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
TROUBLESHOOTING GUIDE
17 HESITATES/STUMBLES ON ACCELERATION
bESCRIP-
*Flat spot occurs just after accelerator depressed or mild jerking occurs during acceleration
‘ION TROUBLESHOOTING HINTS]
0 Air/Fuel mixture becomes lean when depressing accelerator l Fuel injection control malfunction
(Correction for accelerating condition)
*Air leakage
l Fuel line pressure decreases l Spark advance control malfunction TEP INSPECTION ACTION
1 Check if “00” is displayed on Self-Diagnosis Yes Go to next step
Checker with ignition switch ON W page F-82 ’ No
Service Code No. displayed
SYSTEM SELECT: 1 Check for cause (Refer to specified
check sequence) w page F-83
“88” flashes
W: SELF TEST Check ECU terminal IF voltage CT= page F-150
Specification: Battery voltage
(Ignition switch ON) c3 If OK, replace ECU c? page F-149 * If not OK, check wiring between
ECU and Self-Diagnosis Checker Vacuum: More than 450 mmHg (17.7 InHg)
tern components
Replace air cleaner element 4
Check if ECU terminal voltages are OK
Yes Go to next step
MTX...Especiaily 2L
ATX... Especially lT, 2F, and 21 w page F-150
No Check for cause cp page F-151
5
Check if throttle linkage is correctly installed and
Yes Go to next step
operates freely w page F-l 14 ~~
Correct, clean, or replace as required
any binding or damaged linkage and
adjust cable deflection at throttle body w page F-l 14
6
Check continuity between throttle sensor termi- Yes Go to next step
nals IDL and E w page F-189
MTX
A-I-X 1
J E
IDL
Clearance between throttle
lever and stopper Continuity
MTX 0.1 mm (0.004 in) Yes
1 .Omm (0.039 in) No
ATX 0.1 mm (0.004 in)
Yes
0.6mm (0.024 in) No
No Adjust w page F-189
F-57
22 KNOCKING
DESCRIP- *Abnormal combustion accompanied by audible “pinging” noise
I-ION
[TROUBLESHOOTING HINTS]
3 Incorrect ignition timing (Too advanced)
@ Air/Fuel mixture too lean
3 Carbon deposits in cylinder
*Fuel injection amount not correct
3 Overheating
l Fuel line pressure decreases while accelerating
TEP INSPECTION
ACTION
1 Connect System Selector to diagnosis connector
Yes Go to next step
and set Test Switch to “SELF TEST” and check
for correct ignition timing at idle after warm-up
CT page F-79
Ignition timing (BTDC)
l BP DOHC : go-1 1 o l BP SOHC : 4”-6O
’ B6 No
Adjust a page F-79
2 Check if “00” is displayed on Self-Diagnosis
Yes Go to next step
Checker with ignition switch ON
W page F-62
No
Service Code No. displayed
Check for cause (Refer to specified
check sequence) w page F-63
“88” flashes
Check ECU terminal 1F voltage CT page F-150
Specification: Battery voltage
(Ignition switch ON)
c3 If OK, replace ECU w page F-149
W: SELF TEST c3 If not OK, check wiring between
ECU and Self-Diagnosis Checker
3 Check for correct intake manifold vacuum at idle
Yes Go to next step
VaCUUm: More than 450 mmHg (17.7 inHg) No
Check for air leakage of intake air sys-
tem components
4
Check for correct engine compression
Yes Go to next step
w page Bl-10
B2-10
Engine compression (Minimum):
l BP DOHC
883 kPa (9.0 kg/cm’, 128 psi)-300 rpm
l BP SOHC
834 kPa (8.5 kg/cm*, 121 psi)300 rpm
l B6
932 kPa (9.5 kg/cm’, 135 psi)300 rpm No High compression
Check engine condition CI page 81-10
62-l 0 l Carbon deposits
F-71
TROUBLESHOOTING GUIDE F
26 POOR FUEL ECONOMY
DESCRIP-
l Fuel economy unsatisfactory TION
[TROUBLESHOOTING HINTS]
While fuel consumption is drastically increased by city driving, short-run operation, stop and go driving, extended winter
warm-up periods, etc., as opposed to “trip” mileage, an attempt should be made to determine these factors when con-
fronted with “poor mileage” conditions. However, since the operator is not always at fault, the following is offered.
@II Operator depressing accelerator more than usual due to
@ Air/Fuel mixture too rich
low engine power
l Poor ignition *High fuel line pressure
@ Alcohol blended fuel used
*Low intake air amount
l Electronic spark advance control system malfunction @ High vehicle load l Low tire pressure
*Clutch slipping/ATX slipping l Incorrect tire size l Exhaust component restricted l Brake dragging ;TEP
INSPECTION ACTION
1
Check factors other than engine Yes
Go to next step
l Low tire pressure = Section Q 9 Unrecommended tire srze v Section Q l Clutch slipping w Section H l Brake dragging No
0 Section P Repair
l Exhaust component restricted cz= page F-136
2
Check if air hoses are connected correctly - Yes
Go to next step CI page F-109
No
Repair 3
Check if “00” IS displayed on Self-Diagnosis
Yes
Checker with ignition switch ON Go to next step W page F-82 No
SYSTEM SELECT: 1 Service Code No. displayed Check for cause (Refer to specified
check sequence) w page F-63
“88” flashes
Check ECU terminal 1F voltage w page F-150
Specification: Battery voltage
(Ignition switch ON)
* If OK, replace ECU CT= page F-149 e If not OK, check wiring between
ECU and Self-Diagnosis Checker 4
Check for correct intake manifold vacuum at idle
Yes Go to next step Vacuum: More than 450 mmHg (17.7 inHg) No
Check for air leakage at intake air sys-
tem components 5
Check if air cleaner element is clean Yes
Go to next step CT= page F-79
No
Replace air cleaner element
F-75
SELF-DIAGNOSIS FUNCTION F
PREPARATION
SST
49 6019 9AO
System Selector For
diagnosis 49 HO18 9Al
Self-Diagnosis
Checker For
diagnosis
SERVICE CODE NUMBER
Inspection Procedure
1. Connect the SST to the diagnosis connector.
2. Set switch @to position 1.
3. Set TEST SW to SELF-TEST position.
23UOFX-048
03UOFX.059
I
4. Connect the SST to the System Selector and a ground
5. Set the select switch to position A.
6. Turn the ignition switch to ON.
7. Verify that 88 flashes on the digital display and the buzzer
sounds for 3 sec. after turning the ignition switch ON.
8. If 88 does not flash, check the main relay (FUEL INJ relay)
(Refer to page F-172) power supply circuit, and diagno-
sis connector wiring.
9. If 88 flashes and the buzzer sounds continuously for more
than 20 sec., check for a short circuit between the engine
control unit terminal 1 F and the diagnosis connector. Re-
place the engine control unit if necessary and perform Steps
3 and 7 again.
23UOFX-049 IO. Note any code numbers and check for the causes by refer-
ring to the check sequences shown on pages F-88
through F-103. Repair as necessary.
Note
l Cancel the code numbers by performing the after-
repair procedure following repairs.
(Refer to page F-104.)
I 23UOFX-050
F--83
F SELF-DIAGNOSIS FUNCTION
23UOFX-08: 3
03UOFX.086
i:a pj
MONITOR
SELECT El
03UOFX-:6
7
I
7
After-repair Procedure
1. Cancel the memory of malfunctions by disconnecting the
negative battery cable for
at least 20 seconds. Reconnect
the negative battery cable.
2. Connect the
SST (System Selector) to the diagnosis con-
nector.
3. Set the switch @to position 1.
4. Set TEST SW to SELF-TEST.
5. Connect the
SST (Self-Diagnosis Checker) to the System
Selector and a ground.
6. Set the select switch of the Self-Diagnosis Checker to posi-
tion A.
7. Turn the ignition switch ON.
8. Start and warm up the engine, then run it at
2,000 rpm for
three minutes.
9. Verity that no code numbers are displayed.
F-l 04
CONTROL SYSTEM F
VB: Battery voltage
incorrect voltage POBSible cause
Alwvs OV’ l ROOM IOA fuse burned l Open circuit in wiring from ROOM IOA fuse to ECU terminal 1A
Always OV
l Main relay malfunction (Refer to page F-171) l Open or short circuit in wiring from main relay to ECU terminal 1B
I
Always OV (Starter turns) l Open or short circuit in wiring from starter interlock switch (USA), ignition
switch (CANADA), to ECU terminal 1C
I
Always OV
Always Vs
Always approx. 5V
l Main relay (FUEL IWJ relay) malfunction (Refer to page F-171) l Open circuit in wiring from main relay to diagnosis connector terminal +B l Open or short circuit in wiring from diagnosis connector terminal MEN to
ECU terminal 1D
l Poor connection at ECU connector l ECU malfunction
l ECU malfunction
Always below
23 MIL always ON
MIL never ON
l Short circuit in wiring from combination meter to ECU terminal 1E l ECU malfunction
l Open circuit in wiring from combination meter to ECU terminal 1E
I
Always Ve l Poor connection at ECU connector l ECU malfunction
Always below
2.5V
Always
VB
No display on Self- * Main relay (FUEL INJ relay) malfunction (Refer to page F-171)
Diagnosis Checker l Open circuit in wiring from main relay to diagnosis connector terminal +B
“88” displayed and
l Open or short circuit in wiring from diagnosis connector terminal FEN to
buzzer sounds con- ECU terminal 1F
tinuously
l Poor connectron at ECU connector l ECU malfunction
Always OV
l Short circuit in wiring from igniter to ECU terminal 1G
I -
I -
I
I -
I -
I
Always below
2.5V
Always VB AIC does not operate l A/C relay malfunction (Refer to page U-55) l Open circurt in wiring from ignition switch to A/C relay l Open circuit in wiring from A/C relay to ECU terminal 1J
A/C switch OFF but
l Short circuit in wiring from A/C relay to ECU terminal IJ
AIC operates l ECU malfunction
l Poor connection at ECU connector l ECU malfunction
Always below l.OV
l Short circuit in wiring from diagnosis connector terminal TEN to ECU termi-
nal 1K
Always Vs
l Open circuit in wiring from diagnosis connector terminal TEN to ECU termi-
nal 1K
l Open circuit in wiring from diaonosis connector terminal GND to ground
Always below
2.W
Always Va DRL ON when ignition
l Short circuit in wiring from DRL relay to ECU terminal IL
switch ON l Short circuit in wiring from DRL relay to DRL unit
DRL never ON
l Open circuit in wiring from DRL relay to ignition switch
l Parking brake switch always ON l DRL unit malfunction (Refer to page T-33)
23UOFX- 134
F-l 51