently stops running
TION l Before stalling, engine condition OK [TROUBLESHOOTING HINTS]
@ Intermittently no spark or no-fuel injection caused by ve-
hicle vibration, acceleration, or deceleration
*Poor connection in wire harness
3 INSPECTION
Check if “00” is displayed on Self-Diagnosis
Checker with ignition switch ON c7 page F-82
g
-%ELECT SW: A
Check for poor connection of following parts l ignition coil
l igniter l Distributor l High-tension lead l lniector
l Ci;cuit opening relay l ECU
Check if ECU terminal voltages are OK
MTX...Especially lB, 2A, 28 and 2C
ATX... Especially lB, 3A, 38 and 3C w page F-150
Note
l When checking voltages, tap, move, and
wiggle harness and connector to recreate
problem
Yes
No Service Code No. displayed
Check for cause (Refer to specified
check sequence) Note
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 w page F-150
Specification: Battery voltage
(Ignition switch ON)
c3 If OK, replace ECU CT= page F-149
+ If not OK, check wiring between
ECU and Self-Diagnosis Checker
Yes
Repair or replace
No Go to next step
Yes
No
T ACTION
Go to next step w page F-83
Go to Troubleshooting No.2
‘CRANKS NORMALLY BUT WILL NOT
START (NO COMBUSTION)” CT- page F-30
Check for cause D page F-151
F-56