ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-71
1. Throttle body
2. Fuel feed hose
GoodNo good1. Injector connector
STEPACTIONYESNO
6Check PCV valve for clogging (See Section 6E1).
Is it in good condition?Go to Step 7.Replace PCV valve.
7Check EVAP Canister Purge Valve for Closing.
1) Disconnect purge hose (1) from EVAP canister.
2) Place finger against the end of disconnected hose.
3) Check that vacuum is not felt there, when engine is
cool and running at idle. See Fig. 5.
Is vacuum felt?Check EVAP
control system
(See Section 6E1).Go to Step 8.
8Check intake manifold pressure sensor for performance
(See Section 6E1).
Is it in good condition?Go to Step 9.Repair or replace.
9Check engine coolant temp. sensor for performance
(See Section 6E1).
Is it in good condition?Go to Step 10.Replace engine
coolant temp.
sensor.
10Check parts or system which can cause engine rough
idle or poor performance.
–Engine compression (See Section 6A).
–Valve lash (See Section 6A).
–Valve timing (Timing belt installation. See Section 6A).
Are they in good condition?Check wire harness
and connection of
ECM (PCM) ground,
ignition system and
fuel injector for
intermittent open
and short.Repair or replace.
Fig. 1 for Step 3 Fig. 2 for Step 3 Fig. 3 for Step 4
Fig. 4 for Step 5 Fig. 5 for Step 7
ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-77
1) 2) 3) 4) 35 – 45 mph
(55 – 65 km / h)
30 – 40 mph
(50 – 60 km / h)
DTC CONFIRMATION PROCEDURE
WARNING:
When performing a road test, select a place where there is no traffic or possibility of a traffic accident
and be very careful during testing to avoid occurrence of an accident.
Road test should be carried out with 2 persons, a driver and tester, on a level road.
1) Turn ignition switch OFF.
Clear DTC with ignition switch ON, check vehicle and environmental condition for:
–Altitude (barometric pressure): 2400 m, 8000 ft or less (560 mmHg, 75 kPa or more)
–Ambient temp.: –10C, 14F or higher
–Intake air temp.: 70C, 158F or lower
–Engine coolant temp.: 70 – 11 0C, 158 – 230F
2) Start engine and drive vehicle at 40 – 47 mph, 65 – 75 km / h for 15 min. or longer.
While this driving, if “Catalyst Monitoring TEST COMPLETED” is displayed in “READINESS TESTS” mode and
DTC is not displayed in “DTC” mode, confirmation test is completed.
If “TEST NOT COMPLTD” is still being displayed, continue test driving.
3) Decrease vehicle speed at 28 – 34 mph, 45 – 55 km / h, and hold throttle valve at that opening position for 2 min.
and confirm that short term fuel trim vary within –20% –+20% range.
4) Stop vehicle (do not turn ignition switch OFF) and confirm test results according to following “Test Result Con-
firmation Flow Table”.
Test Result Confirmation Flow Table
STEPACTIONYESNO
1Check DTC in “DTC” mode and pending DTC in
“ON BOARD TEST” or “PENDING DTC” mode.
Is DTC or pending DTC displayed?Proceed to applicable
DTC Diag. Flow Table.Go to Step 2.
2Set scan tool to “READINESS TESTS” mode and
check if testing has been completed.
Is test completed?No DTC is detected
(confirmation test is
completed).Repeat DTC
confirmation
procedure.
ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-79
Main
fuseMain relay
To other valves
EVAP canister
purge valve
EVAP canister
purge valveSurge
tank
Tank pressure
control valveFuel vapor separator
Fuel filter cap
Fuel
level
sensor
Fuel tank EVAP
canister
DTC P0443 PURGE CONTROL VALVE CIRCUIT MALFUNCTION
CIRCUIT DESCRIPTION
DTC DETECTING CONDITIONPOSSIBLE CAUSE
Canister Purge control valve circuit is opened
or shorted.“R/G” circuit open or short
“W/BI” circuit open
Canister purge valve malfunction
DTC CONFIRMATION PROCEDURE
1) Clear DTC with ignition switch ON.
2) Select “DTC” mode on scan tool and check DTC.
INSPECTION
STEPACTIONYESNO
1Check EVAP canister purge valve operation
1) With ignition switch OFF, disconnect coupler
from canister purge valve.
2) Check resistance of EVAP canister purge
valve. See Fig. 1.
Resistance between
two terminals : 30 – 34 Ω at 20C (68F)
Resistance between
terminal and body : 1M Ω or higher
Is it as specified?“R/G” circuit open or
short.Replace EVAP canister
purge valve.
Main
fuseMain relay
EFE heater EFE heater relay
6-90 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
DTC P1250 EARLY FUEL EVAPORATION (EFE) HEATER CIRCUIT
MALFUNCTION
CIRCUIT DESCRIPTION
DTC DETECTING CONDITIONPOSSIBLE CAUSE
Voltage low at terminal C01-12 during engine
warming up
or
Voltage high at terminal C01-12 after engine
warming up
2 driving cycle detection logic, continuous
monitoring“Y/R”, “W” or “W/B” circuit open or short
EFE heater relay malfunction
EFE heater malfunction
ECM (PCM) malfunction
DTC CONFIRMATION PROCEDURE
1) Turn ignition switch OFF.
2) Clear DTC with ignition switch ON.
3) Check vehicle and environmental condition for:
–Altitude (barometric pressure): 2400 m, 8000 ft or less (560 mmHg, 75 kPa or more)
–Ambient temp: –10C, 14F or higher
–Intake air temp: 70C, 158F or lower
4) Start cool engine and warm it up to normal operating temperature.
5) Check pending DTC in “ON BOARD TEST” or “PENDING DTC” mode and DTC in “DTC” mode.
1. Fuel pump
2. Fuel filter
3. Throttle body
4. Fuel injector
5. Fuel pressure regulator6. Special tool
(Fuel pressure gauge &
3-way joint)
7. Fuel feed line
8. Fuel return line
6-100 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
TABLE B-3 FUEL PRESSURE CHECK
INSPECTION
STEPACTIONYESNO
1Check Fuel Pressure (Refer to Section 6E1 for details).
1) Release fuel pressure from fuel feed line.
2) Install fuel pressure gauge.
3) Check fuel pressure by repeating ignition switch
ON and OFF. See Fig. 1.
Is fuel pressure then 160 – 210 kPa (1.6 – 2.1 kg / cm
2,
22.7 – 29.9 psi)?
Go to Step 2.Go to Step 4.
2Is 90 kPa (0.9 kg / cm2, 12.8 psi) or higher fuel
pressure retained for 1 minute after fuel pump is
stopped at Step 1?Normal fuel pressure.Go to Step 3.
31) Start engine and warm it up to normal operating
temperature.
2) Keep it running at specified idle speed.
Is fuel pressure then within 90 – 140 kPa
(0.9 – 1.4 kg / cm
2, 12.8 – 20.0 psi)?
Normal fuel pressure.Clogged vacuum
passage for fuel
pressure regulator
or
Faulty fuel pressure
regulator.
4Is there fuel leakage from fuel feed line hose, pipe or
their joint?Fuel leakage from
hose, pipe or joint.Go to Step 10.
5Was fuel pressure higher than specification in Step 1?Go to Step 6.Go to Step 7.
61) Disconnect fuel return hose from throttle body and
connect new return hose to it.
2) Insert the other end of new return hose into
approved gasoline container.
3) Operate fuel pump.
Is specified fuel pressure obtained then?Restricted fuel return
hose or pipe.Faulty fuel pressure
regulator.
7Was no fuel pressure supplied in Step 1?Go to Step 8.Go to Step 9.
ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-101
Fig. 1 for Step 1
1. Fuel pressure gauge & 3way joint
STEPACTIONYESNO
8With fuel pump operated and fuel return hose
blocked by pinching it, is fuel pressure applied?Faulty fuel pressure
regulator.Shortage of fuel or fuel
pump or its circuit
defective (refer to B-2
FUEL PUMP ANDITS
CIRCUIT CHECK).
91) Operate fuel pump.
2) With fuel return hose blocked by pinching it, check
fuel pressure.
Is it 450 kPa (4.5 kg / cm
2, 63.9 psi) or more?
Faulty fuel pressure
regulator.Clogged fuel filter,
Restricted fuel feed
hose or pipe,
Faulty fuel pump or
Fuel leakage from
hose connection in
fuel tank.
101) Disconnect fuel return hose from throttle body and
connect new return hose to it.
2) Insert the other end of new return hose into
approved gasoline container.
3) Check again if specified pressure is retained.
While doing so, does fuel come out of return hose?Faulty fuel pressure
regulator.Fuel leakage from
injector,
Fuel leakage from
between injector
and throttle body,
Faulty fuel pump
(faulty check valve
in fuel pump) or
Fuel leakage from
fuel pressure
regulator
diaphragm.
6-1-2 ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13)
DTC P0300 Random Misfire
Detected 6-1- 69. . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0301 Cylinder 1 Misfire
Detected 6-1- 69. . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0302 Cylinder 2 Misfire
Detected 6-1- 69. . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0303 Cylinder 3 Misfire
Detected 6-1- 69. . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0304 Cylinder 4 Misfire
Detected 6-1- 69. . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0335 CKP Sensor Circuit
Malfunction 6-1- 73. . . . . . . . . . . . . . . . . . . . . . . .
DTC P0340 CMP Sensor Circuit
Malfunction 6-1- 75. . . . . . . . . . . . . . . . . . . . . . . .
DTC P0400 EGR Flow Malfunction 6-1- 78. . . .
DTC P0420 Catalyst System
Efficiency Below Threshold 6-1- 81. . . . . . . . . .
DTC P0443 Purge Control Valve Circuit
Malfunction 6-1- 84. . . . . . . . . . . . . . . . . . . . . . . .
DTC P0480 Radiator Fan Control
System Malfunction 6-1- 85. . . . . . . . . . . . . . . . .
DTC P0500 Vehicle Speed Sensor
Malfunction 6-1- 87. . . . . . . . . . . . . . . . . . . . . . . .
DTC P0505 Idle Control System
Malfunction 6-1- 91. . . . . . . . . . . . . . . . . . . . . . . . DTC P0601 Internal Control Module
Memory Check Sum Error 6-1- 93. . . . . . . . . . .
DTC P1450 Barometric Pressure
Sensor Low / High Input 6-1- 94. . . . . . . . . . . . .
DTC P1451 Barometric Pressure Sensor
Performance Problem 6-1- 94. . . . . . . . . . . . . . .
DTC P1500 Engine Starter Signal
Circuit Malfunction 6-1- 96. . . . . . . . . . . . . . . . . .
DTC P1510 ECM (PCM) Back-up
Power Supply Malfunction 6-1- 97. . . . . . . . . . .
Table B-1 Fuel Injector Circuit Check 6-1- 98. . .
Table B-2 Fuel Pump and Its Circuit
Check 6-1- 99. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table B-3 Fuel Pressure Check 6-1-101. . . . . . . .
Table B-4 A / C Signal Circuits Check 6-1-103. . .
Table B-5 PSP Switch Signal Circuit
Check 6-1-104. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table B-6 Electric Load Signal Circuit
Check 6-1-105. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table B-7 Radiator Cooling Fan Control
System Check 6-1-106. . . . . . . . . . . . . . . . . . . . .
SPECIAL TOOLS6-1-108 . . . . . . . . . . . . . . . . . . . . .
HOSE CONNECTION
Clamp securely at a position 3 to
7mm (0.12–0.27 in.) from hose end. With short pipe, fit hose as far as it reaches pipe joint as
shown.
Hose
Pipe
ClampClamps securely at a position
3 to 7 mm (0.12–0.27 in.)
from hose end.
With following type pipe, fit hose as far as its peripheral
projection as shown.
Clamp securely at a position
3 to 7 mm (0.12–0.27 in.)
from hose end.
With bent pipe, fit hose as its bent part as shown or till pipe
is about 20 to 30 mm (0.79–1.18 in.) into the hose.
Clamp securely at a
position 3 to 7 mm
(0.12–0.27 in.) from hose
end.
With straight pipe, fit hose till pipe is, about 20 to 30 mm
(0.79–1.18 in.) into the hose.
Hose
20 to 30 mm
(0.79–1.18 in.)
Clamp
6-1-4 ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13)
PRECAUTION ON FUEL SYSTEM SERVICE
Work must be done with no smoking, in a well-ventilated area and
away from any open flames.
As fuel feed line (between fuel pump and fuel delivery pipe) is still
under high fuel pressure even after engine was stopped, loosen-
ing or disconnecting fuel feed line directly may cause dangerous
spout of fuel to occur where loosened or disconnected.
Before loosening or disconnecting fuel feed line, make sure to re-
lease fuel pressure according to “FUEL PRESSURE RELIEF
PROCEDURE”. A small amount of fuel may be released after the
fuel line is disconnected. In order to reduce the chance of person-
al injury, cover the fitting to be disconnected with a shop cloth. Put
that cloth in an approved container when disconnection is com-
pleted.
Never run engine with fuel pump relay disconnected when engine
and exhaust system are hot.
Fuel or fuel vapor hose connection varies with each type of pipe.
When reconnecting fuel or fuel vapor hose, be sure to connect
and clamp each hose correctly referring to left figure Hose Con-
nection.
After connecting, make sure that it has no twist or kink.
When installing injector or fuel delivery pipe, lubricate its O-ring
with spindle oil or gasoline.
When connecting fuel pipe flare nut, first tighten flare nut by hand
and then tighten it to specified torque.